1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" 2 "http://www.w3.org/TR/html4/loose.dtd"> 3<html> 4<head> 5 <title>The XSLT C library for GNOME</title> 6 <meta name="GENERATOR" content="amaya 8.5, see http://www.w3.org/Amaya/"> 7 <meta http-equiv="Content-Type" content="text/html"> 8</head> 9 10<body bgcolor="#ffffff"> 11<h1 align="center">The XSLT C library for GNOME</h1> 12 13<h1 style="text-align: center">libxslt</h1> 14 15<p>Libxslt is the <a href="http://www.w3.org/TR/xslt">XSLT</a> C library 16developed for the GNOME project. XSLT itself is a an XML language to define 17transformation for XML. Libxslt is based on <a 18href="http://xmlsoft.org/">libxml2</a> the XML C library developed for the 19GNOME project. It also implements most of the <a 20href="http://www.exslt.org/">EXSLT</a> set of processor-portable extensions 21functions and some of Saxon's evaluate and expressions extensions.</p> 22 23<p>People can either embed the library in their application or use xsltproc 24the command line processing tool. This library is free software and can be 25reused in commercial applications (see the <a href="intro.html">intro</a>)</p> 26 27<p>External documents:</p> 28<ul> 29 <li>John Fleck wrote <a href="tutorial/libxslttutorial.html">a tutorial for 30 libxslt</a></li> 31 <li><a href="xsltproc.html">xsltproc user manual</a></li> 32 <li><a href="http://xmlsoft.org/">the libxml documentation</a></li> 33</ul> 34 35<p></p> 36 37<p>Logo designed by <a href="mailto:liyanage@access.ch">Marc Liyanage</a>.</p> 38 39<h2><a name="Introducti">Introduction</a></h2> 40 41<p>This document describes <a href="http://xmlsoft.org/XSLT/">libxslt</a>, 42the <a href="http://www.w3.org/TR/xslt">XSLT</a> C library developed for the 43<a href="http://www.gnome.org/">GNOME</a> project.</p> 44 45<p>Here are some key points about libxslt:</p> 46<ul> 47 <li>Libxslt is a C implementation</li> 48 <li>Libxslt is based on libxml for XML parsing, tree manipulation and XPath 49 support</li> 50 <li>It is written in plain C, making as few assumptions as possible, and 51 sticking closely to ANSI C/POSIX for easy embedding. Should works on 52 Linux/Unix/Windows.</li> 53 <li>This library is released under the <a 54 href="http://www.opensource.org/licenses/mit-license.html">MIT 55 Licence</a></li> 56 <li>Though not designed primarily with performances in mind, libxslt seems 57 to be a relatively fast processor.</li> 58</ul> 59 60<h2><a name="Documentat">Documentation</a></h2> 61 62<p>There are some on-line resources about using libxslt:</p> 63<ol> 64 <li>Check the <a href="html/libxslt-lib.html#LIBXSLT-LIB">API 65 documentation</a> automatically extracted from code comments (using the 66 program apibuild.py, developed for libxml, together with the xsl script 67 'newapi.xsl' and the libxslt xsltproc program).</li> 68 <li>Look at the <a href="http://mail.gnome.org/archives/xslt/">mailing-list 69 archive</a>.</li> 70 <li>Of course since libxslt is based on libxml, it's a good idea to at 71 least read <a href="http://xmlsoft.org/">libxml description</a></li> 72</ol> 73 74<h2><a name="Reporting">Reporting bugs and getting help</a></h2> 75 76<p>If you need help with the XSLT language itself, here are a number of 77useful resources:</p> 78<ul> 79 <li>I strongly suggest to subscribe to <a 80 href="http://www.mulberrytech.com/xsl/xsl-list">XSL-list</a>, check <a 81 href="http://www.biglist.com/lists/xsl-list/archives/">the XSL-list 82 archives</a></li> 83 <li>The <a href="http://www.dpawson.co.uk/xsl/xslfaq.html">XSL FAQ</a>.</li> 84 <li>The <a 85 href="http://www.nwalsh.com/docs/tutorials/xsl/xsl/slides.html">tutorial</a> 86 written by Paul Grosso and Norman Walsh is a very good on-line 87 introdution to the language.</li> 88 <li>The <a 89 href="http://www.zvon.org/xxl/XSLTutorial/Books/Book1/index.html">only 90 Zvon XSLT tutorial</a> details a lot of constructs with examples.</li> 91 <li><a href="http://www.jenitennison.com/xslt/index.html">Jeni Tennison's 92 XSLT</a> pages provide links to a lot of answers</li> 93 <li>the <a href="http://incrementaldevelopment.com/xsltrick/">Gallery of 94 XSLT Tricks</a> provides non-standard use case of XSLT</li> 95 <li>And I suggest to buy Michael Kay "XSLT Programmer's Reference" book 96 published by <a href="http://www.wrox.com/">Wrox</a> if you plan to work 97 seriously with XSLT in the future.</li> 98</ul> 99 100<p>Well, bugs or missing features are always possible, and I will make a 101point of fixing them in a timely fashion. The best way to report a bug is to 102use the <a 103href="http://bugzilla.gnome.org/enter_bug.cgi?product=libxslt">GNOME bug 104tracking database</a> (make sure to use the "libxslt" module name). Before 105filing a bug, check the <a 106href="http://bugzilla.gnome.org/buglist.cgi?product=libxslt">list of existing 107libxslt bugs</a> to make sure it hasn't already been filed. I look at reports 108there regularly and it's good to have a reminder when a bug is still open. Be 109sure to specify that the bug is for the package libxslt.</p> 110 111<p>For small problems you can try to get help on IRC, the #xml channel on 112irc.gnome.org (port 6667) usually have a few person subscribed which may help 113(but there is no guarantee and if a real issue is raised it should go on the 114mailing-list for archival).</p> 115 116<p>There is also a mailing-list <a 117href="mailto:xslt@gnome.org">xslt@gnome.org</a> for libxslt, with an <a 118href="http://mail.gnome.org/archives/xslt/">on-line archive</a>. To subscribe 119to this list, please visit the <a 120href="http://mail.gnome.org/mailman/listinfo/xslt">associated Web</a> page 121and follow the instructions.</p> 122 123<p>Alternatively, you can just send the bug to the <a 124href="mailto:xslt@gnome.org">xslt@gnome.org</a> list, if it's really libxslt 125related I will approve it.. Please do not send me mail directly especially 126for portability problem, it makes things really harder to track and in some 127cases I'm not the best person to answer a given question, ask the list 128instead. <strong>Do not send code, I won't debug it</strong> (but patches are 129really appreciated!).</p> 130 131<p>Please note that with the current amount of virus and SPAM, sending mail 132to the list without being subscribed won't work. There is *far too many 133bounces* (in the order of a thousand a day !) I cannot approve them manually 134anymore. If your mail to the list bounced waiting for administrator approval, 135it is LOST ! Repost it and fix the problem triggering the error. Also please 136note that <span style="color: #FF0000; background-color: #FFFFFF">emails with 137a legal warning asking to not copy or redistribute freely the information 138they contain</span> are <strong>NOT</strong> acceptable for the mailing-list, 139such mail will as much as possible be discarded automatically, and are less 140likely to be answered if they made it to the list, <strong>DO NOT</strong> 141post to the list from an email address where such legal requirements are 142automatically added, get private paying support if you can't share 143information.</p> 144 145<p>Check the following too <span style="color: #E50000">before 146posting</span>:</p> 147<ul> 148 <li><a href="search.php">use the search engine</a> to get information 149 related to your problem.</li> 150 <li>make sure you are <a href="ftp://xmlsoft.org/libxslt/">using a recent 151 version</a>, and that the problem still shows up in those</li> 152 <li>check the <a href="http://mail.gnome.org/archives/xslt/">list 153 archives</a> to see if the problem was reported already, in this case 154 there is probably a fix available, similarly check the <a 155 href="http://bugzilla.gnome.org/buglist.cgi?product=libxslt">registered 156 open bugs</a></li> 157 <li>make sure you can reproduce the bug with xsltproc, a very useful thing 158 to do is run the transformation with -v argument and redirect the 159 standard error to a file, then search in this file for the transformation 160 logs just preceding the possible problem</li> 161 <li>Please send the command showing the error as well as the input and 162 stylesheet (as an attachment)</li> 163</ul> 164 165<p>Then send the bug with associated information to reproduce it to the <a 166href="mailto:xslt@gnome.org">xslt@gnome.org</a> list; if it's really libxslt 167related I will approve it. Please do not send mail to me directly, it makes 168things really hard to track and in some cases I am not the best person to 169answer a given question, ask on the list.</p> 170 171<p>To <span style="color: #E50000">be really clear about support</span>:</p> 172<ul> 173 <li>Support or help <span style="color: #E50000">request MUST be sent to 174 the list or on bugzilla</span> in case of problems, so that the Question 175 and Answers can be shared publicly. Failing to do so carries the implicit 176 message "I want free support but I don't want to share the benefits with 177 others" and is not welcome. I will automatically Carbon-Copy the 178 xslt@gnome.org mailing list for any technical reply made about libxml2 or 179 libxslt.</li> 180 <li>There is <span style="color: #E50000">no guarantee for support</span>, 181 if your question remains unanswered after a week, repost it, making sure 182 you gave all the detail needed and the information requested.</li> 183 <li>Failing to provide information as requested or double checking first 184 for prior feedback also carries the implicit message "the time of the 185 library maintainers is less valuable than my time" and might not be 186 welcome.</li> 187</ul> 188 189<p>Of course, bugs reports with a suggested patch for fixing them will 190probably be processed faster.</p> 191 192<p>If you're looking for help, a quick look at <a 193href="http://mail.gnome.org/archives/xslt/">the list archive</a> may actually 194provide the answer, I usually send source samples when answering libxslt 195usage questions. The <a 196href="html/libxslt-lib.html#LIBXSLT-LIB">auto-generated documentation</a> is 197not as polished as I would like (I need to learn more about Docbook), but 198it's a good starting point.</p> 199 200<h2><a name="help">How to help</a></h2> 201 202<p>You can help the project in various ways, the best thing to do first is to 203subscribe to the mailing-list as explained before, check the <a 204href="http://mail.gnome.org/archives/xslt/">archives </a>and the <a 205href="http://bugzilla.gnome.org/buglist.cgi?product=libxslt">GNOME bug 206database:</a>:</p> 207<ol> 208 <li>provide patches when you find problems</li> 209 <li>provide the diffs when you port libxslt to a new platform. They may not 210 be integrated in all cases but help pinpointing portability problems 211 and</li> 212 <li>provide documentation fixes (either as patches to the code comments or 213 as HTML diffs).</li> 214 <li>provide new documentations pieces (translations, examples, etc ...)</li> 215 <li>Check the TODO file and try to close one of the items</li> 216 <li>take one of the points raised in the archive or the bug database and 217 provide a fix. <a href="mailto:daniel@veillard.com">Get in touch with me 218 </a>before to avoid synchronization problems and check that the suggested 219 fix will fit in nicely :-)</li> 220</ol> 221 222<h2><a name="Downloads">Downloads</a></h2> 223 224<p>The latest versions of libxslt can be found on the <a 225href="ftp://xmlsoft.org/libxslt/">xmlsoft.org</a> server. (NOTE that 226you need the <a href="http://rpmfind.net/linux/RPM/libxml2.html">libxml2</a>, 227<a href="http://rpmfind.net/linux/RPM/libxml2-devel.html">libxml2-devel</a>, 228<a href="http://rpmfind.net/linux/RPM/libxslt.html">libxslt</a> and <a 229href="http://rpmfind.net/linux/RPM/libxslt-devel.html">libxslt-devel</a> 230packages installed to compile applications using libxslt.) <a 231href="mailto:igor@zlatkovic.com">Igor Zlatkovic</a> is now the maintainer of 232the Windows port, <a 233href="http://www.zlatkovic.com/projects/libxml/index.html">he provides 234binaries</a>. <a href="http://opencsw.org/">CSW</a> provides 235<a href="http://opencsw.org/packages/libxslt">Solaris binaries</a>, and 236<a href="mailto:Steve.Ball@explain.com.au">Steve Ball</a> provides <a 237href="http://www.explain.com.au/oss/libxml2xslt.html">Mac Os X 238binaries</a>.</p> 239 240<p><a name="Snapshot">Snapshot:</a></p> 241<ul> 242 <li>Code from the GNOME GIT base libxslt module, updated hourly <a 243 href="ftp://xmlsoft.org/libxml2/libxslt-git-snapshot.tar.gz">libxslt-git-snapshot.tar.gz</a>.</li> 244</ul> 245 246<p><a name="Contribs">Contribs:</a></p> 247 248<p>I do accept external contributions, especially if compiling on another 249platform, get in touch with me to upload the package. I will keep them in the 250<a href="ftp://xmlsoft.org/libxml2/contribs/">contrib directory</a></p> 251 252<p>Libxslt is also available from GIT:</p> 253<ul> 254 <li><p>See <a href="http://git.gnome.org/browse/libxslt/">libxslt Git web</a>. 255 To checkout a local tree use:</p> 256 <pre>git clone git://git.gnome.org/libxslt</pre> 257 </li> 258 <li>The <strong>libxml2</strong> module is also present 259 <a href="http://git.gnome.org/browse/libxml2/">there</a></li> 260</ul> 261 262 263<h2><a name="FAQ">FAQ</a></h2> 264<ol> 265 <li><em>Troubles compiling or linking programs using libxslt</em> 266 <p>Usually the problem comes from the fact that the compiler doesn't get 267 the right compilation or linking flags. There is a small shell script 268 <code>xslt-config</code> which is installed as part of libxslt usual 269 install process which provides those flags. Use</p> 270 <p><code>xslt-config --cflags</code></p> 271 <p>to get the compilation flags and</p> 272 <p><code>xslt-config --libs</code></p> 273 <p>to get the linker flags. Usually this is done directly from the 274 Makefile as:</p> 275 <p><code>CFLAGS=`xslt-config --cflags`</code></p> 276 <p><code>LIBS=`xslt-config --libs`</code></p> 277 <p>Note also that if you use the EXSLT extensions from the program then 278 you should prepend <code>-lexslt</code> to the LIBS options</p> 279 </li> 280 <li><em>passing parameters on the xsltproc command line doesn't work</em> 281 <p><em>xsltproc --param test alpha foo.xsl foo.xml</em></p> 282 <p><em>the param does not get passed and ends up as ""</em></p> 283 <p>In a nutshell do a double escaping at the shell prompt:</p> 284 <p>xsltproc --param test "'alpha'" foo.xsl foo.xml</p> 285 <p>i.e. the string value is surrounded by " and ' then terminated by ' 286 and ". Libxslt interpret the parameter values as XPath expressions, so 287 the string -><code>alpha</code><- is intepreted as the node set 288 matching this string. You really want -><code>'alpha'</code><- to 289 be passed to the processor. And to allow this you need to escape the 290 quotes at the shell level using -><code>"'alpha'"</code><- .</p> 291 <p>or use</p> 292 <p>xsltproc --stringparam test alpha foo.xsl foo.xml</p> 293 </li> 294 <li><em>Is there C++ bindings ?</em> 295 <p>Yes for example <a 296 href="http://pmade.org/pjones/software/xmlwrapp/">xmlwrapp</a> , see <a 297 href="python.html">the related pages about bindings</a></p> 298 </li> 299</ol> 300 301<h2><a name="News">News</a></h2> 302 303<p>See the <a href="http://git.gnome.org/browse/libxslt/">git page</a> 304to get a description of the recent commits.</p> 305 306<p>Those are the public releases made:</p> 307 308<h3>1.1.27: Sep 12 2012</h3> 309<ul> 310 <li> Portability:<br/> 311 xincludestyle wasn't protected with LIBXML_XINCLUDE_ENABLED (Michael Bonfils),<br/> 312 Portability fix for testThreads.c (IlyaS),<br/> 313 FreeBSD portability fixes (Pedro F. Giffuni),<br/> 314 check for gmtime - on mingw* hosts will enable date-time function (Roumen Petrov),<br/> 315 use only native crypto-API for mingw* hosts (Roumen Petrov),<br/> 316 autogen: Only check for libtoolize (Colin Walters),<br/> 317 minimal mingw support (Roumen Petrov),<br/> 318 configure: acconfig.h is deprecated since autoconf-2.50 (Stefan Kost),<br/> 319 Fix a small out of tree compilation issue (Hao Hu),<br/> 320 Fix python generator to not use deprecated xmllib (Daniel Veillard),<br/> 321 link python module with python library (Frederic Crozat)<br/> 322 </li> 323 324 <li> Documentation:<br/> 325 Tiny doc improvement (Daniel Veillard),<br/> 326 Various documentation fixes for docs on internals (C. M. Sperberg-McQueen)<br/> 327 </li> 328 329 <li> Bug fixes:<br/> 330 Report errors on variable use in key (Daniel Veillard),<br/> 331 The XSLT namespace string is a constant one (Daniel Veillard),<br/> 332 Fix handling of names in xsl:attribute (Nick Wellnhofer),<br/> 333 Reserved namespaces in xsl:element and xsl:attribute (Nick Wellnhofer),<br/> 334 Null-terminate result string of cry:rc4_decrypt (Nick Wellnhofer),<br/> 335 EXSLT date normalization fix (James Muscat),<br/> 336 Exit after compilation of invalid func:result (Nick Wellnhofer),<br/> 337 Fix for EXSLT func:function (Nick Wellnhofer),<br/> 338 Rewrite EXSLT string:replace to be conformant (Nick Wellnhofer),<br/> 339 Avoid a heap use after free error (Chris Evans),<br/> 340 Fix a dictionary string usage (Chris Evans),<br/> 341 Output should not include extraneous newlines when indent is off (Laurence Rowe),<br/> 342 document('') fails to return stylesheets parsed from memory (Jason Viers),<br/> 343 xsltproc should return an error code if xinclude fails (Malcolm Purvis),<br/> 344 Forwards-compatible processing of unknown top level elements (Nick Wellnhofer),<br/> 345 Fix system-property with unknown namespace (Nick Wellnhofer),<br/> 346 Hardening of code checking node types in EXSLT (Daniel Veillard),<br/> 347 Hardening of code checking node types in various entry point (Daniel Veillard),<br/> 348 Cleanup of the pattern compilation code (Daniel Veillard),<br/> 349 Fix default template processing on namespace nodes (Daniel Veillard),<br/> 350 Fix a bug in selecting XSLT elements (Daniel Veillard),<br/> 351 Fixed bug #616839 (Daniel Mustieles),<br/> 352 Fix some case of pattern parsing errors (Abhishek Arya),<br/> 353 preproc: fix the build (Stefan Kost),<br/> 354 Fix a memory leak with xsl:number (Daniel Veillard),<br/> 355 Fix a problem with ESXLT date:add() with January (money_seshu Dronamraju),<br/> 356 Fix a memory leak if compiled with Windows locale support (Daniel Veillard),<br/> 357 Fix generate-id() to not expose object addresses (Daniel Veillard),<br/> 358 Fix curlies support in literals for non-compiled AVTs (Nick Wellnhofer),<br/> 359 Allow whitespace in xsl:variable with select (Nick Wellnhofer),<br/> 360 Small fixes to locale code (Nick Wellnhofer),<br/> 361 Fix bug 602515 (Nick Wellnhofer),<br/> 362 Fix popping of vars in xsltCompilerNodePop (Nick Wellnhofer),<br/> 363 Fix direct pattern matching bug (Nick Wellnhofer)<br/> 364 </li> 365 366 <li> Improvements:<br/> 367 Add the saxon:systemId extension (Mike Hommey),<br/> 368 Add an append mode to document output (Daniel Veillard),<br/> 369 Add new tests to EXTRA_DIST (Nick Wellnhofer),<br/> 370 Test for bug #680920 (Nick Wellnhofer),<br/> 371 fix regresson in Various "make distcheck" and other fixes (Roumen Petrov),<br/> 372 Various "make distcheck" and other fixes (Daniel Richard G),<br/> 373 Fix portability to upcoming libxml2-2.9.0 (Daniel Veillard),<br/> 374 Adding --system flag support to autogen.sh (Daniel Veillard),<br/> 375 Allow per-context override of xsltMaxDepth, introduce xsltMaxVars (J�r�me Carretero),<br/> 376 autogen.sh: Honor NOCONFIGURE environment variable (Colin Walters),<br/> 377 configure: support silent automake rules if possible (Stefan Kost),<br/> 378 Precompile patterns in xsl:number (Nick Wellnhofer),<br/> 379 Fix some warnings in the refactored code (Nick Wellnhofer),<br/> 380 Adding new generated files (Daniel Veillard),<br/> 381 profiling: add callgraph report (Stefan Kost)<br/> 382 </li> 383 384 <li> Cleanups:<br/> 385 Big space and tabs cleanup (Daniel Veillard),<br/> 386 Fix authors list (Daniel Veillard),<br/> 387 Cleanups some of the test makefiles (Daniel Richard),<br/> 388 Remove .cvsignore files which are not needed anymore (Daniel Veillard),<br/> 389 Cleanup some misplaced spaces and tabs (Daniel Veillard),<br/> 390 Augment list of ignored files (Daniel Veillard),<br/> 391 configure: remove checks for isinf and isnan as those are not used anyway (Stefan Kost),<br/> 392 Point to GIT for source code and a bit of cleanup (Daniel Veillard),<br/> 393 Get rid of specific build setup and STATIC_BINARIES (Daniel Veillard)<br/> 394 </li> 395</ul> 396<h3>1.1.26: Sep 24 2009</h3> 397<ul> 398 <li> Improvement: 399 Add xsltProcessOneNode to exported symbols for lxml (Daniel Veillard) 400 </li> 401 <li> Bug fixes: 402 Fix an idness generation problem (Daniel Veillard), 403 595612 Try to fix some locking problems (Daniel Veillard), 404 Fix a crash on misformed imported stylesheets (Daniel Veillard) 405 </li> 406</ul> 407<h3>1.1.25: Sep 17 2009</h3> 408<ul> 409 <li> Features: 410 Add API versioning and various cleanups (Daniel Veillard), 411 xsl:sort lang support using the locale (Nick Wellnhofer and Roumen Petrov) 412 </li> 413 <li> Documentation: 414 Fix the download links for Solaris (Daniel Veillard), 415 Fix makefile and spec file to include doc in rpm (Daniel Veillard) 416 </li> 417 <li> Portability: 418 Make sure testThreads is linked with pthreads (Daniel Veillard), 419 Fix potential crash on debug of extensions Solaris (Ben Walton), 420 applied patch from Roumen Petrov for mingw cross compilation problems (Roumen Petrov), 421 patch from Richard Jones to build shared libs with MinGW cross-compiler (Richard Jones), 422 fix include path when compiling with MinGW (Roumen Petrov), 423 portability fixes ( Nick Wellnhofer and Roumen Petrov) 424 </li> 425 <li> Bug fixes: 426 Big fixes of pattern compilations (Nick Wellnhofer), 427 Fix uses of xmlAddChild for error handling (Daniel Veillard), 428 Detect deep recusion on function calls (Daniel Veillard), 429 Avoid an error in namespace generation (Martin), 430 Fix importing of encoding from included stylesheets (Nick Wellnhofer), 431 Fix problems with embedded stylesheets and namespaces (Martin), 432 QName parsing fix for patterns (Martin), 433 Crash compiling stylesheet with DTD (Martin), 434 Fix xsl:strip-space with namespace and wildcard (Nick Wellnhofer), 435 Fix a mutex deadlock on unregistered extensions (Nix), 436 567192 xsltproc --output option ignore --xinclude (Joachim Breitner), 437 Fix redundant headers in list (Daniel Veillard), 438 134754 Configure's --with-html-dir related fixes (Julio M. Merino Vidal), 439 305913 a serious problem in extensions reentrancy (Daniel Veillard), 440 Fix an idness issue when building the tree (Daniel Veillard), 441 Fixed indexing error reported by Ron Burk on the mailing list. (William M. Brack), 442 prevent some unchecked pointer accesses (Jake Goulding), 443 fix for CVE-2008-2935 libexslt RC4 encryption/decryption functions Daniel (Daniel Veillard), 444 avoid a quadratic behaviour when hitting duplicates (Daniel Veillard), 445 544829 fixed option --with-debugger (Arun Ragnavan), 446 541965 fixed incorrect argument popping in exsltMathAtan2Function (William M. Brack), 447 fix problem with string check for element-available (Ron Burk), 448 539741 added code to handle literal within an AVT (William M. Brack) 449 </li> 450 <li> Improvements: 451 Allow use of EXSLT outside XSLT (Martin), 452 Support Esperanto locale (Nick Wellnhofer), 453 Change how attributes are copied for id and speed (Daniel Veillard), 454 Add API versioning and various cleanups (Daniel Veillard), 455 Adding a test program to check thread reentrancy (Daniel Veillard), 456 big patch from finishing xsl:sort lang support (Roumen Petrov), 457 add xsl:sort lang support using the locale (Nick Wellnhofer) 458 </li> 459 <li> Cleanups: 460 Label xsltProcessOneNode as static (Daniel Veillard), 461 git setup (Daniel Veillard), 462 fixed typo detected by new libxml2 code (William M. Brack), 463 xsltExtFunctionLookup was defined but never implemented (Ralf Junker) 464 </li> 465</ul> 466<h3>1.1.24: May 13 2008</h3> 467<ul> 468 <li>Documentation: man page fix (Vincent Lefevre).</li> 469 <li>Bug fixes: pattern bug fix, key initialization problems, exclusion of 470 unknown namespaced element on top of stylesheets, python generator 471 syntactic cleanup (Martin)</li> 472</ul> 473<h3>1.1.23: Apr 8 2008</h3> 474<ul> 475 <li>Documentation: fix links for Cygwin DocBook setup (Philippe Bourcier), 476 xsltParseStylesheetDoc doc fix (Jason Viers), fix manpage default 477 maxdepth value </li> 478 <li>Bug fixes: python segfault (Daniel Gryniewicz), week-in-year bug fix 479 (Maurice van der Pot), fix python iterator problem (William Brack), 480 avoid garbage collection problems on str:tokenize and str:split 481 and function results (William Brack and Peter Pawlowski) 482 superfluous re-generation of keys (William Brack), remove superfluous 483 code in xsltExtInitTest (Tony Graham), func:result segfault fix 484 (William Brack), timezone offset problem (Peter Pawlowski),</li> 485 <li>Portability fixes: old gcrypt support fix (Brent Cowgill), Python 486 portability patch (Stephane Bidoul), VS 2008 fix (Rob Richard) </li> 487</ul> 488<h3>1.1.22: Aug 23 2007</h3> 489<ul> 490 <li>Bug fixes: RVT cleanup problems (William Brack), exclude-result-prefix 491 bug (William Brack), stylesheet compilation error handling (Rob Richards). 492 </li> 493 <li>Portability fixes: improve build with VS2005 (Rob Richards), 494 fixing build on AIX (Bjorn Wiberg), fix the security file checks on 495 Windows (Roland Schwarz and Rob Richards). </li> 496 <li>Improvement: add an --encoding option to xsltproc (Drazen Kacar). </li> 497</ul> 498<h3>1.1.21: Jun 12 2007</h3> 499<ul> 500 <li>Bug fixes: out of memory allocation errors (William Brack), 501 namespace problem on compound predicates (William Brack), 502 python space/tab inconsistencies (Andreas Hanke), hook xsl:message 503 to per transformation error callbacks (Shaun McCance), 504 cached RVT problem (William Brack), XPath context maintainance 505 on choose (William Brack), memory leaks in the math module (William 506 Brack), exclude-result-prefix induced namespace problem (William 507 Brack)</li> 508 <li>Build: configure setup for TRIO_REPLACE_STDIO (William Brack) 509 <li>Documentation: updated after change from CVs to SVN (William Brack)</li> 510</ul> 511<h3>1.1.20: Jan 17 2007</h3> 512<ul> 513 <li>Portability fixes: strict aliasing fix (Marcus Meissner), BSD portability 514 patches (Roland Illig)</li> 515 <li>Bug fixes: Result Value Tree handling fix (William Brack), function 516 parameters fix (William), uninitialized variable (Kjartan Maraas), 517 empty text node handling (William), plugin support and test fixes (William), 518 fragment support fixes (William)</li> 519 <li>Improvements: python stylesheet compare and transform context 520 access (Nic Ferrier), EXSLT string replace support (Joel Reed), 521 xsltproc better low level error handling (Mike Hommey and William)</li> 522</ul> 523<h3>1.1.19: Nov 29 2006</h3> 524<ul> 525 <li>Bug fixes: entities within attributes (William Brack), Python detection 526 problem (Joseph Sacco), in-scope namespace bug (Mike Hommey), Result 527 value tree caching bug (William Brack)</li> 528</ul> 529<h3>1.1.18: Oct 26 2006</h3> 530<ul> 531 <li>portability and build fixes: DESTDIR problem, build paths in python 532 shared lib, compile when libxml2 doesn't support XInclude (Gary Coady).</li> 533 <li>bug fixes: a number of namespace related bugs (Kasimier Buchcik), 534 parameters bugs (Kasimier Buchcik), proximity position in predicates 535 of match patterns (Kasimier), exslt-node-set troubles with strings 536 (Kasimier), CDATA serialization, Python floats and booleans XPath 537 conversions, XInclude support fixes, RVT cleanup problem (William Brack 538 and Kasimier), attribute checking in stylesheets (Kasimier), xsltForEach 539 context problem (Kasimier), security check should pass full URLs (Shane 540 Corgatelli), security cleanup patch (Mikhail Zabaluev), some python 541 accessor for stylesheet were broken, memory errors when compiling 542 stylesheets (Mike Hommey), EXSLT current date end-of-month problem 543 (William Brack).</li> 544 <li>improvements: refactoring of namespace handling, value-of impleemntation 545 and template internal processing (Kasimier Buchcik), new xsltproc 546 flag to apply Xinclude to stylesheets.</li> 547 <li>documentation: xsltproc man pages (Daniel Leidert), tests updates 548 (William Brack), various typo fixes (Daniel Leidert), comments on 549 versions macros (Peter Breitenlohner).</li> 550</ul> 551<h3>1.1.17: Jun 6 2006</h3> 552<ul> 553 <li>portability fixes: python detection</li> 554 <li>bug fixes: some regression tests, attribute/namespaces output (Kasimier 555 Buchcik), problem in mixed xsl:value-of and xsl:text uses (Kasimier)</li> 556 <li>improvements: internal refactoring (Kasimier Buchcik), use of the XPath 557 object cache in libxml2-2.6.25 (Kasimier)</li> 558</ul> 559 560<h3>1.1.16: May 01 2006</h3> 561<ul> 562 <li>portability fixes: EXSLT date/time on Solaris and IRIX (Albert Chin), 563 HP-UX build (Albert Chin), 564 <li>build fixes: Python detection(Joseph Sacco), plugin configurei 565 (Joel Reed)</li> 566 <li>bug fixes: pattern compilation fix(William Brack), EXSLT date/time 567 fix (Thomas Broyer), EXSLT function bug, potential loop on variable 568 eval, startup race (Christopher Palmer), debug statement left in python 569 (Nic Ferrier), various cleanup based on Coverity reports), error on 570 Out of memory condition (Charles Hardin), various namespace prefixes 571 fixes (Kasimier Buchcik), </li> 572 <li>improvement: speed up sortingi, start of internals refactoring (Kasimier 573 Buchcik)</li> 574 <li>documentation: man page fixes and updates (Daniel Leidert) 575</ul> 576 577<h3>1.1.15: Sep 04 2005</h3> 578<ul> 579 <li>build fixes: Windows build cleanups and updates (Igor Zlatkovic), 580 remove jhbuild warnings</li> 581 <li>bug fixes: negative number formatting (William Brack), number 582 formatting per mille definition (William Brack), XInclude default values 583 (William), text copy bugs (William), bug related to xmlXPathContext size, 584 reuse libxml2 memory management for text nodes, dictionary text bug, 585 forbid variables in match (needs libxml2-2.6.21)</li> 586 <li>improvements: EXSLT dyn:map (Mark Vakoc),</li> 587 <li>documentation: EXSLT date and time functions namespace in man (Jonathan 588 Wakely)</li> 589</ul> 590 591<h3>1.1.14: Apr 02 2005</h3> 592<ul> 593 <li>bug fixes: text node on stylesheet document without a dictionary 594 (William Brack), more checking of XSLT syntax, calling xsltInit() 595 multiple times, mode values interning raised by Mark Vakoc, bug in 596 pattern matching with ancestors, bug in patterna matching with cascading 597 select, xinclude and document() problem, build outside of source tree 598 (Mike Castle)</li> 599 <li>improvement: added a --nodict mode to xsltproc to check problems for 600 docuemtns without dictionaries</li> 601</ul> 602 603<h3>1.1.13: Mar 13 2005</h3> 604<ul> 605 <li>build fixes: 64bits cleanup (William Brack), python 2.4 test (William), 606 LIBXSLT_VERSION_EXTRA on Windows (William), Windows makefiles fixes (Joel 607 Reed), libgcrypt-devel requires for RPM spec.</li> 608 <li>bug fixes: exslt day-of-week-in-month (Sal Paradise), xsl:call-template 609 should not change the current template rule (William Brack), evaluation 610 of global variables (William Brack), RVT's in XPath predicates (William), 611 namespace URI on template names (Mark Vakoc), stat() for Windows patch 612 (Aleksey Gurtovoy), pattern expression fixes (William Brack), out of 613 memory detection misses (William), parserOptions propagation (William), 614 exclude-result-prefixes fix (William), // patten fix (William).</li> 615 <li>extensions: module support (Joel Reed), dictionary based speedups 616 trying to get rid of xmlStrEqual as much as possible.</li> 617 <li>documentation: added Wiki (Joel Reed)</li> 618</ul> 619 620<h3>1.1.12: Oct 29 2004</h3> 621<ul> 622 <li>build fixes: warnings removal (William).</li> 623 <li>bug fixes: attribute document pointer fix (Mark Vakoc), exslt date 624 negative periods (William Brack), generated tree structure fixes, 625 namespace lookup fix, use reentrant gmtime_r (William Brack), 626 exslt:funtion namespace fix (William), potential NULL pointer reference 627 (Dennis Dams, William), force string interning on generated 628 documents.</li> 629 <li>documentation: update of the second tutorial (Panagiotis Louridas), add 630 exslt doc in rpm packages, fix the xsltproc man page.</li> 631</ul> 632 633<h3>1.1.11: Sep 29 2004</h3> 634<ul> 635 <li>bug fixes: xsl:include problems (William Brack), UTF8 number pattern 636 (William), date-time validation (William), namespace fix (William), 637 various Exslt date fixes (William), error callback fixes, leak with 638 namespaced global variable, attempt to fix a weird problem #153137</li> 639 <li>improvements: exslt:date-sum tests (Derek Poon)</li> 640 <li>documentation: second tutorial by Panagiotis Lourida</li> 641</ul> 642 643<h3>1.1.10: Aug 31 2004</h3> 644<ul> 645 <li>build fix: NUL in c file blocking compilation on Solaris, Windows build 646 (Igor Zlatkovic)</li> 647 <li>fix: key initialization problem (William Brack)</li> 648 <li>documentation: fixed missing man page description for --path</li> 649</ul> 650 651<h3>1.1.9: Aug 22 2004</h3> 652<ul> 653 <li>build fixes: missing tests (William Brack), Python dependancies, Python 654 on 64bits boxes, --with-crypto flag (Rob Richards),</li> 655 <li>fixes: RVT key handling (William), Python binding (William and Sitsofe 656 Wheeler), key and XPath troubles (William), template priority on imports 657 (William), str:tokenize with empty strings (William), #default namespace 658 alias behaviour (William), doc ordering missing for main document 659 (William), 64bit bug (Andreas Schwab)</li> 660 <li>improvements: EXSLT date:sum added (Joel Reed), hook for document 661 loading for David Hyatt, xsltproc --nodtdattr to avoid defaulting DTD 662 attributes, extend xsltproc --version with CVS stamp (William).</li> 663 <li>Documentation: web page problem reported by Oliver Stoeneberg</li> 664</ul> 665 666<h3>1.1.8: July 5 2004</h3> 667<ul> 668 <li>build fixes: Windows runtime options (Oliver Stoeneberg), Windows 669 binary package layout (Igor Zlatkovic), libgcrypt version test and link 670 (William)</li> 671 <li>documentation: fix libxslt namespace name in doc (William)</li> 672 <li>bug fixes: undefined namespace message (William Brack), search engine 673 (William), multiple namespace fixups (William), namespace fix for key 674 evaluation (William), Python memory debug bindings,</li> 675 <li>improvements: crypto extensions for exslt (Joel Reed, William)</li> 676</ul> 677 678<h3>1.1.7: May 17 2004</h3> 679<ul> 680 <li>build fix: warning about localtime_r on Solaris</li> 681 <li>bug fix: UTF8 string tokenize (William Brack), subtle memory 682 corruption, linefeed after comment at document level (William), 683 disable-output-escaping problem (William), pattern compilation in deep 684 imported stylesheets (William), namespace extension prefix bug, 685 libxslt.m4 bug (Edward Rudd), namespace lookup for attribute, namespaced 686 DOCTYPE name</li> 687</ul> 688 689<h3>1.1.6: Apr 18 2004</h3> 690<ul> 691 <li>2 bug fixes about keys fixed one by Mark Vakoc</li> 692</ul> 693 694<h3>1.1.5: Mar 23 2004</h3> 695<ul> 696 <li>performance: use dictionary lookup for variables</li> 697 <li>remove use of _private from source documents</li> 698 <li>cleanup of "make tests" output</li> 699 <li>bugfixes: AVT in local variables, use localtime_r to avoid thread 700 troubles (William), dictionary handling bug (William), limited number of 701 stubstitutions in AVT (William), tokenize fix for UTF-8 (William), 702 superfluous namespace (William), xsltproc error code on 703 <xsl:message> halt, OpenVMS fix, dictionary reference counting 704 change.</li> 705</ul> 706 707<h3>1.1.4: Feb 23 2004</h3> 708<ul> 709 <li>bugfixes: attributes without doc (Mariano Su�rez-Alvarez), problem with 710 Yelp, extension problem</li> 711 <li>display extension modules (Steve Little)</li> 712 <li>Windows compilation patch (Mark Vadoc), Mingw (Mikhail Grushinskiy)</li> 713</ul> 714 715<h3>1.1.3: Feb 16 2004</h3> 716<ul> 717 <li>Rewrote the Attribute Value Template code, new XPath compilation 718 interfaces, dictionary reuses for XSLT with potential for serious 719 performance improvements.</li> 720 <li>bug fixes: portability (William Brack), key() in node-set() results 721 (William), comment before doctype (William), math and node-set() problems 722 (William), cdata element and default namespace (William), behaviour on 723 unknown XSLT elements (Stefan Kost), priority of "//foo" patterns 724 (William), xsl:element and xsl:attribute QName check (William), comments 725 with -- (William), attribute namespace (William), check for ?> in PI 726 (William)</li> 727 <li>Documentations: cleanup (John Fleck and William)</li> 728 <li>Python: patch for OS-X (Gianni Ceccarelli), enums export (Stephane 729 bidoul)</li> 730</ul> 731 732<h3>1.1.2: Dec 24 2003</h3> 733<ul> 734 <li>Documentation fixes (John Fleck, William Brack), EXSLT documentation 735 (William Brack)</li> 736 <li>Windows compilation fixes for MSVC and Mingw (Igor Zlatkovic)</li> 737 <li>Bug fixes: exslt:date returning NULL strings (William Brack), 738 namespaces output (William Brack), key and namespace definition problem, 739 passing options down to the document() parser, xsl:number fixes (William 740 Brack)</li> 741</ul> 742 743<h3>1.1.1: Dec 10 2003</h3> 744<ul> 745 <li>code cleanup (William Brack)</li> 746 <li>Windows: Makefile improvements (Igor Zlatkovic)</li> 747 <li>documentation improvements: William Brack, libexslt man page (Jonathan 748 Wakely)</li> 749 <li>param in EXSLT functions (Shaun McCance)</li> 750 <li>XSLT debugging improvements (Mark Vakoc)</li> 751 <li>bug fixes: number formatting (Bjorn Reese), exslt:tokenize (William 752 Brack), key selector parsing with | reported by Oleg Paraschenko, 753 xsl:element with computed namespaces (William Brack), xslt:import/include 754 recursion detection (William Brack), exslt:function used in keys (William 755 Brack), bug when CDATA_SECTION are foun in the tree (William Brack), 756 entities handling when using XInclude.</li> 757</ul> 758 759<h3>1.1.0: Nov 4 2003</h3> 760<ul> 761 <li>Removed DocBook SGML broken support</li> 762 <li>fix xsl:key to work with PIs</li> 763 <li>Makefile and build improvement (Graham Wilson), build cleanup (William 764 Brack), macro fix (Justin Fletcher), build outside of source tree (Roumen 765 Petrov)</li> 766 <li>xsltproc option display fix (Alexey Efimov), --load-trace (Crutcher 767 Dunnavant)</li> 768 <li>Python: never use stdout for error</li> 769 <li>extension memory error fix (Karl Eichwalder)</li> 770 <li>header path fixes (Steve Ball)</li> 771 <li>added saxon:line-number() to libexslt (Brett Kail)</li> 772 <li>Fix some tortuous template problems when using predicates (William 773 Brack)</li> 774 <li>Debugger status patch (Kasimier Buchcik)</li> 775 <li>Use new libxml2-2.6.x APIs for faster processing</li> 776 <li>Make sure xsl:sort is empty</li> 777 <li>Fixed a bug in default processing of attributes</li> 778 <li>Removes the deprecated breakpoint library</li> 779 <li>detect invalid names on templates (William Brack)</li> 780 <li>fix exslt:document (and similar) base handling problem</li> 781</ul> 782 783<h3>1.0.33: Sep 12 2003</h3> 784 785<p>This is a bugfix only release</p> 786<ul> 787 <li>error message missing argument (William Brack)</li> 788 <li>mode not cascaded in template fallbacks (William Brack)</li> 789 <li>catch redefinition of parameter/variables (William Brack)</li> 790 <li>multiple keys with same namespace name (William Brack)</li> 791 <li>patch for compilation using MingW on Windows (Mikhail Grushinskiy)</li> 792 <li>header export macros for Windows (Igor Zlatkovic)</li> 793 <li>cdata-section-elements handling of namespaced names</li> 794 <li>compilation without libxml2 XPointer support (Mark Vadoc)</li> 795 <li>apply-templates crash (William Brack)</li> 796 <li>bug with imported templates (William Brack)</li> 797 <li>imported attribute-sets merging bug (DocBook) (William Brack)</li> 798</ul> 799 800<h3>1.0.32: Aug 9 2003</h3> 801<ul> 802 <li>bugfixes: xsltSaveResultToFile() python binding (Chris Jaeger), EXSLT 803 function (William Brack), RVT for globals (William Brack), EXSLT date 804 (William Brack), 805 <p>speed of large text output, xsl:copy with attributes, strip-space and 806 namespaces prefix, fix for --path xsltproc option, EXST:tokenize (Shaun 807 McCance), EXSLT:seconds (William Brack), sort with multiple keys (William 808 Brack), checking of { and } for attribute value templates (William 809 Brack)</p> 810 </li> 811 <li>Python bindings for extension elements (Sean Treadway)</li> 812 <li>EXSLT:split added (Shaun McCance)</li> 813 <li>portability fixes for HP-UX/Solaris/IRIX (William Brack)</li> 814 <li>doc cleanup</li> 815</ul> 816 817<h3>1.0.31: Jul 6 2003</h3> 818<ul> 819 <li>bugfixes: xsl:copy on namespace nodes, AVT for xsl:sort order, fix for 820 the debugger (Keith Isdale), output filename limitation, trio.h and 821 triodef.h added (Albert Chin), EXSLT node-set (Peter Breitenlohner), 822 xsltChoose and whitespace (Igor Zlatkovic), 823 <p>stylesheet compilation (Igor Zlatkovic), NaN and sort (William Brack), 824 RVT bug introduced in 1.0.30</p> 825 </li> 826 <li>avoid generating &quot; (fix in libxml2-2.5.8)</li> 827 <li>fix 64bit cleaness problem and compilation troubles introduced in 828 1.0.30</li> 829 <li>Windows makefile generation (Igor Zlatkovic)</li> 830 <li>HP-UX portability fix</li> 831</ul> 832 833<h3>1.0.30: May 4 2003</h3> 834<ul> 835 <li>Fixes and new APIs to handle Result Value Trees and avoid leaks</li> 836 <li>Fixes for: EXSLT math pow() function (Charles Bozeman), global 837 parameter and global variables mismatch, a segfault on pattern 838 compilation errors, namespace copy in xsl:copy-of, python generator 839 problem, OpenVMS trio update, premature call to xsltFreeStackElem (Igor), 840 current node when templates applies to attributes</li> 841</ul> 842 843<h3>1.0.29: Apr 1 2003</h3> 844<ul> 845 <li>performance improvements especially for large flat documents</li> 846 <li>bug fixes: Result Value Tree handling, XML IDs, keys(), extra namespace 847 declarations with xsl:elements.</li> 848 <li>portability: python and trio fixes (Albert Chin), python on Solaris 849 (Ben Phillips)</li> 850</ul> 851 852<h3>1.0.28: Mar 24 2003</h3> 853<ul> 854 <li>fixed node() in patterns semantic.</li> 855 <li>fixed a memory access problem in format-number()</li> 856 <li>fixed stack overflow in recursive global variable or params</li> 857 <li>cleaned up Result Value Tree handling, and fixed a couple of old bugs 858 in the process</li> 859</ul> 860 861<h3>1.0.27: Feb 24 2003</h3> 862<ul> 863 <li>bug fixes: spurious xmlns:nsX="" generation, serialization bug (in 864 libxml2), a namespace copy problem, errors in the RPM spec prereqs</li> 865 <li>Windows path canonicalization and document cache fix (Igor)</li> 866</ul> 867 868<h3>1.0.26: Feb 10 2003</h3> 869<ul> 870 <li>Fixed 3 serious bugs in document() and stylesheet compilation which 871 could lead to a crash</li> 872</ul> 873 874<h3>1.0.25: Feb 5 2003</h3> 875<ul> 876 <li>Bug fix: double-free for standalone stylesheets introduced in 1.0.24, C 877 syntax pbm, 3 bugs reported by Eric van der Vlist</li> 878 <li>Some XPath and XInclude related problems were actually fixed in 879 libxml2-2.5.2</li> 880 <li>Documentation: emphasize taht --docbook is not for XML docs.</li> 881</ul> 882 883<h3>1.0.24: Jan 14 2003</h3> 884<ul> 885 <li>bug fixes: imported global varables, python bindings (St�phane Bidoul), 886 EXSLT memory leak (Charles Bozeman), namespace generation on 887 xsl:attribute, space handling with imports (Daniel Stodden), 888 extension-element-prefixes (Josh Parsons), comments within xsl:text (Matt 889 Sergeant), superfluous xmlns generation, XInclude related bug for 890 numbering, EXSLT strings (Alexey Efimov), attribute-sets computation on 891 imports, extension module init and shutdown callbacks not called</li> 892 <li>HP-UX portability (Alexey Efimov), Windows makefiles (Igor and Stephane 893 Bidoul), VMS makefile updates (Craig A. Berry)</li> 894 <li>adds xsltGetProfileInformation() (Michael Rothwell)</li> 895 <li>fix the API generation scripts</li> 896 <li>API to provide the sorting routines (Richard Jinks)</li> 897 <li>added XML description of the EXSLT API</li> 898 <li>added ESXLT URI (un)escaping (J�rg Walter)</li> 899 <li>Some memory leaks have been found and fixed</li> 900 <li>document() now support fragment identifiers in URIs</li> 901</ul> 902 903<h3>1.0.23: Nov 17 2002</h3> 904<ul> 905 <li>Windows build cleanup (Igor)</li> 906 <li>Unix build and RPM packaging cleanup</li> 907 <li>Improvement of the python bindings: extension functions and activating 908 EXSLT</li> 909 <li>various bug fixes: number formatting, portability for bounded string 910 functions, CData nodes, key(), @*[...] patterns</li> 911 <li>Documentation improvements (John Fleck)</li> 912 <li>added libxslt.m4 (Thomas Schraitle)</li> 913</ul> 914 915<h3>1.0.22: Oct 18 2002</h3> 916<ul> 917 <li>Updates on the Windows Makefiles</li> 918 <li>Added a security module, and a related set of new options to 919 xsltproc</li> 920 <li>Allowed per transformation error handler.</li> 921 <li>Fixed a few bugs: node() semantic, URI escaping, media-type, attribute 922 lists</li> 923</ul> 924 925<h3>1.0.21: Sep 26 2002</h3> 926<ul> 927 <li>Bug fixes: match="node()", date:difference() (Igor and Charlie 928 Bozeman), disable-output-escaping</li> 929 <li>Python bindings: style.saveResultToString() from Ralf Mattes</li> 930 <li>Logos from Marc Liyanage</li> 931 <li>Mem leak fix from Nathan Myers</li> 932 <li>Makefile: DESTDIR fix from Christophe Merlet, AMD x86_64 (Mandrake), 933 Windows (Igor), Python detection</li> 934 <li>Documentation improvements: John Fleck</li> 935</ul> 936 937<h3>1.0.20: Aug 23 2002</h3> 938<ul> 939 <li>Windows makefile updates (Igor) and x86-64 (Frederic Crozat)</li> 940 <li>fixed HTML meta tag saving for Mac/IE users</li> 941 <li>possible leak patches from Nathan Myers</li> 942 <li>try to handle document('') as best as possible depending in the 943 cases</li> 944 <li>Fixed the DocBook stylesheets handling problem</li> 945 <li>Fixed a few XSLT reported errors</li> 946</ul> 947 948<h3>1.0.19: July 6 2002</h3> 949<ul> 950 <li>EXSLT: dynamic functions and date support bug fixes (Mark Vakoc)</li> 951 <li>xsl:number fix: Richard Jinks</li> 952 <li>xsl:format-numbers fix: Ken Neighbors</li> 953 <li>document('') fix: bug pointed by Eric van der Vlist</li> 954 <li>xsl:message with terminate="yes" fixes: William Brack</li> 955 <li>xsl:sort order support added: Ken Neighbors</li> 956 <li>a few other bug fixes, some of them requiring the latest version of 957 libxml2</li> 958</ul> 959 960<h3>1.0.18: May 27 2002</h3> 961<ul> 962 <li>a number of bug fixes: attributes, extra namespace declarations 963 (DocBook), xsl:include crash (Igor), documentation (Christian Cornelssen, 964 Charles Bozeman and Geert Kloosterman), element-available (Richard 965 Jinks)</li> 966 <li>xsltproc can now list teh registered extensions thanks to Mark 967 Vakoc</li> 968 <li>there is a new API to save directly to a string 969 xsltSaveResultToString() by Morus Walter</li> 970 <li>specific error registration function for the python API</li> 971</ul> 972 973<h3>1.0.17: April 29 2002</h3> 974<ul> 975 <li>cleanup in code, XSLT debugger support and Makefiles for Windows by 976 Igor</li> 977 <li>a C++ portability fix by Mark Vakoc</li> 978 <li>EXSLT date improvement and regression tests by Charles Bozeman</li> 979 <li>attempt to fix a bug in xsltProcessUserParamInternal</li> 980</ul> 981 982<h3>1.0.16: April 15 2002</h3> 983<ul> 984 <li>Bug fixes: strip-space, URL in HTML output, error when xsltproc can't 985 save</li> 986 <li>portability fixes: OSF/1, IEEE on alphas, Windows, Python bindings</li> 987</ul> 988 989<h3>1.0.15: Mar 25 2002</h3> 990<ul> 991 <li>Bugfixes: XPath, python Makefile, recursive attribute sets, @foo[..] 992 templates</li> 993 <li>Debug of memory alocation with valgind</li> 994 <li>serious profiling leading to significant improvement for DocBook 995 processing</li> 996 <li>revamp of the Windows build</li> 997</ul> 998 999<h3>1.0.14: Mar 18 2002</h3> 1000<ul> 1001 <li>Improvement in the XPath engine (libxml2-2.4.18)</li> 1002 <li>Nasty bug fix related to exslt:node-set</li> 1003 <li>Fixed the python Makefiles, cleanup of doc comments, Windows 1004 portability fixes</li> 1005</ul> 1006 1007<h3>1.0.13: Mar 8 2002</h3> 1008<ul> 1009 <li>a number of bug fixes including "namespace node have no parents"</li> 1010 <li>Improvement of the Python bindings</li> 1011 <li>Charles Bozeman provided fixes and regression tests for exslt date 1012 functions.</li> 1013</ul> 1014 1015<h3>1.0.12: Feb 11 2002</h3> 1016<ul> 1017 <li>Fixed the makefiles especially the python module ones</li> 1018 <li>half a dozen bugs fixes including 2 old ones</li> 1019</ul> 1020 1021<h3>1.0.11: Feb 8 2002</h3> 1022<ul> 1023 <li>Change of Licence to the <a 1024 href="http://www.opensource.org/licenses/mit-license.html">MIT 1025 Licence</a></li> 1026 <li>Added a beta version of the Python bindings, including support to 1027 extend the engine with functions written in Python</li> 1028 <li>A number of bug fixes</li> 1029 <li>Charlie Bozeman provided more EXSLT functions</li> 1030 <li>Portability fixes</li> 1031</ul> 1032 1033<h3>1.0.10: Jan 14 2002</h3> 1034<ul> 1035 <li>Windows fixes for Win32 from Igor</li> 1036 <li>Fixed the Solaris compilation trouble (Albert)</li> 1037 <li>Documentation changes and updates: John Fleck</li> 1038 <li>Added a stringparam option to avoid escaping hell at the shell 1039 level</li> 1040 <li>A few bug fixes</li> 1041</ul> 1042 1043<h3>1.0.9: Dec 7 2001</h3> 1044<ul> 1045 <li>Makefile patches from Peter Williams</li> 1046 <li>attempt to fix the compilation problem associated to prelinking</li> 1047 <li>obsoleted libxsltbreakpoint now deprecated and frozen to 1.0.8 API</li> 1048 <li>xsltproc return codes are now significant, John Fleck updated the 1049 documentation</li> 1050 <li>patch to allow as much as 40 steps in patterns (Marc Tardif), should be 1051 made dynamic really</li> 1052 <li>fixed a bug raised by Nik Clayton when using doctypes with HTML 1053 output</li> 1054 <li>patches from Keith Isdale to interface with xsltdebugger</li> 1055</ul> 1056 1057<h3>1.0.8: Nov 26 2001</h3> 1058<ul> 1059 <li>fixed an annoying header problem, removed a few bugs and some code 1060 cleanup</li> 1061 <li>patches for Windows and update of Windows Makefiles by Igor</li> 1062 <li>OpenVMS port instructions from John A Fotheringham</li> 1063 <li>fixed some Makefiles annoyance and libraries prelinking 1064 information</li> 1065</ul> 1066 1067<h3>1.0.7: Nov 10 2001</h3> 1068<ul> 1069 <li>remove a compilation problem with LIBXSLT_PUBLIC</li> 1070 <li>Finishing the integration steps for Keith Isdale debugger</li> 1071 <li>fixes the handling of indent="no" on HTML output</li> 1072 <li>fixes on the configure script and RPM spec file</li> 1073</ul> 1074 1075<h3>1.0.6: Oct 30 2001</h3> 1076<ul> 1077 <li>bug fixes on number formatting (Thomas), date/time functions (Bruce 1078 Miller)</li> 1079 <li>update of the Windows Makefiles (Igor)</li> 1080 <li>fixed DOCTYPE generation rules for HTML output (me)</li> 1081</ul> 1082 1083<h3>1.0.5: Oct 10 2001</h3> 1084<ul> 1085 <li>some portability fixes, including Windows makefile updates from 1086 Igor</li> 1087 <li>fixed a dozen bugs on XSLT and EXSLT (me and Thomas Broyer)</li> 1088 <li>support for Saxon's evaluate and expressions extensions added (initial 1089 contribution from Darren Graves)</li> 1090 <li>better handling of XPath evaluation errors</li> 1091</ul> 1092 1093<h3>1.0.4: Sep 12 2001</h3> 1094<ul> 1095 <li>Documentation updates from John fleck</li> 1096 <li>bug fixes (DocBook FO generation should be fixed) and portability 1097 improvements</li> 1098 <li>Thomas Broyer improved the existing EXSLT support and added String, 1099 Time and Date core functions support</li> 1100</ul> 1101 1102<h3>1.0.3: Aug 23 2001</h3> 1103<ul> 1104 <li>XML Catalog support see the doc</li> 1105 <li>New NaN/Infinity floating point code</li> 1106 <li>A few bug fixes</li> 1107</ul> 1108 1109<h3>1.0.2: Aug 15 2001</h3> 1110<ul> 1111 <li>lot of bug fixes, increased the testsuite</li> 1112 <li>a large chunk of EXSLT is implemented</li> 1113 <li>improvements on the extension framework</li> 1114 <li>documentation improvements</li> 1115 <li>Windows MSC projects files should be up-to-date</li> 1116 <li>handle attributes inherited from the DTD by default</li> 1117</ul> 1118 1119<h3>1.0.1: July 24 2001</h3> 1120<ul> 1121 <li>initial EXSLT framework</li> 1122 <li>better error reporting</li> 1123 <li>fixed the profiler on Windows</li> 1124 <li>bug fixes</li> 1125</ul> 1126 1127<h3>1.0.0: July 10 2001</h3> 1128<ul> 1129 <li>a lot of cleanup, a lot of regression tests added or fixed</li> 1130 <li>added a documentation for <a href="extensions.html">writing 1131 extensions</a></li> 1132 <li>fixed some variable evaluation problems (with William)</li> 1133 <li>added profiling of stylesheet execution accessible as the xsltproc 1134 --profile option</li> 1135 <li>fixed element-available() and the implementation of the various 1136 chunking methods present, Norm Walsh provided a lot of feedback</li> 1137 <li>exclude-result-prefixes and namespaces output should now work as 1138 expected</li> 1139 <li>added support of embedded stylesheet as described in section 2.7 of the 1140 spec</li> 1141</ul> 1142 1143<h3>0.14.0: July 5 2001</h3> 1144<ul> 1145 <li>lot of bug fixes, and code cleanup</li> 1146 <li>completion of the little XSLT-1.0 features left unimplemented</li> 1147 <li>Added and implemented the extension API suggested by Thomas Broyer</li> 1148 <li>the Windows MSC environment should be complete</li> 1149 <li>tested and optimized with a really large document (DocBook Definitive 1150 Guide) libxml/libxslt should really be faster on serious workloads</li> 1151</ul> 1152 1153<h3>0.13.0: June 26 2001</h3> 1154<ul> 1155 <li>lots of cleanups</li> 1156 <li>fixed a C++ compilation problem</li> 1157 <li>couple of fixes to xsltSaveTo()</li> 1158 <li>try to fix Docbook-xslt-1.4 and chunking, updated the regression test 1159 with them</li> 1160 <li>fixed pattern compilation and priorities problems</li> 1161 <li>Patches for Windows and MSC project mostly contributed by Yon Derek</li> 1162 <li>update to the Tutorial by John Fleck</li> 1163 <li>William fixed bugs in templates and for-each functions</li> 1164 <li>added a new interface xsltRunStylesheet() for a more flexible output 1165 (incomplete), added -o option to xsltproc</li> 1166</ul> 1167 1168<h3>0.12.0: June 18 2001</h3> 1169<ul> 1170 <li>fixed a dozen of bugs reported</li> 1171 <li>HTML generation should be quite better (requires libxml-2.3.11 upgrade 1172 too)</li> 1173 <li>William fixed some problems with document()</li> 1174 <li>Fix namespace nodes selection and copy (requires libxml-2.3.11 upgrade 1175 too)</li> 1176 <li>John Fleck added a<a href="tutorial/libxslttutorial.html"> 1177 tutorial</a></li> 1178 <li>Fixes for namespace handling when evaluating variables</li> 1179 <li>XInclude global flag added to process XInclude on document() if 1180 requested</li> 1181 <li>made xsltproc --version more detailed</li> 1182</ul> 1183 1184<h3>0.11.0: June 1 2001</h3> 1185 1186<p>Mostly a bug fix release.</p> 1187<ul> 1188 <li>integration of catalogs from xsltproc</li> 1189 <li>added --version to xsltproc for bug reporting</li> 1190 <li>fixed errors when handling ID in external parsed entities</li> 1191 <li>document() should hopefully work correctly but ...</li> 1192 <li>fixed bug with PI and comments processing</li> 1193 <li>William fixed the XPath string functions when using unicode</li> 1194</ul> 1195 1196<h3>0.10.0: May 19 2001</h3> 1197<ul> 1198 <li>cleanups to make stylesheet read-only (not 100% complete)</li> 1199 <li>fixed URI resolution in document()</li> 1200 <li>force all XPath expression to be compiled at stylesheet parsing time, 1201 even if unused ...</li> 1202 <li>Fixed HTML default output detection</li> 1203 <li>Fixed double attribute generation #54446</li> 1204 <li>Fixed {{ handling in attributes #54451</li> 1205 <li>More tests and speedups for DocBook document transformations</li> 1206 <li>Fixed a really bad race like bug in xsltCopyTreeList()</li> 1207 <li>added a documentation on the libxslt internals</li> 1208 <li>William Brack and Bjorn Reese improved format-number()</li> 1209 <li>Fixed multiple sort, it should really work now</li> 1210 <li>added a --docbook option for SGML DocBook input (hackish)</li> 1211 <li>a number of other bug fixes and regression test added as people were 1212 submitting them</li> 1213</ul> 1214 1215<h3>0.9.0: May 3 2001</h3> 1216<ul> 1217 <li>lot of various bugfixes, extended the regression suite</li> 1218 <li>xsltproc should work with multiple params</li> 1219 <li>added an option to use xsltproc with HTML input</li> 1220 <li>improved the stylesheet compilation, processing of complex stylesheets 1221 should be faster</li> 1222 <li>using the same stylesheet for concurrent processing on multithreaded 1223 programs should work now</li> 1224 <li>fixed another batch of namespace handling problems</li> 1225 <li>Implemented multiple level of sorting</li> 1226</ul> 1227 1228<h3>0.8.0: Apr 22 2001</h3> 1229<ul> 1230 <li>fixed ansidecl.h problem</li> 1231 <li>fixed unparsed-entity-uri() and generate-id()</li> 1232 <li>sort semantic fixes and priority prob from William M. Brack</li> 1233 <li>fixed namespace handling problems in XPath expression computations 1234 (requires libxml-2.3.7)</li> 1235 <li>fixes to current() and key()</li> 1236 <li>other, smaller fixes, lots of testing with N Walsh DocBook HTML 1237 stylesheets</li> 1238</ul> 1239 1240<h3>0.7.0: Apr 10 2001</h3> 1241<ul> 1242 <li>cleanup using stricter compiler flags</li> 1243 <li>command line parameter passing</li> 1244 <li>fix to xsltApplyTemplates from William M. Brack</li> 1245 <li>added the XSLTMark in the regression tests as well as document()</li> 1246</ul> 1247 1248<h3>0.6.0: Mar 22 2001</h3> 1249<ul> 1250 <li>another beta</li> 1251 <li>requires 2.3.5, which provide XPath expression compilation support</li> 1252 <li>document() extension should function properly</li> 1253 <li>fixed a number or reported bugs</li> 1254</ul> 1255 1256<h3>0.5.0: Mar 10 2001</h3> 1257<ul> 1258 <li>fifth beta</li> 1259 <li>some optimization work, for the moment 2 XSLT transform cannot use the 1260 same stylesheet at the same time (to be fixed)</li> 1261 <li>fixed problems with handling of tree results</li> 1262 <li>fixed a reported strip-spaces problem</li> 1263 <li>added more reported/fixed bugs to the test suite</li> 1264 <li>incorporated William M. Brack fix for imports and global variables as 1265 well as patch for with-param support in apply-templates</li> 1266 <li>a bug fix on for-each</li> 1267</ul> 1268 1269<h3>0.4.0: Mar 1 2001</h3> 1270<ul> 1271 <li>fourth beta test, released at the same time of libxml2-2.3.3</li> 1272 <li>bug fixes</li> 1273 <li>some optimization</li> 1274 <li>started implement extension support, not finished</li> 1275 <li>implemented but not tested multiple file output</li> 1276</ul> 1277 1278<h3>0.3.0: Feb 24 2001</h3> 1279<ul> 1280 <li>third beta test, released at the same time of libxml2-2.3.2</li> 1281 <li>lot of bug fixes</li> 1282 <li>some optimization</li> 1283 <li>added DocBook XSL based testsuite</li> 1284</ul> 1285 1286<h3>0.2.0: Feb 15 2001</h3> 1287<ul> 1288 <li>second beta version, released at the same time as libxml2-2.3.1</li> 1289 <li>getting close to feature completion, lot of bug fixes, some in the HTML 1290 and XPath support of libxml</li> 1291 <li>start becoming usable for real work. This version can now regenerate 1292 the XML 2e HTML from the original XML sources and the associated 1293 stylesheets (in <a 1294 href="http://www.w3.org/TR/REC-xml#b4d250b6c21">section I of the XML 1295 REC</a>)</li> 1296 <li>Still misses extension element/function/prefixes support. Support of 1297 key() and document() is not complete</li> 1298</ul> 1299 1300<h3>0.1.0: Feb 8 2001</h3> 1301<ul> 1302 <li>first beta version, released at the same time as libxml2-2.3.0</li> 1303 <li>lots of bug fixes, first "testing" version, but incomplete</li> 1304</ul> 1305 1306<h3>0.0.1: Jan 25 2001</h3> 1307<ul> 1308 <li>first alpha version released at the same time as libxml2-2.2.12</li> 1309 <li>Framework in place, should work on simple examples, but far from being 1310 feature complete</li> 1311</ul> 1312 1313<h2><a name="xsltproc">The xsltproc tool</a></h2> 1314 1315<p>This program is the simplest way to use libxslt: from the command line. It 1316is also used for doing the regression tests of the library.</p> 1317 1318<p>It takes as first argument the path or URL to an XSLT stylesheet, the next 1319arguments are filenames or URIs of the inputs to be processed. The output of 1320the processing is redirected on the standard output. There is actually a few 1321more options available:</p> 1322<pre>orchis:~ -> xsltproc 1323Usage: xsltproc [options] stylesheet file [file ...] 1324 Options: 1325 --version or -V: show the version of libxml and libxslt used 1326 --verbose or -v: show logs of what's happening 1327 --output file or -o file: save to a given file 1328 --timing: display the time used 1329 --repeat: run the transformation 20 times 1330 --debug: dump the tree of the result instead 1331 --novalid: skip the DTD loading phase 1332 --noout: do not dump the result 1333 --maxdepth val : increase the maximum depth 1334 --html: the input document is(are) an HTML file(s) 1335 --docbook: the input document is SGML docbook 1336 --param name value : pass a (parameter,value) pair 1337 --nonet refuse to fetch DTDs or entities over network 1338 --warnnet warn against fetching over the network 1339 --catalogs : use the catalogs from $SGML_CATALOG_FILES 1340 --xinclude : do XInclude processing on document input 1341 --profile or --norman : dump profiling information 1342orchis:~ -></pre> 1343 1344<h2><a name="DocBook">DocBook</a></h2> 1345 1346<p><img src="duck.png" align="right" alt="The duck picture"></p> 1347 1348<p><a href="http://www.oasis-open.org/committees/docbook/">DocBook</a> is an 1349XML/SGML vocabulary particularly well suited to books and papers about 1350computer hardware and software.</p> 1351 1352<p>xsltproc and libxslt are not specifically dependant on DocBook, but since 1353a lot of people use xsltproc and libxml2 for DocBook formatting, here are a 1354few pointers and information which may be helpful:</p> 1355<ul> 1356 <li>The <a href="http://www.oasis-open.org/committees/docbook/">DocBook 1357 homepage at Oasis</a> you should find pointers there on all the lastest 1358 versions of the DTDs and XSLT stylesheets</li> 1359 <li><a href="http://www.docbook.org/">DocBook: The Definitive Guide</a> is 1360 the official reference documentation for DocBook.</li> 1361 <li><a 1362 href="https://sourceforge.net/docman/index.php?group_id=21935">DocBook 1363 Open Repository</a> contains a lot of information about DocBook</li> 1364 <li>Bob Stayton provides a <a href="http://www.sagehill.net/">lot of 1365 resources</a> and consulting services around DocBook.</li> 1366 <li>Here is a <a href="/buildDocBookCatalog">shell script</a> to generate 1367 XML Catalogs for DocBook 4.1.2 . If it can write to the /etc/xml/ 1368 directory, it will set-up /etc/xml/catalog and /etc/xml/docbook based on 1369 the resources found on the system. Otherwise it will just create 1370 ~/xmlcatalog and ~/dbkxmlcatalog and doing: 1371 <p><code>export XMLCATALOG=$HOME/xmlcatalog</code></p> 1372 <p>should allow to process DocBook documentations without requiring 1373 network accesses for the DTd or stylesheets</p> 1374 </li> 1375 <li>I have uploaded <a href="ftp://xmlsoft.org/libxml2/test/dbk412catalog.tar.gz">a 1376 small tarball</a> containing XML Catalogs for DocBook 4.1.2 which seems 1377 to work fine for me too</li> 1378 <li>Informations on installing a <a 1379 href="http://wiki.docbook.org/topic/CygwinPackages">Windows 1380 DocBook processing setup</a> based on Cygwin (using the binaries from the 1381 official Windows port should be possible too)</li> 1382 <li>Alexander Kirillov's page on <a 1383 href="http://www.math.sunysb.edu/~kirillov/dbxml/">Using DocBook XML 1384 4.1.2</a> (RPM packages)</li> 1385 <li>Tim Waugh's <a href="http://cyberelk.net/tim/xmlto/">xmlto front-end 1386 conversion script</a></li> 1387 <li>Linux Documentation Project <a 1388 href="http://www.linuxdoc.org/HOWTO/mini/DocBook-Install/"> 1389 DocBook-Install-mini-HOWTO</a></li> 1390 <li>ScrollKeeper the open documentation cataloging project has a <a 1391 href="http://scrollkeeper.sourceforge.net/docbook.shtml">DocBook 1392 section</a></li> 1393 <li>Dan York presentation on <a 1394 href="http://www.lodestar2.com/people/dyork/talks/2001/xugo/docbook/index.html">Publishing 1395 using DocBook XML</a></li> 1396</ul> 1397 1398<p>Do not use the --docbook option of xsltproc to process XML DocBook 1399documents, this option is only intended to provide some (limited) support of 1400the SGML version of DocBook.</p> 1401 1402<p>Points which are not DocBook specific but still worth mentionning 1403again:</p> 1404<ul> 1405 <li>if you think DocBook processing time is too slow, make sure you have 1406 XML Catalogs pointing to a local installation of the DTD of DocBook. 1407 Check the <a href="http://xmlsoft.org/catalog.html">XML Catalog page</a> 1408 to understand more on this subject.</li> 1409 <li>before processing a new document, use the command 1410 <p><code>xmllint --valid --noout path_to_document</code></p> 1411 <p>to make sure that your input is valid DocBook. And fixes the errors 1412 before processing further. Note that XSLT processing may work correctly 1413 with some forms of validity errors left, but in general it can give 1414 troubles on output.</p> 1415 </li> 1416</ul> 1417 1418<h2><a name="API">The programming API</a></h2> 1419 1420<p>Okay this section is clearly incomplete. But integrating libxslt into your 1421application should be relatively easy. First check the few steps described 1422below, then for more detailed information, look at the<a 1423href="html/libxslt-lib.html"> generated pages</a> for the API and the source 1424of libxslt/xsltproc.c and the <a 1425href="tutorial/libxslttutorial.html">tutorial</a>.</p> 1426 1427<p>Basically doing an XSLT transformation can be done in a few steps:</p> 1428<ol> 1429 <li>configure the parser for XSLT: 1430 <p>xmlSubstituteEntitiesDefault(1);</p> 1431 <p>xmlLoadExtDtdDefaultValue = 1;</p> 1432 </li> 1433 <li>parse the stylesheet with xsltParseStylesheetFile()</li> 1434 <li>parse the document with xmlParseFile()</li> 1435 <li>apply the stylesheet using xsltApplyStylesheet()</li> 1436 <li>save the result using xsltSaveResultToFile() if needed set 1437 xmlIndentTreeOutput to 1</li> 1438</ol> 1439 1440<p>Steps 2,3, and 5 will probably need to be changed depending on you 1441processing needs and environment for example if reading/saving from/to 1442memory, or if you want to apply XInclude processing to the stylesheet or 1443input documents.</p> 1444 1445<h2><a name="Python">Python and bindings</a></h2> 1446 1447<p>There is a number of language bindings and wrappers available for libxml2, 1448the list below is not exhaustive. Please contact the <a 1449href="http://mail.gnome.org/mailman/listinfo/xml-bindings">xml-bindings@gnome.org</a> 1450(<a href="http://mail.gnome.org/archives/xml-bindings/">archives</a>) in 1451order to get updates to this list or to discuss the specific topic of libxml2 1452or libxslt wrappers or bindings:</p> 1453<ul> 1454 <li><a 1455 href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt 1456 Sergeant</a> developped <a href="http://axkit.org/download/">XML::LibXML 1457 and XML::LibXSLT</a>, Perl wrappers for libxml2/libxslt as part of the <a 1458 href="http://axkit.com/">AxKit XML application server</a></li> 1459 <li><a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a> provides and 1460 earlier version of the libxml/libxslt <a 1461 href="http://www.rexx.com/~dkuhlman">wrappers for Python</a></li> 1462 <li>Petr Kozelka provides <a 1463 href="http://sourceforge.net/projects/libxml2-pas">Pascal units to glue 1464 libxml2</a> with Kylix, Delphi and other Pascal compilers</li> 1465 <li>Wai-Sun "Squidster" Chia provides <a 1466 href="http://www.rubycolor.org/arc/redist/">bindings for Ruby</a> and 1467 libxml2 bindings are also available in Ruby through the <a 1468 href="http://libgdome-ruby.berlios.de/">libgdome-ruby</a> module 1469 maintained by Tobias Peters.</li> 1470 <li>Steve Ball and contributors maintains <a 1471 href="http://tclxml.sourceforge.net/">libxml2 and libxslt bindings for 1472 Tcl</a></li> 1473 <li><a href="mailto:xmlwrapp@pmade.org">Peter Jones</a> maintains C++ 1474 bindings for libxslt within <a 1475 href="http://pmade.org/pjones/software/xmlwrapp/">xmlwrapp</a></li> 1476 <li><a href="phillim2@comcast.net">Mike Phillips</a> provides a module 1477 using <a href="http://siasl.dyndns.org/projects/projects.html">libxslt 1478 for PHP</a>.</li> 1479 <li><a href="http://savannah.gnu.org/projects/classpathx/">LibxmlJ</a> is 1480 an effort to create a 100% JAXP-compatible Java wrapper for libxml2 and 1481 libxslt as part of GNU ClasspathX project.</li> 1482 <li>Patrick McPhee provides Rexx bindings fof libxml2 and libxslt, look for 1483 <a href="http://www.interlog.com/~ptjm/software.html">RexxXML</a>.</li> 1484 <li><a 1485 href="http://www.satimage.fr/software/en/xml_suite.html">Satimage</a> 1486 provides <a 1487 href="http://www.satimage.fr/software/en/downloads_osaxen.html">XMLLib 1488 osax</a>. This is an osax for Mac OS X with a set of commands to 1489 implement in AppleScript the XML DOM, XPATH and XSLT.</li> 1490</ul> 1491 1492<p>The libxslt Python module depends on the <a 1493href="http://xmlsoft.org/python.html">libxml2 Python</a> module.</p> 1494 1495<p>The distribution includes a set of Python bindings, which are guaranteed to 1496be maintained as part of the library in the future, though the Python 1497interface have not yet reached the completeness of the C API.</p> 1498 1499<p><a href="mailto:stephane.bidoul@softwareag.com">St�phane Bidoul</a> 1500maintains <a href="http://users.skynet.be/sbi/libxml-python/">a Windows port 1501of the Python bindings</a>.</p> 1502 1503<p>Note to people interested in building bindings, the API is formalized as 1504<a href="libxslt-api.xml">an XML API description file</a> which allows to 1505automate a large part of the Python bindings, this includes function 1506descriptions, enums, structures, typedefs, etc... The Python script used to 1507build the bindings is python/generator.py in the source distribution.</p> 1508 1509<p>To install the Python bindings there are 2 options:</p> 1510<ul> 1511 <li>If you use an RPM based distribution, simply install the <a 1512 href="http://rpmfind.net/linux/rpm2html/search.php?query=libxml2-python">libxml2-python 1513 RPM</a> and the <a 1514 href="http://rpmfind.net/linux/rpm2html/search.php?query=libxslt-python">libxslt-python 1515 RPM</a>.</li> 1516 <li>Otherwise use the <a href="ftp://xmlsoft.org/libxml2/python/">libxml2-python 1517 module distribution</a> corresponding to your installed version of 1518 libxml2 and libxslt. Note that to install it you will need both libxml2 1519 and libxslt installed and run "python setup.py build install" in the 1520 module tree.</li> 1521</ul> 1522 1523<p>The distribution includes a set of examples and regression tests for the 1524python bindings in the <code>python/tests</code> directory. Here are some 1525excepts from those tests:</p> 1526 1527<h3>basic.py:</h3> 1528 1529<p>This is a basic test of XSLT interfaces: loading a stylesheet and a 1530document, transforming the document and saving the result.</p> 1531<pre>import libxml2 1532import libxslt 1533 1534styledoc = libxml2.parseFile("test.xsl") 1535style = libxslt.parseStylesheetDoc(styledoc) 1536doc = libxml2.parseFile("test.xml") 1537result = style.applyStylesheet(doc, None) 1538style.saveResultToFilename("foo", result, 0) 1539style.freeStylesheet() 1540doc.freeDoc() 1541result.freeDoc()</pre> 1542 1543<p>The Python module is called libxslt, you will also need the libxml2 module 1544for the operations on XML trees. Let's have a look at the objects manipulated 1545in that example and how is the processing done:</p> 1546<ul> 1547 <li><code>styledoc</code> : is a libxml2 document tree. It is obtained by 1548 parsing the XML file "test.xsl" containing the stylesheet.</li> 1549 <li><code>style</code> : this is a precompiled stylesheet ready to be used 1550 by the following transformations (note the plural form, multiple 1551 transformations can resuse the same stylesheet).</li> 1552 <li><code>doc</code> : this is the document to apply the transformation to. 1553 In this case it is simply generated by parsing it from a file but any 1554 other processing is possible as long as one get a libxml2 Doc. Note that 1555 HTML tree are suitable for XSLT processing in libxslt. This is actually 1556 how this page is generated !</li> 1557 <li><code>result</code> : this is a document generated by applying the 1558 stylesheet to the document. Note that some of the stylesheet information 1559 may be related to the serialization of that document and as in this 1560 example a specific saveResultToFilename() method of the stylesheet should 1561 be used to save it to a file (in that case to "foo").</li> 1562</ul> 1563 1564<p>Also note the need to explicitely deallocate documents with freeDoc() 1565except for the stylesheet document which is freed when its compiled form is 1566garbage collected.</p> 1567 1568<h3>extfunc.py:</h3> 1569 1570<p>This one is a far more complex test. It shows how to modify the behaviour 1571of an XSLT transformation by passing parameters and how to extend the XSLT 1572engine with functions defined in python:</p> 1573<pre>import libxml2 1574import libxslt 1575import string 1576 1577nodeName = None 1578def f(ctx, str): 1579 global nodeName 1580 1581 # 1582 # Small check to verify the context is correcly accessed 1583 # 1584 try: 1585 pctxt = libxslt.xpathParserContext(_obj=ctx) 1586 ctxt = pctxt.context() 1587 tctxt = ctxt.transformContext() 1588 nodeName = tctxt.insertNode().name 1589 except: 1590 pass 1591 1592 return string.upper(str) 1593 1594libxslt.registerExtModuleFunction("foo", "http://example.com/foo", f)</pre> 1595 1596<p>This code defines and register an extension function. Note that the 1597function can be bound to any name (foo) and how the binding is also 1598associated to a namespace name "http://example.com/foo". From an XSLT point 1599of view the function just returns an upper case version of the string passed 1600as a parameter. But the first part of the function also read some contextual 1601information from the current XSLT processing environement, in that case it 1602looks for the current insertion node in the resulting output (either the 1603resulting document or the Result Value Tree being generated), and saves it to 1604a global variable for checking that the access actually worked.</p> 1605 1606<p>For more information on the xpathParserContext and transformContext 1607objects check the <a href="internals.html">libray internals description</a>. 1608The pctxt is actually an object from a class derived from the 1609libxml2.xpathParserContext() with just a couple more properties including the 1610possibility to look up the XSLT transformation context from the XPath 1611context.</p> 1612<pre>styledoc = libxml2.parseDoc(""" 1613<xsl:stylesheet version='1.0' 1614 xmlns:xsl='http://www.w3.org/1999/XSL/Transform' 1615 xmlns:foo='http://example.com/foo' 1616 xsl:exclude-result-prefixes='foo'> 1617 1618 <xsl:param name='bar'>failure</xsl:param> 1619 <xsl:template match='/'> 1620 <article><xsl:value-of select='foo:foo($bar)'/></article> 1621 </xsl:template> 1622</xsl:stylesheet> 1623""")</pre> 1624 1625<p>Here is a simple example of how to read an XML document from a python 1626string with libxml2. Note how this stylesheet:</p> 1627<ul> 1628 <li>Uses a global parameter <code>bar</code></li> 1629 <li>Reference the extension function f</li> 1630 <li>how the Namespace name "http://example.com/foo" has to be bound to a 1631 prefix</li> 1632 <li>how that prefix is excluded from the output</li> 1633 <li>how the function is called from the select</li> 1634</ul> 1635<pre>style = libxslt.parseStylesheetDoc(styledoc) 1636doc = libxml2.parseDoc("<doc/>") 1637result = style.applyStylesheet(doc, { "bar": "'success'" }) 1638style.freeStylesheet() 1639doc.freeDoc()</pre> 1640 1641<p>that part is identical, to the basic example except that the 1642transformation is passed a dictionary of parameters. Note that the string 1643passed "success" had to be quoted, otherwise it is interpreted as an XPath 1644query for the childs of root named "success".</p> 1645<pre>root = result.children 1646if root.name != "article": 1647 print "Unexpected root node name" 1648 sys.exit(1) 1649if root.content != "SUCCESS": 1650 print "Unexpected root node content, extension function failed" 1651 sys.exit(1) 1652if nodeName != 'article': 1653 print "The function callback failed to access its context" 1654 sys.exit(1) 1655 1656result.freeDoc()</pre> 1657 1658<p>That part just verifies that the transformation worked, that the parameter 1659got properly passed to the engine, that the function f() got called and that 1660it properly accessed the context to find the name of the insertion node.</p> 1661 1662<h3>pyxsltproc.py:</h3> 1663 1664<p>this module is a bit too long to be described there but it is basically a 1665rewrite of the xsltproc command line interface of libxslt in Python. It 1666provides nearly all the functionalities of xsltproc and can be used as a base 1667module to write Python customized XSLT processors. One of the thing to notice 1668are:</p> 1669<pre>libxml2.lineNumbersDefault(1) 1670libxml2.substituteEntitiesDefault(1)</pre> 1671 1672<p>those two calls in the main() function are needed to force the libxml2 1673processor to generate DOM trees compliant with the XPath data model.</p> 1674 1675<h2><a name="Internals">Library internals</a></h2> 1676 1677<h3>Table of contents</h3> 1678<ul> 1679 <li><a href="internals.html#Introducti">Introduction</a></li> 1680 <li><a href="internals.html#Basics">Basics</a></li> 1681 <li><a href="internals.html#Keep">Keep it simple stupid</a></li> 1682 <li><a href="internals.html#libxml">The libxml nodes</a></li> 1683 <li><a href="internals.html#XSLT">The XSLT processing steps</a></li> 1684 <li><a href="internals.html#XSLT1">The XSLT stylesheet compilation</a></li> 1685 <li><a href="internals.html#XSLT2">The XSLT template compilation</a></li> 1686 <li><a href="internals.html#processing">The processing itself</a></li> 1687 <li><a href="internals.html#XPath">XPath expressions compilation</a></li> 1688 <li><a href="internals.html#XPath1">XPath interpretation</a></li> 1689 <li><a href="internals.html#Descriptio">Description of XPath 1690 Objects</a></li> 1691 <li><a href="internals.html#XPath3">XPath functions</a></li> 1692 <li><a href="internals.html#stack">The variables stack frame</a></li> 1693 <li><a href="internals.html#Extension">Extension support</a></li> 1694 <li><a href="internals.html#Futher">Further reading</a></li> 1695 <li><a href="internals.html#TODOs">TODOs</a></li> 1696 <li><a href="internals.html#Thanks">Thanks</a></li> 1697</ul> 1698 1699<h3><a name="Introducti2">Introduction</a></h3> 1700 1701<p>This document describes the processing of <a 1702href="http://xmlsoft.org/XSLT/">libxslt</a>, the <a 1703href="http://www.w3.org/TR/xslt">XSLT</a> C library developed for the <a 1704href="http://www.gnome.org/">GNOME</a> project.</p> 1705 1706<p>Note: this documentation is by definition incomplete and I am not good at 1707spelling, grammar, so patches and suggestions are <a 1708href="mailto:veillard@redhat.com">really welcome</a>.</p> 1709 1710<h3><a name="Basics1">Basics</a></h3> 1711 1712<p>XSLT is a transformation language. It takes an input document and a 1713stylesheet document and generates an output document:</p> 1714 1715<p align="center"><img src="processing.gif" 1716alt="the XSLT processing model"></p> 1717 1718<p>Libxslt is written in C. It relies on <a 1719href="http://www.xmlsoft.org/">libxml</a>, the XML C library for GNOME, for 1720the following operations:</p> 1721<ul> 1722 <li>parsing files</li> 1723 <li>building the in-memory DOM structure associated with the documents 1724 handled</li> 1725 <li>the XPath implementation</li> 1726 <li>serializing back the result document to XML and HTML. (Text is handled 1727 directly.)</li> 1728</ul> 1729 1730<h3><a name="Keep1">Keep it simple stupid</a></h3> 1731 1732<p>Libxslt is not very specialized. It is built under the assumption that all 1733nodes from the source and output document can fit in the virtual memory of 1734the system. There is a big trade-off there. It is fine for reasonably sized 1735documents but may not be suitable for large sets of data. The gain is that it 1736can be used in a relatively versatile way. The input or output may never be 1737serialized, but the size of documents it can handle are limited by the size 1738of the memory available.</p> 1739 1740<p>More specialized memory handling approaches are possible, like building 1741the input tree from a serialization progressively as it is consumed, 1742factoring repetitive patterns, or even on-the-fly generation of the output as 1743the input is parsed but it is possible only for a limited subset of the 1744stylesheets. In general the implementation of libxslt follows the following 1745pattern:</p> 1746<ul> 1747 <li>KISS (keep it simple stupid)</li> 1748 <li>when there is a clear bottleneck optimize on top of this simple 1749 framework and refine only as much as is needed to reach the expected 1750 result</li> 1751</ul> 1752 1753<p>The result is not that bad, clearly one can do a better job but more 1754specialized too. Most optimization like building the tree on-demand would 1755need serious changes to the libxml XPath framework. An easy step would be to 1756serialize the output directly (or call a set of SAX-like output handler to 1757keep this a flexible interface) and hence avoid the memory consumption of the 1758result.</p> 1759 1760<h3><a name="libxml">The libxml nodes</a></h3> 1761 1762<p>DOM-like trees, as used and generated by libxml and libxslt, are 1763relatively complex. Most node types follow the given structure except a few 1764variations depending on the node type:</p> 1765 1766<p align="center"><img src="node.gif" alt="description of a libxml node"></p> 1767 1768<p>Nodes carry a <strong>name</strong> and the node <strong>type</strong> 1769indicates the kind of node it represents, the most common ones are:</p> 1770<ul> 1771 <li>document nodes</li> 1772 <li>element nodes</li> 1773 <li>text nodes</li> 1774</ul> 1775 1776<p>For the XSLT processing, entity nodes should not be generated (i.e. they 1777should be replaced by their content). Most nodes also contains the following 1778"navigation" information:</p> 1779<ul> 1780 <li>the containing <strong>doc</strong>ument</li> 1781 <li>the <strong>parent</strong> node</li> 1782 <li>the first <strong>children</strong> node</li> 1783 <li>the <strong>last</strong> children node</li> 1784 <li>the <strong>prev</strong>ious sibling</li> 1785 <li>the following sibling (<strong>next</strong>)</li> 1786</ul> 1787 1788<p>Elements nodes carries the list of attributes in the properties, an 1789attribute itself holds the navigation pointers and the children list (the 1790attribute value is not represented as a simple string to allow usage of 1791entities references).</p> 1792 1793<p>The <strong>ns</strong> points to the namespace declaration for the 1794namespace associated to the node, <strong>nsDef</strong> is the linked list 1795of namespace declaration present on element nodes.</p> 1796 1797<p>Most nodes also carry an <strong>_private</strong> pointer which can be 1798used by the application to hold specific data on this node.</p> 1799 1800<h3><a name="XSLT">The XSLT processing steps</a></h3> 1801 1802<p>There are a few steps which are clearly decoupled at the interface 1803level:</p> 1804<ol> 1805 <li>parse the stylesheet and generate a DOM tree</li> 1806 <li>take the stylesheet tree and build a compiled version of it (the 1807 compilation phase)</li> 1808 <li>take the input and generate a DOM tree</li> 1809 <li>process the stylesheet against the input tree and generate an output 1810 tree</li> 1811 <li>serialize the output tree</li> 1812</ol> 1813 1814<p>A few things should be noted here:</p> 1815<ul> 1816 <li>the steps 1/ 3/ and 5/ are optional: the DOM representing the 1817 stylesheet and input can be created by other means, not just by parsing 1818 serialized XML documents, and similarly the result tree DOM can be 1819 made available to other processeswithout being serialized. 1820 <li>the stylesheet obtained at 2/ can be reused by multiple processing 4/ 1821 (and this should also work in threaded programs)</li> 1822 <li>the tree provided in 2/ should never be freed using xmlFreeDoc, but by 1823 freeing the stylesheet.</li> 1824 <li>the input tree created in step 3/ is not modified except the 1825 _private field which may be used for labelling keys if used by the 1826 stylesheet. It's not modified at all in step 4/ to allow parallel 1827 processing using a shared precompiled stylesheet.</li> 1828</ul> 1829 1830<h3><a name="XSLT1">The XSLT stylesheet compilation</a></h3> 1831 1832<p>This is the second step described. It takes a stylesheet tree, and 1833"compiles" it. This associates to each node a structure stored in the 1834_private field and containing information computed in the stylesheet:</p> 1835 1836<p align="center"><img src="stylesheet.gif" 1837alt="a compiled XSLT stylesheet"></p> 1838 1839<p>One xsltStylesheet structure is generated per document parsed for the 1840stylesheet. XSLT documents allow includes and imports of other documents, 1841imports are stored in the <strong>imports</strong> list (hence keeping the 1842tree hierarchy of includes which is very important for a proper XSLT 1843processing model) and includes are stored in the <strong>doclist</strong> 1844list. An imported stylesheet has a parent link to allow browsing of the 1845tree.</p> 1846 1847<p>The DOM tree associated to the document is stored in <strong>doc</strong>. 1848It is preprocessed to remove ignorable empty nodes and all the nodes in the 1849XSLT namespace are subject to precomputing. This usually consist of 1850extracting all the context information from the context tree (attributes, 1851namespaces, XPath expressions), and storing them in an xsltStylePreComp 1852structure associated to the <strong>_private</strong> field of the node.</p> 1853 1854<p>A couple of notable exceptions to this are XSLT template nodes (more on 1855this later) and attribute value templates. If they are actually templates, 1856the value cannot be computed at compilation time. (Some preprocessing could 1857be done like isolation and preparsing of the XPath subexpressions but it's 1858not done, yet.)</p> 1859 1860<p>The xsltStylePreComp structure also allows storing of the precompiled form 1861of an XPath expression that can be associated to an XSLT element (more on 1862this later).</p> 1863 1864<h3><a name="XSLT2">The XSLT template compilation</a></h3> 1865 1866<p>A proper handling of templates lookup is one of the keys of fast XSLT 1867processing. (Given a node in the source document this is the process of 1868finding which templates should be applied to this node.) Libxslt follows the 1869hint suggested in the <a href="http://www.w3.org/TR/xslt#patterns">5.2 1870Patterns</a> section of the XSLT Recommendation, i.e. it doesn't evaluate it 1871as an XPath expression but tokenizes it and compiles it as a set of rules to 1872be evaluated on a candidate node. There usually is an indication of the node 1873name in the last step of this evaluation and this is used as a key check for 1874the match. As a result libxslt builds a relatively more complex set of 1875structures for the templates:</p> 1876 1877<p align="center"><img src="templates.gif" 1878alt="The templates related structure"></p> 1879 1880<p>Let's describe a bit more closely what is built. First the xsltStylesheet 1881structure holds a pointer to the template hash table. All the XSLT patterns 1882compiled in this stylesheet are indexed by the value of the the target 1883element (or attribute, pi ...) name, so when a element or an attribute "foo" 1884needs to be processed the lookup is done using the name as a key.</p> 1885 1886<p>Each of the patterns is compiled into an xsltCompMatch 1887(i.e. an ''XSLT compiled match') structure. It holds 1888the set of rules based on the tokenization of the pattern stored in reverse 1889order (matching is easier this way). </p> 1890 1891<p>The xsltCompMatch are then stored in the hash table, the clash list is 1892itself sorted by priority of the template to implement "naturally" the XSLT 1893priority rules.</p> 1894 1895<p>Associated to the compiled pattern is the xsltTemplate itself containing 1896the information required for the processing of the pattern including, of 1897course, a pointer to the list of elements used for building the pattern 1898result.</p> 1899 1900<p>Last but not least a number of patterns do not fit in the hash table 1901because they are not associated to a name, this is the case for patterns 1902applying to the root, any element, any attributes, text nodes, pi nodes, keys 1903etc. Those are stored independently in the stylesheet structure as separate 1904linked lists of xsltCompMatch.</p> 1905 1906<h3><a name="processing">The processing itself</a></h3> 1907 1908<p>The processing is defined by the XSLT specification (the basis of the 1909algorithm is explained in <a 1910href="http://www.w3.org/TR/xslt#section-Introduction">the Introduction</a> 1911section). Basically it works by taking the root of the input document 1912as the cureent node and applying the following algorithm:</p> 1913<ol> 1914 <li>Finding the template applying to current node. 1915 This is a lookup in the template hash table, walking the hash list until 1916 the node satisfies all the steps of the pattern, then checking the 1917 appropriate global template(s) (i.e. templates applying to a node type) 1918 to see if there isn't a higher priority rule to apply</li> 1919 <li>If there is no template, apply the default rule (recurse on the 1920 children as the current node)</li> 1921 <li>else walk the content list of the selected templates, for each of them: 1922 <ul> 1923 <li>if the node is in the XSLT namespace then the node has a _private 1924 field pointing to the preprocessed values, jump to the specific 1925 code</li> 1926 <li>if the node is in an extension namespace, look up the associated 1927 behavior</li> 1928 <li>otherwise copy the node.</li> 1929 </ul> 1930 <p>The closure is usually done through the XSLT 1931 <strong>apply-templates</strong>construct, which invokes this process 1932 recursively starting at step 1, to find the appropriate template 1933 for the nodes selected by the 'select' attribute of the apply-templates 1934 instruction (default: the children of the node currently being 1935 processed)</p> 1936 </li> 1937</ol> 1938 1939<p>Note that large parts of the input tree may not be processed by a given 1940stylesheet and that conversely some may be processed multiple times. 1941(This often is the case when a Table of Contents is built).</p> 1942 1943<p>The module <code>transform.c</code> is the one implementing most of this 1944logic. <strong>xsltApplyStylesheet()</strong> is the entry point, it 1945allocates an xsltTransformContext containing the following:</p> 1946<ul> 1947 <li>a pointer to the stylesheet being processed</li> 1948 <li>a stack of templates</li> 1949 <li>a stack of variables and parameters</li> 1950 <li>an XPath context</li> 1951 <li>the template mode</li> 1952 <li>current document</li> 1953 <li>current input node</li> 1954 <li>current selected node list</li> 1955 <li>the current insertion points in the output document</li> 1956 <li>a couple of hash tables for extension elements and functions</li> 1957</ul> 1958 1959<p>Then a new document gets allocated (HTML or XML depending on the type of 1960output), the user parameters and global variables and parameters are 1961evaluated. Then <strong>xsltProcessOneNode()</strong> which implements the 19621-2-3 algorithm is called on the docuemnt node of the input. Step 1/ is 1963implemented by calling <strong>xsltGetTemplate()</strong>, step 2/ is 1964implemented by <strong>xsltDefaultProcessOneNode()</strong> and step 3/ is 1965implemented by <strong>xsltApplyOneTemplate()</strong>.</p> 1966 1967<h3><a name="XPath">XPath expression compilation</a></h3> 1968 1969<p>The XPath support is actually implemented in the libxml module (where it 1970is reused by the XPointer implementation). XPath is a relatively classic 1971expression language. The only uncommon feature is that it is working on XML 1972trees and hence has specific syntax and types to handle them.</p> 1973 1974<p>XPath expressions are compiled using <strong>xmlXPathCompile()</strong>. 1975It will take an expression string in input and generate a structure 1976containing the parsed expression tree, for example the expression:</p> 1977<pre>/doc/chapter[title='Introduction']</pre> 1978 1979<p>will be compiled as</p> 1980<pre>Compiled Expression : 10 elements 1981 SORT 1982 COLLECT 'child' 'name' 'node' chapter 1983 COLLECT 'child' 'name' 'node' doc 1984 ROOT 1985 PREDICATE 1986 SORT 1987 EQUAL = 1988 COLLECT 'child' 'name' 'node' title 1989 NODE 1990 ELEM Object is a string : Introduction 1991 COLLECT 'child' 'name' 'node' title 1992 NODE</pre> 1993 1994<p>This can be tested using the <code>testXPath</code> command (in the 1995libxml codebase) using the <code>--tree</code> option.</p> 1996 1997<p>Again, the KISS approach is used. No optimization is done. This could be 1998an interesting thing to add. <a 1999href="http://www-106.ibm.com/developerworks/library/x-xslt2/?dwzone=x?open&l=132%2ct=gr%2c+p=saxon">Michael 2000Kay describes</a> a lot of possible and interesting optimizations done in 2001Saxon which would be possible at this level. I'm unsure they would provide 2002much gain since the expressions tends to be relatively simple in general and 2003stylesheets are still hand generated. Optimizations at the interpretation 2004sounds likely to be more efficient.</p> 2005 2006<h3><a name="XPath1">XPath interpretation</a></h3> 2007 2008<p>The interpreter is implemented by <strong>xmlXPathCompiledEval()</strong> 2009which is the front-end to <strong>xmlXPathCompOpEval()</strong> the function 2010implementing the evaluation of the expression tree. This evaluation follows 2011the KISS approach again. It's recursive and calls 2012<strong>xmlXPathNodeCollectAndTest()</strong> to collect a set of nodes when 2013evaluating a <code>COLLECT</code> node.</p> 2014 2015<p>An evaluation is done within the framework of an XPath context stored in 2016an <strong>xmlXPathContext</strong> structure, in the framework of a 2017transformation the context is maintained within the XSLT context. Its content 2018follows the requirements from the XPath specification:</p> 2019<ul> 2020 <li>the current document</li> 2021 <li>the current node</li> 2022 <li>a hash table of defined variables (but not used by XSLT, 2023 which uses its own stack frame for variables, described below)</li> 2024 <li>a hash table of defined functions</li> 2025 <li>the proximity position (the place of the node in the current node 2026 list)</li> 2027 <li>the context size (the size of the current node list)</li> 2028 <li>the array of namespace declarations in scope (there also is a namespace 2029 hash table but it is not used in the XSLT transformation).</li> 2030</ul> 2031 2032<p>For the purpose of XSLT an <strong>extra</strong> pointer has been added 2033allowing to retrieve the XSLT transformation context. When an XPath 2034evaluation is about to be performed, an XPath parser context is allocated 2035containing an XPath object stack (this is actually an XPath evaluation 2036context, this is a relic of the time where there was no separate parsing and 2037evaluation phase in the XPath implementation). Here is an overview of the set 2038of contexts associated to an XPath evaluation within an XSLT 2039transformation:</p> 2040 2041<p align="center"><img src="contexts.gif" 2042alt="The set of contexts associated "></p> 2043 2044<p>Clearly this is a bit too complex and confusing and should be refactored 2045at the next set of binary incompatible releases of libxml. For example the 2046xmlXPathCtxt has a lot of unused parts and should probably be merged with 2047xmlXPathParserCtxt.</p> 2048 2049<h3><a name="Descriptio">Description of XPath Objects</a></h3> 2050 2051<p>An XPath expression manipulates XPath objects. XPath defines the default 2052types boolean, numbers, strings and node sets. XSLT adds the result tree 2053fragment type which is basically an unmodifiable node set.</p> 2054 2055<p>Implementation-wise, libxml follows again a KISS approach, the 2056xmlXPathObject is a structure containing a type description and the various 2057possibilities. (Using an enum could have gained some bytes.) In the case of 2058node sets (or result tree fragments), it points to a separate xmlNodeSet 2059object which contains the list of pointers to the document nodes:</p> 2060 2061<p align="center"><img src="object.gif" 2062alt="An Node set object pointing to "></p> 2063 2064<p>The <a href="http://xmlsoft.org/html/libxml-xpath.html">XPath API</a> (and 2065its <a href="http://xmlsoft.org/html/libxml-xpathinternals.html">'internal' 2066part</a>) includes a number of functions to create, copy, compare, convert or 2067free XPath objects.</p> 2068 2069<h3><a name="XPath3">XPath functions</a></h3> 2070 2071<p>All the XPath functions available to the interpreter are registered in the 2072function hash table linked from the XPath context. They all share the same 2073signature:</p> 2074<pre>void xmlXPathFunc (xmlXPathParserContextPtr ctxt, int nargs);</pre> 2075 2076<p>The first argument is the XPath interpretation context, holding the 2077interpretation stack. The second argument defines the number of objects 2078passed on the stack for the function to consume (last argument is on top of 2079the stack).</p> 2080 2081<p>Basically an XPath function does the following:</p> 2082<ul> 2083 <li>check <code>nargs</code> for proper handling of errors or functions 2084 with variable numbers of parameters</li> 2085 <li>pop the parameters from the stack using <code>obj = 2086 valuePop(ctxt);</code></li> 2087 <li>do the function specific computation</li> 2088 <li>push the result parameter on the stack using <code>valuePush(ctxt, 2089 res);</code></li> 2090 <li>free up the input parameters with 2091 <code>xmlXPathFreeObject(obj);</code></li> 2092 <li>return</li> 2093</ul> 2094 2095<p>Sometime the work can be done directly by modifying in-situ the top object 2096on the stack <code>ctxt->value</code>.</p> 2097 2098<h3><a name="stack">The XSLT variables stack frame</a></h3> 2099 2100<p>Not to be confused with XPath object stack, this stack holds the XSLT 2101variables and parameters as they are defined through the recursive calls of 2102call-template, apply-templates and default templates. This is used to define 2103the scope of variables being called.</p> 2104 2105<p>This part seems to be one needing most work , first it is 2106done in a very inefficient way since the location of the variables and 2107parameters within the stylesheet tree is still done at run time (it really 2108should be done statically at compile time), and I am still unsure that my 2109understanding of the template variables and parameter scope is actually 2110right.</p> 2111 2112<p>This part of the documentation is still to be written once this part of 2113the code will be stable. <span 2114style="background-color: #FF0000">TODO</span></p> 2115 2116<h3><a name="Extension">Extension support</a></h3> 2117 2118<p>There is a separate document explaining <a href="extensions.html">how the 2119extension support works</a>.</p> 2120 2121<h3><a name="Futher">Further reading</a></h3> 2122 2123<p>Michael Kay wrote <a 2124href="http://www-106.ibm.com/developerworks/library/x-xslt2/?dwzone=x?open&l=132%2ct=gr%2c+p=saxon">a 2125really interesting article on Saxon internals</a> and the work he did on 2126performance issues. I wish I had read it before starting libxslt design (I 2127would probably have avoided a few mistakes and progressed faster). A lot of 2128the ideas in his papers should be implemented or at least tried in 2129libxslt.</p> 2130 2131<p>The <a href="http://xmlsoft.org/">libxml documentation</a>, especially <a 2132href="http://xmlsoft.org/xmlio.html">the I/O interfaces</a> and the <a 2133href="http://xmlsoft.org/xmlmem.html">memory management</a>.</p> 2134 2135<h3><a name="TODOs">TODOs</a></h3> 2136 2137<p>redesign the XSLT stack frame handling. Far too much work is done at 2138execution time. Similarly for the attribute value templates handling, at 2139least the embedded subexpressions ought to be precompiled.</p> 2140 2141<p>Allow output to be saved to a SAX like output (this notion of SAX like API 2142for output should be added directly to libxml).</p> 2143 2144<p>Implement and test some of the optimization explained by Michael Kay 2145especially:</p> 2146<ul> 2147 <li>static slot allocation on the stack frame</li> 2148 <li>specific boolean interpretation of an XPath expression</li> 2149 <li>some of the sorting optimization</li> 2150 <li>Lazy evaluation of location path. (this may require more changes but 2151 sounds really interesting. XT does this too.)</li> 2152 <li>Optimization of an expression tree (This could be done as a completely 2153 independent module.)</li> 2154</ul> 2155 2156<p></p> 2157 2158<p>Error reporting, there is a lot of case where the XSLT specification 2159specify that a given construct is an error are not checked adequately by 2160libxslt. Basically one should do a complete pass on the XSLT spec again and 2161add all tests to the stylesheet compilation. Using the DTD provided in the 2162appendix and making direct checks using the libxml validation API sounds a 2163good idea too (though one should take care of not raising errors for 2164elements/attributes in different namespaces).</p> 2165 2166<p>Double check all the places where the stylesheet compiled form might be 2167modified at run time (extra removal of blanks nodes, hint on the 2168xsltCompMatch).</p> 2169 2170<h3><a name="Thanks">Thanks:</a></h3> 2171<p>Thanks to <a href="http://cmsmcq.com/">Michael Sperberg-McQueen</a> for 2172 various fixes and clarifications on this document!</p> 2173 2174<p></p> 2175 2176<h2><a name="Extensions">Writing extensions</a></h2> 2177 2178<h3>Table of content</h3> 2179<ul> 2180 <li><a href="extensions.html#Introducti">Introduction</a></li> 2181 <li><a href="extensions.html#Basics">Basics</a></li> 2182 <li><a href="extensions.html#Keep">Extension modules</a></li> 2183 <li><a href="extensions.html#Registerin">Registering a module</a></li> 2184 <li><a href="extensions.html#module">Loading a module</a></li> 2185 <li><a href="extensions.html#Registerin1">Registering an extension 2186 function</a></li> 2187 <li><a href="extensions.html#Implementi">Implementing an extension 2188 function</a></li> 2189 <li><a href="extensions.html#Examples">Examples for extension 2190 functions</a></li> 2191 <li><a href="extensions.html#Registerin2">Registering an extension 2192 element</a></li> 2193 <li><a href="extensions.html#Implementi1">Implementing an extension 2194 element</a></li> 2195 <li><a href="extensions.html#Example">Example for extension 2196 elements</a></li> 2197 <li><a href="extensions.html#shutdown">The shutdown of a module</a></li> 2198 <li><a href="extensions.html#Future">Future work</a></li> 2199</ul> 2200 2201<h3><a name="Introducti1">Introduction</a></h3> 2202 2203<p>This document describes the work needed to write extensions to the 2204standard XSLT library for use with <a 2205href="http://xmlsoft.org/XSLT/">libxslt</a>, the <a 2206href="http://www.w3.org/TR/xslt">XSLT</a> C library developed for the <a 2207href="http://www.gnome.org/">GNOME</a> project.</p> 2208 2209<p>Before starting reading this document it is highly recommended to get 2210familiar with <a href="internals.html">the libxslt internals</a>.</p> 2211 2212<p>Note: this documentation is by definition incomplete and I am not good at 2213spelling, grammar, so patches and suggestions are <a 2214href="mailto:veillard@redhat.com">really welcome</a>.</p> 2215 2216<h3><a name="Basics">Basics</a></h3> 2217 2218<p>The <a href="http://www.w3.org/TR/xslt">XSLT specification</a> provides 2219two <a href="http://www.w3.org/TR/xslt">ways to extend an XSLT engine</a>:</p> 2220<ul> 2221 <li>providing <a href="http://www.w3.org/TR/xslt">new extension 2222 functions</a> which can be called from XPath expressions</li> 2223 <li>providing <a href="http://www.w3.org/TR/xslt">new extension 2224 elements</a> which can be inserted in stylesheets</li> 2225</ul> 2226 2227<p>In both cases the extensions need to be associated to a new namespace, 2228i.e. an URI used as the name for the extension's namespace (there is no need 2229to have a resource there for this to work).</p> 2230 2231<p>libxslt provides a few extensions itself, either in the libxslt namespace 2232"http://xmlsoft.org/XSLT/namespace" or in namespaces for other well known 2233extensions provided by other XSLT processors like Saxon, Xalan or XT.</p> 2234 2235<h3><a name="Keep">Extension modules</a></h3> 2236 2237<p>Since extensions are bound to a namespace name, usually sets of extensions 2238coming from a given source are using the same namespace name defining in 2239practice a group of extensions providing elements, functions or both. From 2240the libxslt point of view those are considered as an "extension module", and 2241most of the APIs work at a module point of view.</p> 2242 2243<p>Registration of new functions or elements are bound to the activation of 2244the module. This is currently done by declaring the namespace as an extension 2245by using the attribute <code>extension-element-prefixes</code> on the 2246<code><a href="http://www.w3.org/TR/xslt">xsl:stylesheet</a></code> 2247element.</p> 2248 2249<p>An extension module is defined by 3 objects:</p> 2250<ul> 2251 <li>the namespace name associated</li> 2252 <li>an initialization function</li> 2253 <li>a shutdown function</li> 2254</ul> 2255 2256<h3><a name="Registerin">Registering a module</a></h3> 2257 2258<p>Currently a libxslt module has to be compiled within the application using 2259libxslt. There is no code to load dynamically shared libraries associated to 2260a namespace (this may be added but is likely to become a portability 2261nightmare).</p> 2262 2263<p>The current way to register a module is to link the code implementing it 2264with the application and to call a registration function:</p> 2265<pre>int xsltRegisterExtModule(const xmlChar *URI, 2266 xsltExtInitFunction initFunc, 2267 xsltExtShutdownFunction shutdownFunc);</pre> 2268 2269<p>The associated header is read by:</p> 2270<pre>#include<libxslt/extensions.h></pre> 2271 2272<p>which also defines the type for the initialization and shutdown 2273functions</p> 2274 2275<h3><a name="module">Loading a module</a></h3> 2276 2277<p>Once the module URI has been registered and if the XSLT processor detects 2278that a given stylesheet needs the functionalities of an extended module, this 2279one is initialized.</p> 2280 2281<p>The xsltExtInitFunction type defines the interface for an initialization 2282function:</p> 2283<pre>/** 2284 * xsltExtInitFunction: 2285 * @ctxt: an XSLT transformation context 2286 * @URI: the namespace URI for the extension 2287 * 2288 * A function called at initialization time of an XSLT 2289 * extension module 2290 * 2291 * Returns a pointer to the module specific data for this 2292 * transformation 2293 */ 2294typedef void *(*xsltExtInitFunction)(xsltTransformContextPtr ctxt, 2295 const xmlChar *URI);</pre> 2296 2297<p>There are 3 things to notice:</p> 2298<ul> 2299 <li>The function gets passed the namespace name URI as an argument. This 2300 allows a single function to provide the initialization for multiple 2301 logical modules.</li> 2302 <li>It also gets passed a transformation context. The initialization is 2303 done at run time before any processing occurs on the stylesheet but it 2304 will be invoked separately each time for each transformation.</li> 2305 <li>It returns a pointer. This can be used to store module specific 2306 information which can be retrieved later when a function or an element 2307 from the extension is used. An obvious example is a connection to a 2308 database which should be kept and reused along with the transformation. 2309 NULL is a perfectly valid return; there is no way to indicate a failure 2310 at this level</li> 2311</ul> 2312 2313<p>What this function is expected to do is:</p> 2314<ul> 2315 <li>prepare the context for this module (like opening the database 2316 connection)</li> 2317 <li>register the extensions specific to this module</li> 2318</ul> 2319 2320<h3><a name="Registerin1">Registering an extension function</a></h3> 2321 2322<p>There is a single call to do this registration:</p> 2323<pre>int xsltRegisterExtFunction(xsltTransformContextPtr ctxt, 2324 const xmlChar *name, 2325 const xmlChar *URI, 2326 xmlXPathEvalFunc function);</pre> 2327 2328<p>The registration is bound to a single transformation instance referred by 2329ctxt, name is the UTF8 encoded name for the NCName of the function, and URI 2330is the namespace name for the extension (no checking is done, a module could 2331register functions or elements from a different namespace, but it is not 2332recommended).</p> 2333 2334<h3><a name="Implementi">Implementing an extension function</a></h3> 2335 2336<p>The implementation of the function must have the signature of a libxml 2337XPath function:</p> 2338<pre>/** 2339 * xmlXPathEvalFunc: 2340 * @ctxt: an XPath parser context 2341 * @nargs: the number of arguments passed to the function 2342 * 2343 * an XPath evaluation function, the parameters are on the 2344 * XPath context stack 2345 */ 2346 2347typedef void (*xmlXPathEvalFunc)(xmlXPathParserContextPtr ctxt, 2348 int nargs);</pre> 2349 2350<p>The context passed to an XPath function is not an XSLT context but an <a 2351href="internals.html#XPath1">XPath context</a>. However it is possible to 2352find one from the other:</p> 2353<ul> 2354 <li>The function xsltXPathGetTransformContext provides this lookup facility: 2355 <pre>xsltTransformContextPtr 2356 xsltXPathGetTransformContext 2357 (xmlXPathParserContextPtr ctxt);</pre> 2358 </li> 2359 <li>The <code>xmlXPathContextPtr</code> associated to an 2360 <code>xsltTransformContext</code> is stored in the <code>xpathCtxt</code> 2361 field.</li> 2362</ul> 2363 2364<p>The first thing an extension function may want to do is to check the 2365arguments passed on the stack, the <code>nargs</code> parameter will tell how 2366many of them were provided on the XPath expression. The macro valuePop will 2367extract them from the XPath stack:</p> 2368<pre>#include <libxml/xpath.h> 2369#include <libxml/xpathInternals.h> 2370 2371xmlXPathObjectPtr obj = valuePop(ctxt); </pre> 2372 2373<p>Note that <code>ctxt</code> is the XPath context not the XSLT one. It is 2374then possible to examine the content of the value. Check <a 2375href="internals.html#Descriptio">the description of XPath objects</a> if 2376necessary. The following is a common sequence checking whether the argument 2377passed is a string and converting it using the built-in XPath 2378<code>string()</code> function if this is not the case:</p> 2379<pre>if (obj->type != XPATH_STRING) { 2380 valuePush(ctxt, obj); 2381 xmlXPathStringFunction(ctxt, 1); 2382 obj = valuePop(ctxt); 2383}</pre> 2384 2385<p>Most common XPath functions are available directly at the C level and are 2386exported either in <code><libxml/xpath.h></code> or in 2387<code><libxml/xpathInternals.h></code>.</p> 2388 2389<p>The extension function may also need to retrieve the data associated to 2390this module instance (the database connection in the previous example) this 2391can be done using the xsltGetExtData:</p> 2392<pre>void * xsltGetExtData(xsltTransformContextPtr ctxt, 2393 const xmlChar *URI);</pre> 2394 2395<p>Again the URI to be provided is the one which was used when registering 2396the module.</p> 2397 2398<p>Once the function finishes, don't forget to:</p> 2399<ul> 2400 <li>push the return value on the stack using <code>valuePush(ctxt, 2401 obj)</code></li> 2402 <li>deallocate the parameters passed to the function using 2403 <code>xmlXPathFreeObject(obj)</code></li> 2404</ul> 2405 2406<h3><a name="Examples">Examples for extension functions</a></h3> 2407 2408<p>The module libxslt/functions.c contains the sources of the XSLT built-in 2409functions, including document(), key(), generate-id(), etc. as well as a full 2410example module at the end. Here is the test function implementation for the 2411libxslt:test function:</p> 2412<pre>/** 2413 * xsltExtFunctionTest: 2414 * @ctxt: the XPath Parser context 2415 * @nargs: the number of arguments 2416 * 2417 * function libxslt:test() for testing the extensions support. 2418 */ 2419static void 2420xsltExtFunctionTest(xmlXPathParserContextPtr ctxt, int nargs) 2421{ 2422 xsltTransformContextPtr tctxt; 2423 void *data; 2424 2425 tctxt = xsltXPathGetTransformContext(ctxt); 2426 if (tctxt == NULL) { 2427 xsltGenericError(xsltGenericErrorContext, 2428 "xsltExtFunctionTest: failed to get the transformation context\n"); 2429 return; 2430 } 2431 data = xsltGetExtData(tctxt, (const xmlChar *) XSLT_DEFAULT_URL); 2432 if (data == NULL) { 2433 xsltGenericError(xsltGenericErrorContext, 2434 "xsltExtFunctionTest: failed to get module data\n"); 2435 return; 2436 } 2437#ifdef WITH_XSLT_DEBUG_FUNCTION 2438 xsltGenericDebug(xsltGenericDebugContext, 2439 "libxslt:test() called with %d args\n", nargs); 2440#endif 2441}</pre> 2442 2443<h3><a name="Registerin2">Registering an extension element</a></h3> 2444 2445<p>There is a single call to do this registration:</p> 2446<pre>int xsltRegisterExtElement(xsltTransformContextPtr ctxt, 2447 const xmlChar *name, 2448 const xmlChar *URI, 2449 xsltTransformFunction function);</pre> 2450 2451<p>It is similar to the mechanism used to register an extension function, 2452except that the signature of an extension element implementation is 2453different.</p> 2454 2455<p>The registration is bound to a single transformation instance referred to 2456by ctxt, name is the UTF8 encoded name for the NCName of the element, and URI 2457is the namespace name for the extension (no checking is done, a module could 2458register elements for a different namespace, but it is not recommended).</p> 2459 2460<h3><a name="Implementi1">Implementing an extension element</a></h3> 2461 2462<p>The implementation of the element must have the signature of an XSLT 2463transformation function:</p> 2464<pre>/** 2465 * xsltTransformFunction: 2466 * @ctxt: the XSLT transformation context 2467 * @node: the input node 2468 * @inst: the stylesheet node 2469 * @comp: the compiled information from the stylesheet 2470 * 2471 * signature of the function associated to elements part of the 2472 * stylesheet language like xsl:if or xsl:apply-templates. 2473 */ 2474typedef void (*xsltTransformFunction) 2475 (xsltTransformContextPtr ctxt, 2476 xmlNodePtr node, 2477 xmlNodePtr inst, 2478 xsltStylePreCompPtr comp);</pre> 2479 2480<p>The first argument is the XSLT transformation context. The second and 2481third arguments are xmlNodePtr i.e. internal memory <a 2482href="internals.html#libxml">representation of XML nodes</a>. They are 2483respectively <code>node</code> from the the input document being transformed 2484by the stylesheet and <code>inst</code> the extension element in the 2485stylesheet. The last argument is <code>comp</code> a pointer to a precompiled 2486representation of <code>inst</code> but usually for an extension function 2487this value is <code>NULL</code> by default (it could be added and associated 2488to the instruction in <code>inst->_private</code>).</p> 2489 2490<p>The same functions are available from a function implementing an extension 2491element as in an extension function, including 2492<code>xsltGetExtData()</code>.</p> 2493 2494<p>The goal of an extension element being usually to enrich the generated 2495output, it is expected that they will grow the currently generated output 2496tree. This can be done by grabbing ctxt->insert which is the current 2497libxml node being generated (Note this can also be the intermediate value 2498tree being built for example to initialize a variable, the processing should 2499be similar). The functions for libxml tree manipulation from <a 2500href="http://xmlsoft.org/html/libxml-tree.html"><libxml/tree.h></a> can 2501be employed to extend or modify the tree, but it is required to preserve the 2502insertion node and its ancestors since there are existing pointers to those 2503elements still in use in the XSLT template execution stack.</p> 2504 2505<h3><a name="Example">Example for extension elements</a></h3> 2506 2507<p>The module libxslt/transform.c contains the sources of the XSLT built-in 2508elements, including xsl:element, xsl:attribute, xsl:if, etc. There is a small 2509but full example in functions.c providing the implementation for the 2510libxslt:test element, it will output a comment in the result tree:</p> 2511<pre>/** 2512 * xsltExtElementTest: 2513 * @ctxt: an XSLT processing context 2514 * @node: The current node 2515 * @inst: the instruction in the stylesheet 2516 * @comp: precomputed information 2517 * 2518 * Process a libxslt:test node 2519 */ 2520static void 2521xsltExtElementTest(xsltTransformContextPtr ctxt, xmlNodePtr node, 2522 xmlNodePtr inst, 2523 xsltStylePreCompPtr comp) 2524{ 2525 xmlNodePtr comment; 2526 2527 if (ctxt == NULL) { 2528 xsltGenericError(xsltGenericErrorContext, 2529 "xsltExtElementTest: no transformation context\n"); 2530 return; 2531 } 2532 if (node == NULL) { 2533 xsltGenericError(xsltGenericErrorContext, 2534 "xsltExtElementTest: no current node\n"); 2535 return; 2536 } 2537 if (inst == NULL) { 2538 xsltGenericError(xsltGenericErrorContext, 2539 "xsltExtElementTest: no instruction\n"); 2540 return; 2541 } 2542 if (ctxt->insert == NULL) { 2543 xsltGenericError(xsltGenericErrorContext, 2544 "xsltExtElementTest: no insertion point\n"); 2545 return; 2546 } 2547 comment = 2548 xmlNewComment((const xmlChar *) 2549 "libxslt:test element test worked"); 2550 xmlAddChild(ctxt->insert, comment); 2551}</pre> 2552 2553<h3><a name="shutdown">The shutdown of a module</a></h3> 2554 2555<p>When the XSLT processor ends a transformation, the shutdown function (if 2556it exists) for each of the modules initialized is called. The 2557xsltExtShutdownFunction type defines the interface for a shutdown 2558function:</p> 2559<pre>/** 2560 * xsltExtShutdownFunction: 2561 * @ctxt: an XSLT transformation context 2562 * @URI: the namespace URI for the extension 2563 * @data: the data associated to this module 2564 * 2565 * A function called at shutdown time of an XSLT extension module 2566 */ 2567typedef void (*xsltExtShutdownFunction) (xsltTransformContextPtr ctxt, 2568 const xmlChar *URI, 2569 void *data);</pre> 2570 2571<p>This is really similar to a module initialization function except a third 2572argument is passed, it's the value that was returned by the initialization 2573function. This allows the routine to deallocate resources from the module for 2574example close the connection to the database to keep the same example.</p> 2575 2576<h3><a name="Future">Future work</a></h3> 2577 2578<p>Well, some of the pieces missing:</p> 2579<ul> 2580 <li>a way to load shared libraries to instantiate new modules</li> 2581 <li>a better detection of extension functions usage and their registration 2582 without having to use the extension prefix which ought to be reserved to 2583 element extensions.</li> 2584 <li>more examples</li> 2585 <li>implementations of the <a href="http://www.exslt.org/">EXSLT</a> common 2586 extension libraries, Thomas Broyer nearly finished implementing them.</li> 2587</ul> 2588 2589<p></p> 2590 2591<h2><a name="Contributi">Contributions</a></h2> 2592<ul> 2593 <li>Bjorn Reese is the author of the number support and worked on the 2594 XSLTMark support</li> 2595 <li>William Brack was an early adopted, contributed a number of patches and 2596 spent quite some time debugging non-trivial problems in early versions of 2597 libxslt</li> 2598 <li><a href="mailto:igor@zlatkovic.com">Igor Zlatkovic</a> is now the 2599 maintainer of the Windows port, <a 2600 href="http://www.zlatkovic.com/projects/libxml/index.html">he provides 2601 binaries</a></li> 2602 <li>Thomas Broyer provided a lot of suggestions, and drafted most of the 2603 extension API</li> 2604 <li>John Fleck maintains <a href="tutorial/libxslttutorial.html">a tutorial 2605 for libxslt</a></li> 2606 <li><a 2607 href="http://mail.gnome.org/archives/xml/2001-March/msg00014.html">Matt 2608 Sergeant</a> developed <a 2609 href="http://axkit.org/download/">XML::LibXSLT</a>, a perl wrapper for 2610 libxml2/libxslt as part of the <a href="http://axkit.com/">AxKit XML 2611 application server</a></li> 2612 <li>there is a module for <a 2613 href="http://acs-misc.sourceforge.net/nsxml.html">libxml/libxslt support 2614 in OpenNSD/AOLServer</a></li> 2615 <li><a href="mailto:dkuhlman@cutter.rexx.com">Dave Kuhlman</a> provides 2616 libxml/libxslt <a href="http://www.rexx.com/~dkuhlman">wrappers for 2617 Python</a></li> 2618 <li><a href="mailto:Steve.Ball@explain.com.au">Steve Ball</a>, and 2619 contributors maintain <a href="http://tclxml.sourceforge.net/">tcl 2620 bindings for libxml2 and libxslt</a>, as well as <a 2621 href="http://tclxml.sf.net/tkxmllint.html">tkxmllint</a> a GUI for 2622 xmllint and <a href="http://tclxml.sf.net/tkxsltproc.html">tkxsltproc</a> 2623 a GUI for xsltproc.</li> 2624 <li>If you want to use libxslt in a Mac OS X/Cocoa or Objective-C 2625 framework, Marc Liyanage provides <a 2626 href="http://www.entropy.ch/software/macosx/#testxslt">an application 2627 TestXSLT for XSLT and XML editing</a> including wrapper classes for the 2628 XML parser and XSLT processor.</li> 2629</ul> 2630 2631<p></p> 2632 2633<p><a href="mailto:daniel@veillard.com">Daniel Veillard</a></p> 2634</body> 2635</html> 2636
