1require 'xmlscan/scanner'
2require 'stringio'
3
4module RSS
5
6  class XMLScanParser < BaseParser
7
8    class << self
9      def listener
10        XMLScanListener
11      end
12    end
13
14    private
15    def _parse
16      begin
17        if @rss.is_a?(String)
18          input = StringIO.new(@rss)
19        else
20          input = @rss
21        end
22        scanner = XMLScan::XMLScanner.new(@listener)
23        scanner.parse(input)
24      rescue XMLScan::Error => e
25        lineno = e.lineno || scanner.lineno || input.lineno
26        raise NotWellFormedError.new(lineno){e.message}
27      end
28    end
29
30  end
31
32  class XMLScanListener < BaseListener
33
34    include XMLScan::Visitor
35    include ListenerMixin
36
37    ENTITIES = {
38      'lt' => '<',
39      'gt' => '>',
40      'amp' => '&',
41      'quot' => '"',
42      'apos' => '\''
43    }
44
45    def on_xmldecl_version(str)
46      @version = str
47    end
48
49    def on_xmldecl_encoding(str)
50      @encoding = str
51    end
52
53    def on_xmldecl_standalone(str)
54      @standalone = str
55    end
56
57    def on_xmldecl_end
58      xmldecl(@version, @encoding, @standalone == "yes")
59    end
60
61    alias_method(:on_pi, :instruction)
62    alias_method(:on_chardata, :text)
63    alias_method(:on_cdata, :text)
64
65    def on_etag(name)
66      tag_end(name)
67    end
68
69    def on_entityref(ref)
70      text(entity(ref))
71    end
72
73    def on_charref(code)
74      text([code].pack('U'))
75    end
76
77    alias_method(:on_charref_hex, :on_charref)
78
79    def on_stag(name)
80      @attrs = {}
81    end
82
83    def on_attribute(name)
84      @attrs[name] = @current_attr = ''
85    end
86
87    def on_attr_value(str)
88      @current_attr << str
89    end
90
91    def on_attr_entityref(ref)
92      @current_attr << entity(ref)
93    end
94
95    def on_attr_charref(code)
96      @current_attr << [code].pack('U')
97    end
98
99    alias_method(:on_attr_charref_hex, :on_attr_charref)
100
101    def on_stag_end(name)
102      tag_start(name, @attrs)
103    end
104
105    def on_stag_end_empty(name)
106      tag_start(name, @attrs)
107      tag_end(name)
108    end
109
110    private
111    def entity(ref)
112      ent = ENTITIES[ref]
113      if ent
114        ent
115      else
116        wellformed_error("undefined entity: #{ref}")
117      end
118    end
119  end
120
121end
122