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Diffstat (limited to 'bitbake/lib/bs4/builder/_lxml.py')
-rw-r--r-- | bitbake/lib/bs4/builder/_lxml.py | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/bitbake/lib/bs4/builder/_lxml.py b/bitbake/lib/bs4/builder/_lxml.py new file mode 100644 index 0000000000..fa5d49875e --- /dev/null +++ b/bitbake/lib/bs4/builder/_lxml.py | |||
@@ -0,0 +1,233 @@ | |||
1 | __all__ = [ | ||
2 | 'LXMLTreeBuilderForXML', | ||
3 | 'LXMLTreeBuilder', | ||
4 | ] | ||
5 | |||
6 | from io import BytesIO | ||
7 | from StringIO import StringIO | ||
8 | import collections | ||
9 | from lxml import etree | ||
10 | from bs4.element import Comment, Doctype, NamespacedAttribute | ||
11 | from bs4.builder import ( | ||
12 | FAST, | ||
13 | HTML, | ||
14 | HTMLTreeBuilder, | ||
15 | PERMISSIVE, | ||
16 | ParserRejectedMarkup, | ||
17 | TreeBuilder, | ||
18 | XML) | ||
19 | from bs4.dammit import EncodingDetector | ||
20 | |||
21 | LXML = 'lxml' | ||
22 | |||
23 | class LXMLTreeBuilderForXML(TreeBuilder): | ||
24 | DEFAULT_PARSER_CLASS = etree.XMLParser | ||
25 | |||
26 | is_xml = True | ||
27 | |||
28 | # Well, it's permissive by XML parser standards. | ||
29 | features = [LXML, XML, FAST, PERMISSIVE] | ||
30 | |||
31 | CHUNK_SIZE = 512 | ||
32 | |||
33 | # This namespace mapping is specified in the XML Namespace | ||
34 | # standard. | ||
35 | DEFAULT_NSMAPS = {'http://www.w3.org/XML/1998/namespace' : "xml"} | ||
36 | |||
37 | def default_parser(self, encoding): | ||
38 | # This can either return a parser object or a class, which | ||
39 | # will be instantiated with default arguments. | ||
40 | if self._default_parser is not None: | ||
41 | return self._default_parser | ||
42 | return etree.XMLParser( | ||
43 | target=self, strip_cdata=False, recover=True, encoding=encoding) | ||
44 | |||
45 | def parser_for(self, encoding): | ||
46 | # Use the default parser. | ||
47 | parser = self.default_parser(encoding) | ||
48 | |||
49 | if isinstance(parser, collections.Callable): | ||
50 | # Instantiate the parser with default arguments | ||
51 | parser = parser(target=self, strip_cdata=False, encoding=encoding) | ||
52 | return parser | ||
53 | |||
54 | def __init__(self, parser=None, empty_element_tags=None): | ||
55 | # TODO: Issue a warning if parser is present but not a | ||
56 | # callable, since that means there's no way to create new | ||
57 | # parsers for different encodings. | ||
58 | self._default_parser = parser | ||
59 | if empty_element_tags is not None: | ||
60 | self.empty_element_tags = set(empty_element_tags) | ||
61 | self.soup = None | ||
62 | self.nsmaps = [self.DEFAULT_NSMAPS] | ||
63 | |||
64 | def _getNsTag(self, tag): | ||
65 | # Split the namespace URL out of a fully-qualified lxml tag | ||
66 | # name. Copied from lxml's src/lxml/sax.py. | ||
67 | if tag[0] == '{': | ||
68 | return tuple(tag[1:].split('}', 1)) | ||
69 | else: | ||
70 | return (None, tag) | ||
71 | |||
72 | def prepare_markup(self, markup, user_specified_encoding=None, | ||
73 | document_declared_encoding=None): | ||
74 | """ | ||
75 | :yield: A series of 4-tuples. | ||
76 | (markup, encoding, declared encoding, | ||
77 | has undergone character replacement) | ||
78 | |||
79 | Each 4-tuple represents a strategy for parsing the document. | ||
80 | """ | ||
81 | if isinstance(markup, unicode): | ||
82 | # We were given Unicode. Maybe lxml can parse Unicode on | ||
83 | # this system? | ||
84 | yield markup, None, document_declared_encoding, False | ||
85 | |||
86 | if isinstance(markup, unicode): | ||
87 | # No, apparently not. Convert the Unicode to UTF-8 and | ||
88 | # tell lxml to parse it as UTF-8. | ||
89 | yield (markup.encode("utf8"), "utf8", | ||
90 | document_declared_encoding, False) | ||
91 | |||
92 | # Instead of using UnicodeDammit to convert the bytestring to | ||
93 | # Unicode using different encodings, use EncodingDetector to | ||
94 | # iterate over the encodings, and tell lxml to try to parse | ||
95 | # the document as each one in turn. | ||
96 | is_html = not self.is_xml | ||
97 | try_encodings = [user_specified_encoding, document_declared_encoding] | ||
98 | detector = EncodingDetector(markup, try_encodings, is_html) | ||
99 | for encoding in detector.encodings: | ||
100 | yield (detector.markup, encoding, document_declared_encoding, False) | ||
101 | |||
102 | def feed(self, markup): | ||
103 | if isinstance(markup, bytes): | ||
104 | markup = BytesIO(markup) | ||
105 | elif isinstance(markup, unicode): | ||
106 | markup = StringIO(markup) | ||
107 | |||
108 | # Call feed() at least once, even if the markup is empty, | ||
109 | # or the parser won't be initialized. | ||
110 | data = markup.read(self.CHUNK_SIZE) | ||
111 | try: | ||
112 | self.parser = self.parser_for(self.soup.original_encoding) | ||
113 | self.parser.feed(data) | ||
114 | while len(data) != 0: | ||
115 | # Now call feed() on the rest of the data, chunk by chunk. | ||
116 | data = markup.read(self.CHUNK_SIZE) | ||
117 | if len(data) != 0: | ||
118 | self.parser.feed(data) | ||
119 | self.parser.close() | ||
120 | except (UnicodeDecodeError, LookupError, etree.ParserError), e: | ||
121 | raise ParserRejectedMarkup(str(e)) | ||
122 | |||
123 | def close(self): | ||
124 | self.nsmaps = [self.DEFAULT_NSMAPS] | ||
125 | |||
126 | def start(self, name, attrs, nsmap={}): | ||
127 | # Make sure attrs is a mutable dict--lxml may send an immutable dictproxy. | ||
128 | attrs = dict(attrs) | ||
129 | nsprefix = None | ||
130 | # Invert each namespace map as it comes in. | ||
131 | if len(self.nsmaps) > 1: | ||
132 | # There are no new namespaces for this tag, but | ||
133 | # non-default namespaces are in play, so we need a | ||
134 | # separate tag stack to know when they end. | ||
135 | self.nsmaps.append(None) | ||
136 | elif len(nsmap) > 0: | ||
137 | # A new namespace mapping has come into play. | ||
138 | inverted_nsmap = dict((value, key) for key, value in nsmap.items()) | ||
139 | self.nsmaps.append(inverted_nsmap) | ||
140 | # Also treat the namespace mapping as a set of attributes on the | ||
141 | # tag, so we can recreate it later. | ||
142 | attrs = attrs.copy() | ||
143 | for prefix, namespace in nsmap.items(): | ||
144 | attribute = NamespacedAttribute( | ||
145 | "xmlns", prefix, "http://www.w3.org/2000/xmlns/") | ||
146 | attrs[attribute] = namespace | ||
147 | |||
148 | # Namespaces are in play. Find any attributes that came in | ||
149 | # from lxml with namespaces attached to their names, and | ||
150 | # turn then into NamespacedAttribute objects. | ||
151 | new_attrs = {} | ||
152 | for attr, value in attrs.items(): | ||
153 | namespace, attr = self._getNsTag(attr) | ||
154 | if namespace is None: | ||
155 | new_attrs[attr] = value | ||
156 | else: | ||
157 | nsprefix = self._prefix_for_namespace(namespace) | ||
158 | attr = NamespacedAttribute(nsprefix, attr, namespace) | ||
159 | new_attrs[attr] = value | ||
160 | attrs = new_attrs | ||
161 | |||
162 | namespace, name = self._getNsTag(name) | ||
163 | nsprefix = self._prefix_for_namespace(namespace) | ||
164 | self.soup.handle_starttag(name, namespace, nsprefix, attrs) | ||
165 | |||
166 | def _prefix_for_namespace(self, namespace): | ||
167 | """Find the currently active prefix for the given namespace.""" | ||
168 | if namespace is None: | ||
169 | return None | ||
170 | for inverted_nsmap in reversed(self.nsmaps): | ||
171 | if inverted_nsmap is not None and namespace in inverted_nsmap: | ||
172 | return inverted_nsmap[namespace] | ||
173 | return None | ||
174 | |||
175 | def end(self, name): | ||
176 | self.soup.endData() | ||
177 | completed_tag = self.soup.tagStack[-1] | ||
178 | namespace, name = self._getNsTag(name) | ||
179 | nsprefix = None | ||
180 | if namespace is not None: | ||
181 | for inverted_nsmap in reversed(self.nsmaps): | ||
182 | if inverted_nsmap is not None and namespace in inverted_nsmap: | ||
183 | nsprefix = inverted_nsmap[namespace] | ||
184 | break | ||
185 | self.soup.handle_endtag(name, nsprefix) | ||
186 | if len(self.nsmaps) > 1: | ||
187 | # This tag, or one of its parents, introduced a namespace | ||
188 | # mapping, so pop it off the stack. | ||
189 | self.nsmaps.pop() | ||
190 | |||
191 | def pi(self, target, data): | ||
192 | pass | ||
193 | |||
194 | def data(self, content): | ||
195 | self.soup.handle_data(content) | ||
196 | |||
197 | def doctype(self, name, pubid, system): | ||
198 | self.soup.endData() | ||
199 | doctype = Doctype.for_name_and_ids(name, pubid, system) | ||
200 | self.soup.object_was_parsed(doctype) | ||
201 | |||
202 | def comment(self, content): | ||
203 | "Handle comments as Comment objects." | ||
204 | self.soup.endData() | ||
205 | self.soup.handle_data(content) | ||
206 | self.soup.endData(Comment) | ||
207 | |||
208 | def test_fragment_to_document(self, fragment): | ||
209 | """See `TreeBuilder`.""" | ||
210 | return u'<?xml version="1.0" encoding="utf-8"?>\n%s' % fragment | ||
211 | |||
212 | |||
213 | class LXMLTreeBuilder(HTMLTreeBuilder, LXMLTreeBuilderForXML): | ||
214 | |||
215 | features = [LXML, HTML, FAST, PERMISSIVE] | ||
216 | is_xml = False | ||
217 | |||
218 | def default_parser(self, encoding): | ||
219 | return etree.HTMLParser | ||
220 | |||
221 | def feed(self, markup): | ||
222 | encoding = self.soup.original_encoding | ||
223 | try: | ||
224 | self.parser = self.parser_for(encoding) | ||
225 | self.parser.feed(markup) | ||
226 | self.parser.close() | ||
227 | except (UnicodeDecodeError, LookupError, etree.ParserError), e: | ||
228 | raise ParserRejectedMarkup(str(e)) | ||
229 | |||
230 | |||
231 | def test_fragment_to_document(self, fragment): | ||
232 | """See `TreeBuilder`.""" | ||
233 | return u'<html><body>%s</body></html>' % fragment | ||