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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 | ||
