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Diffstat (limited to 'import-layers/yocto-poky/bitbake/lib/bs4/builder/_lxml.py')
-rw-r--r-- | import-layers/yocto-poky/bitbake/lib/bs4/builder/_lxml.py | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/import-layers/yocto-poky/bitbake/lib/bs4/builder/_lxml.py b/import-layers/yocto-poky/bitbake/lib/bs4/builder/_lxml.py new file mode 100644 index 000000000..fa5d49875 --- /dev/null +++ b/import-layers/yocto-poky/bitbake/lib/bs4/builder/_lxml.py @@ -0,0 +1,233 @@ +__all__ = [ + 'LXMLTreeBuilderForXML', + 'LXMLTreeBuilder', + ] + +from io import BytesIO +from StringIO import StringIO +import collections +from lxml import etree +from bs4.element import Comment, Doctype, NamespacedAttribute +from bs4.builder import ( + FAST, + HTML, + HTMLTreeBuilder, + PERMISSIVE, + ParserRejectedMarkup, + TreeBuilder, + XML) +from bs4.dammit import EncodingDetector + +LXML = 'lxml' + +class LXMLTreeBuilderForXML(TreeBuilder): + DEFAULT_PARSER_CLASS = etree.XMLParser + + is_xml = True + + # Well, it's permissive by XML parser standards. + features = [LXML, XML, FAST, PERMISSIVE] + + CHUNK_SIZE = 512 + + # This namespace mapping is specified in the XML Namespace + # standard. + DEFAULT_NSMAPS = {'http://www.w3.org/XML/1998/namespace' : "xml"} + + def default_parser(self, encoding): + # This can either return a parser object or a class, which + # will be instantiated with default arguments. + if self._default_parser is not None: + return self._default_parser + return etree.XMLParser( + target=self, strip_cdata=False, recover=True, encoding=encoding) + + def parser_for(self, encoding): + # Use the default parser. + parser = self.default_parser(encoding) + + if isinstance(parser, collections.Callable): + # Instantiate the parser with default arguments + parser = parser(target=self, strip_cdata=False, encoding=encoding) + return parser + + def __init__(self, parser=None, empty_element_tags=None): + # TODO: Issue a warning if parser is present but not a + # callable, since that means there's no way to create new + # parsers for different encodings. + self._default_parser = parser + if empty_element_tags is not None: + self.empty_element_tags = set(empty_element_tags) + self.soup = None + self.nsmaps = [self.DEFAULT_NSMAPS] + + def _getNsTag(self, tag): + # Split the namespace URL out of a fully-qualified lxml tag + # name. Copied from lxml's src/lxml/sax.py. + if tag[0] == '{': + return tuple(tag[1:].split('}', 1)) + else: + return (None, tag) + + def prepare_markup(self, markup, user_specified_encoding=None, + document_declared_encoding=None): + """ + :yield: A series of 4-tuples. + (markup, encoding, declared encoding, + has undergone character replacement) + + Each 4-tuple represents a strategy for parsing the document. + """ + if isinstance(markup, unicode): + # We were given Unicode. Maybe lxml can parse Unicode on + # this system? + yield markup, None, document_declared_encoding, False + + if isinstance(markup, unicode): + # No, apparently not. Convert the Unicode to UTF-8 and + # tell lxml to parse it as UTF-8. + yield (markup.encode("utf8"), "utf8", + document_declared_encoding, False) + + # Instead of using UnicodeDammit to convert the bytestring to + # Unicode using different encodings, use EncodingDetector to + # iterate over the encodings, and tell lxml to try to parse + # the document as each one in turn. + is_html = not self.is_xml + try_encodings = [user_specified_encoding, document_declared_encoding] + detector = EncodingDetector(markup, try_encodings, is_html) + for encoding in detector.encodings: + yield (detector.markup, encoding, document_declared_encoding, False) + + def feed(self, markup): + if isinstance(markup, bytes): + markup = BytesIO(markup) + elif isinstance(markup, unicode): + markup = StringIO(markup) + + # Call feed() at least once, even if the markup is empty, + # or the parser won't be initialized. + data = markup.read(self.CHUNK_SIZE) + try: + self.parser = self.parser_for(self.soup.original_encoding) + self.parser.feed(data) + while len(data) != 0: + # Now call feed() on the rest of the data, chunk by chunk. + data = markup.read(self.CHUNK_SIZE) + if len(data) != 0: + self.parser.feed(data) + self.parser.close() + except (UnicodeDecodeError, LookupError, etree.ParserError), e: + raise ParserRejectedMarkup(str(e)) + + def close(self): + self.nsmaps = [self.DEFAULT_NSMAPS] + + def start(self, name, attrs, nsmap={}): + # Make sure attrs is a mutable dict--lxml may send an immutable dictproxy. + attrs = dict(attrs) + nsprefix = None + # Invert each namespace map as it comes in. + if len(self.nsmaps) > 1: + # There are no new namespaces for this tag, but + # non-default namespaces are in play, so we need a + # separate tag stack to know when they end. + self.nsmaps.append(None) + elif len(nsmap) > 0: + # A new namespace mapping has come into play. + inverted_nsmap = dict((value, key) for key, value in nsmap.items()) + self.nsmaps.append(inverted_nsmap) + # Also treat the namespace mapping as a set of attributes on the + # tag, so we can recreate it later. + attrs = attrs.copy() + for prefix, namespace in nsmap.items(): + attribute = NamespacedAttribute( + "xmlns", prefix, "http://www.w3.org/2000/xmlns/") + attrs[attribute] = namespace + + # Namespaces are in play. Find any attributes that came in + # from lxml with namespaces attached to their names, and + # turn then into NamespacedAttribute objects. + new_attrs = {} + for attr, value in attrs.items(): + namespace, attr = self._getNsTag(attr) + if namespace is None: + new_attrs[attr] = value + else: + nsprefix = self._prefix_for_namespace(namespace) + attr = NamespacedAttribute(nsprefix, attr, namespace) + new_attrs[attr] = value + attrs = new_attrs + + namespace, name = self._getNsTag(name) + nsprefix = self._prefix_for_namespace(namespace) + self.soup.handle_starttag(name, namespace, nsprefix, attrs) + + def _prefix_for_namespace(self, namespace): + """Find the currently active prefix for the given namespace.""" + if namespace is None: + return None + for inverted_nsmap in reversed(self.nsmaps): + if inverted_nsmap is not None and namespace in inverted_nsmap: + return inverted_nsmap[namespace] + return None + + def end(self, name): + self.soup.endData() + completed_tag = self.soup.tagStack[-1] + namespace, name = self._getNsTag(name) + nsprefix = None + if namespace is not None: + for inverted_nsmap in reversed(self.nsmaps): + if inverted_nsmap is not None and namespace in inverted_nsmap: + nsprefix = inverted_nsmap[namespace] + break + self.soup.handle_endtag(name, nsprefix) + if len(self.nsmaps) > 1: + # This tag, or one of its parents, introduced a namespace + # mapping, so pop it off the stack. + self.nsmaps.pop() + + def pi(self, target, data): + pass + + def data(self, content): + self.soup.handle_data(content) + + def doctype(self, name, pubid, system): + self.soup.endData() + doctype = Doctype.for_name_and_ids(name, pubid, system) + self.soup.object_was_parsed(doctype) + + def comment(self, content): + "Handle comments as Comment objects." + self.soup.endData() + self.soup.handle_data(content) + self.soup.endData(Comment) + + def test_fragment_to_document(self, fragment): + """See `TreeBuilder`.""" + return u'<?xml version="1.0" encoding="utf-8"?>\n%s' % fragment + + +class LXMLTreeBuilder(HTMLTreeBuilder, LXMLTreeBuilderForXML): + + features = [LXML, HTML, FAST, PERMISSIVE] + is_xml = False + + def default_parser(self, encoding): + return etree.HTMLParser + + def feed(self, markup): + encoding = self.soup.original_encoding + try: + self.parser = self.parser_for(encoding) + self.parser.feed(markup) + self.parser.close() + except (UnicodeDecodeError, LookupError, etree.ParserError), e: + raise ParserRejectedMarkup(str(e)) + + + def test_fragment_to_document(self, fragment): + """See `TreeBuilder`.""" + return u'<html><body>%s</body></html>' % fragment |