__all__ = [ 'HTML5TreeBuilder', ] from pdb import set_trace import warnings from bs4.builder import ( PERMISSIVE, HTML, HTML_5, HTMLTreeBuilder, ) from bs4.element import ( NamespacedAttribute, whitespace_re, ) import html5lib from html5lib.constants import namespaces from bs4.element import ( Comment, Doctype, NavigableString, Tag, ) class HTML5TreeBuilder(HTMLTreeBuilder): """Use html5lib to build a tree.""" NAME = "html5lib" features = [NAME, PERMISSIVE, HTML_5, HTML] def prepare_markup(self, markup, user_specified_encoding, document_declared_encoding=None, exclude_encodings=None): # Store the user-specified encoding for use later on. self.user_specified_encoding = user_specified_encoding # document_declared_encoding and exclude_encodings aren't used # ATM because the html5lib TreeBuilder doesn't use # UnicodeDammit. if exclude_encodings: warnings.warn("You provided a value for exclude_encoding, but the html5lib tree builder doesn't support exclude_encoding.") yield (markup, None, None, False) # These methods are defined by Beautiful Soup. def feed(self, markup): if self.soup.parse_only is not None: warnings.warn("You provided a value for parse_only, but the html5lib tree builder doesn't support parse_only. The entire document will be parsed.") parser = html5lib.HTMLParser(tree=self.create_treebuilder) doc = parser.parse(markup, encoding=self.user_specified_encoding) # Set the character encoding detected by the tokenizer. if isinstance(markup, str): # We need to special-case this because html5lib sets # charEncoding to UTF-8 if it gets Unicode input. doc.original_encoding = None else: doc.original_encoding = parser.tokenizer.stream.charEncoding[0] def create_treebuilder(self, namespaceHTMLElements): self.underlying_builder = TreeBuilderForHtml5lib( self.soup, namespaceHTMLElements) return self.underlying_builder def test_fragment_to_document(self, fragment): """See `TreeBuilder`.""" return '%s' % fragment class TreeBuilderForHtml5lib(html5lib.treebuilders._base.TreeBuilder): def __init__(self, soup, namespaceHTMLElements): self.soup = soup super(TreeBuilderForHtml5lib, self).__init__(namespaceHTMLElements) def documentClass(self): self.soup.reset() return Element(self.soup, self.soup, None) def insertDoctype(self, token): name = token["name"] publicId = token["publicId"] systemId = token["systemId"] doctype = Doctype.for_name_and_ids(name, publicId, systemId) self.soup.object_was_parsed(doctype) def elementClass(self, name, namespace): tag = self.soup.new_tag(name, namespace) return Element(tag, self.soup, namespace) def commentClass(self, data): return TextNode(Comment(data), self.soup) def fragmentClass(self): self.soup = BeautifulSoup("") self.soup.name = "[document_fragment]" return Element(self.soup, self.soup, None) def appendChild(self, node): # XXX This code is not covered by the BS4 tests. self.soup.append(node.element) def getDocument(self): return self.soup def getFragment(self): return html5lib.treebuilders._base.TreeBuilder.getFragment(self).element class AttrList(object): def __init__(self, element): self.element = element self.attrs = dict(self.element.attrs) def __iter__(self): return list(self.attrs.items()).__iter__() def __setitem__(self, name, value): # If this attribute is a multi-valued attribute for this element, # turn its value into a list. list_attr = HTML5TreeBuilder.cdata_list_attributes if (name in list_attr['*'] or (self.element.name in list_attr and name in list_attr[self.element.name])): # A node that is being cloned may have already undergone # this procedure. if not isinstance(value, list): value = whitespace_re.split(value) self.element[name] = value def items(self): return list(self.attrs.items()) def keys(self): return list(self.attrs.keys()) def __len__(self): return len(self.attrs) def __getitem__(self, name): return self.attrs[name] def __contains__(self, name): return name in list(self.attrs.keys()) class Element(html5lib.treebuilders._base.Node): def __init__(self, element, soup, namespace): html5lib.treebuilders._base.Node.__init__(self, element.name) self.element = element self.soup = soup self.namespace = namespace def appendChild(self, node): string_child = child = None if isinstance(node, str): # Some other piece of code decided to pass in a string # instead of creating a TextElement object to contain the # string. string_child = child = node elif isinstance(node, Tag): # Some other piece of code decided to pass in a Tag # instead of creating an Element object to contain the # Tag. child = node elif node.element.__class__ == NavigableString: string_child = child = node.element else: child = node.element if not isinstance(child, str) and child.parent is not None: node.element.extract() if (string_child and self.element.contents and self.element.contents[-1].__class__ == NavigableString): # We are appending a string onto another string. # TODO This has O(n^2) performance, for input like # "aaa..." old_element = self.element.contents[-1] new_element = self.soup.new_string(old_element + string_child) old_element.replace_with(new_element) self.soup._most_recent_element = new_element else: if isinstance(node, str): # Create a brand new NavigableString from this string. child = self.soup.new_string(node) # Tell Beautiful Soup to act as if it parsed this element # immediately after the parent's last descendant. (Or # immediately after the parent, if it has no children.) if self.element.contents: most_recent_element = self.element._last_descendant(False) elif self.element.next_element is not None: # Something from further ahead in the parse tree is # being inserted into this earlier element. This is # very annoying because it means an expensive search # for the last element in the tree. most_recent_element = self.soup._last_descendant() else: most_recent_element = self.element self.soup.object_was_parsed( child, parent=self.element, most_recent_element=most_recent_element) def getAttributes(self): return AttrList(self.element) def setAttributes(self, attributes): if attributes is not None and len(attributes) > 0: converted_attributes = [] for name, value in list(attributes.items()): if isinstance(name, tuple): new_name = NamespacedAttribute(*name) del attributes[name] attributes[new_name] = value self.soup.builder._replace_cdata_list_attribute_values( self.name, attributes) for name, value in list(attributes.items()): self.element[name] = value # The attributes may contain variables that need substitution. # Call set_up_substitutions manually. # # The Tag constructor called this method when the Tag was created, # but we just set/changed the attributes, so call it again. self.soup.builder.set_up_substitutions(self.element) attributes = property(getAttributes, setAttributes) def insertText(self, data, insertBefore=None): if insertBefore: text = TextNode(self.soup.new_string(data), self.soup) self.insertBefore(data, insertBefore) else: self.appendChild(data) def insertBefore(self, node, refNode): index = self.element.index(refNode.element) if (node.element.__class__ == NavigableString and self.element.contents and self.element.contents[index-1].__class__ == NavigableString): # (See comments in appendChild) old_node = self.element.contents[index-1] new_str = self.soup.new_string(old_node + node.element) old_node.replace_with(new_str) else: self.element.insert(index, node.element) node.parent = self def removeChild(self, node): node.element.extract() def reparentChildren(self, new_parent): """Move all of this tag's children into another tag.""" # print "MOVE", self.element.contents # print "FROM", self.element # print "TO", new_parent.element element = self.element new_parent_element = new_parent.element # Determine what this tag's next_element will be once all the children # are removed. final_next_element = element.next_sibling new_parents_last_descendant = new_parent_element._last_descendant(False, False) if len(new_parent_element.contents) > 0: # The new parent already contains children. We will be # appending this tag's children to the end. new_parents_last_child = new_parent_element.contents[-1] new_parents_last_descendant_next_element = new_parents_last_descendant.next_element else: # The new parent contains no children. new_parents_last_child = None new_parents_last_descendant_next_element = new_parent_element.next_element to_append = element.contents append_after = new_parent_element.contents if len(to_append) > 0: # Set the first child's previous_element and previous_sibling # to elements within the new parent first_child = to_append[0] if new_parents_last_descendant: first_child.previous_element = new_parents_last_descendant else: first_child.previous_element = new_parent_element first_child.previous_sibling = new_parents_last_child if new_parents_last_descendant: new_parents_last_descendant.next_element = first_child else: new_parent_element.next_element = first_child if new_parents_last_child: new_parents_last_child.next_sibling = first_child # Fix the last child's next_element and next_sibling last_child = to_append[-1] last_child.next_element = new_parents_last_descendant_next_element if new_parents_last_descendant_next_element: new_parents_last_descendant_next_element.previous_element = last_child last_child.next_sibling = None for child in to_append: child.parent = new_parent_element new_parent_element.contents.append(child) # Now that this element has no children, change its .next_element. element.contents = [] element.next_element = final_next_element # print "DONE WITH MOVE" # print "FROM", self.element # print "TO", new_parent_element def cloneNode(self): tag = self.soup.new_tag(self.element.name, self.namespace) node = Element(tag, self.soup, self.namespace) for key,value in self.attributes: node.attributes[key] = value return node def hasContent(self): return self.element.contents def getNameTuple(self): if self.namespace == None: return namespaces["html"], self.name else: return self.namespace, self.name nameTuple = property(getNameTuple) class TextNode(Element): def __init__(self, element, soup): html5lib.treebuilders._base.Node.__init__(self, None) self.element = element self.soup = soup def cloneNode(self): raise NotImplementedError