595 lines
22 KiB
Python
595 lines
22 KiB
Python
# Use of this source code is governed by the MIT license.
|
|
__license__ = "MIT"
|
|
|
|
__all__ = [
|
|
"HTML5TreeBuilder",
|
|
]
|
|
|
|
from typing import (
|
|
Any,
|
|
cast,
|
|
Dict,
|
|
Iterable,
|
|
Optional,
|
|
Sequence,
|
|
TYPE_CHECKING,
|
|
Tuple,
|
|
Union,
|
|
)
|
|
from typing_extensions import TypeAlias
|
|
from bs4._typing import (
|
|
_AttributeValue,
|
|
_AttributeValues,
|
|
_Encoding,
|
|
_Encodings,
|
|
_NamespaceURL,
|
|
_RawMarkup,
|
|
)
|
|
|
|
import warnings
|
|
from bs4.builder import (
|
|
DetectsXMLParsedAsHTML,
|
|
PERMISSIVE,
|
|
HTML,
|
|
HTML_5,
|
|
HTMLTreeBuilder,
|
|
)
|
|
from bs4.element import (
|
|
NamespacedAttribute,
|
|
PageElement,
|
|
nonwhitespace_re,
|
|
)
|
|
import html5lib
|
|
from html5lib.constants import (
|
|
namespaces,
|
|
)
|
|
from bs4.element import (
|
|
Comment,
|
|
Doctype,
|
|
NavigableString,
|
|
Tag,
|
|
)
|
|
|
|
if TYPE_CHECKING:
|
|
from bs4 import BeautifulSoup
|
|
|
|
from html5lib.treebuilders import base as treebuilder_base
|
|
|
|
|
|
class HTML5TreeBuilder(HTMLTreeBuilder):
|
|
"""Use `html5lib <https://github.com/html5lib/html5lib-python>`_ to
|
|
build a tree.
|
|
|
|
Note that `HTML5TreeBuilder` does not support some common HTML
|
|
`TreeBuilder` features. Some of these features could theoretically
|
|
be implemented, but at the very least it's quite difficult,
|
|
because html5lib moves the parse tree around as it's being built.
|
|
|
|
Specifically:
|
|
|
|
* This `TreeBuilder` doesn't use different subclasses of
|
|
`NavigableString` (e.g. `Script`) based on the name of the tag
|
|
in which the string was found.
|
|
* You can't use a `SoupStrainer` to parse only part of a document.
|
|
"""
|
|
|
|
NAME: str = "html5lib"
|
|
|
|
features: Sequence[str] = [NAME, PERMISSIVE, HTML_5, HTML]
|
|
|
|
#: html5lib can tell us which line number and position in the
|
|
#: original file is the source of an element.
|
|
TRACKS_LINE_NUMBERS: bool = True
|
|
|
|
underlying_builder: "TreeBuilderForHtml5lib" #: :meta private:
|
|
user_specified_encoding: Optional[_Encoding]
|
|
|
|
def prepare_markup(
|
|
self,
|
|
markup: _RawMarkup,
|
|
user_specified_encoding: Optional[_Encoding] = None,
|
|
document_declared_encoding: Optional[_Encoding] = None,
|
|
exclude_encodings: Optional[_Encodings] = None,
|
|
) -> Iterable[Tuple[_RawMarkup, Optional[_Encoding], Optional[_Encoding], bool]]:
|
|
# 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.
|
|
for variable, name in (
|
|
(document_declared_encoding, "document_declared_encoding"),
|
|
(exclude_encodings, "exclude_encodings"),
|
|
):
|
|
if variable:
|
|
warnings.warn(
|
|
f"You provided a value for {name}, but the html5lib tree builder doesn't support {name}.",
|
|
stacklevel=3,
|
|
)
|
|
|
|
# html5lib only parses HTML, so if it's given XML that's worth
|
|
# noting.
|
|
DetectsXMLParsedAsHTML.warn_if_markup_looks_like_xml(markup, stacklevel=3)
|
|
|
|
yield (markup, None, None, False)
|
|
|
|
# These methods are defined by Beautiful Soup.
|
|
def feed(self, markup: _RawMarkup) -> None:
|
|
"""Run some incoming markup through some parsing process,
|
|
populating the `BeautifulSoup` object in `HTML5TreeBuilder.soup`.
|
|
"""
|
|
if self.soup is not None and 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.",
|
|
stacklevel=4,
|
|
)
|
|
|
|
# self.underlying_builder is probably None now, but it'll be set
|
|
# when html5lib calls self.create_treebuilder().
|
|
parser = html5lib.HTMLParser(tree=self.create_treebuilder)
|
|
assert self.underlying_builder is not None
|
|
self.underlying_builder.parser = parser
|
|
extra_kwargs = dict()
|
|
if not isinstance(markup, str):
|
|
# kwargs, specifically override_encoding, will eventually
|
|
# be passed in to html5lib's
|
|
# HTMLBinaryInputStream.__init__.
|
|
extra_kwargs["override_encoding"] = self.user_specified_encoding
|
|
|
|
doc = parser.parse(markup, **extra_kwargs)
|
|
|
|
# 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:
|
|
original_encoding = parser.tokenizer.stream.charEncoding[0]
|
|
# The encoding is an html5lib Encoding object. We want to
|
|
# use a string for compatibility with other tree builders.
|
|
original_encoding = original_encoding.name
|
|
doc.original_encoding = original_encoding
|
|
self.underlying_builder.parser = None
|
|
|
|
def create_treebuilder(
|
|
self, namespaceHTMLElements: bool
|
|
) -> "TreeBuilderForHtml5lib":
|
|
"""Called by html5lib to instantiate the kind of class it
|
|
calls a 'TreeBuilder'.
|
|
|
|
:param namespaceHTMLElements: Whether or not to namespace HTML elements.
|
|
|
|
:meta private:
|
|
"""
|
|
self.underlying_builder = TreeBuilderForHtml5lib(
|
|
namespaceHTMLElements, self.soup, store_line_numbers=self.store_line_numbers
|
|
)
|
|
return self.underlying_builder
|
|
|
|
def test_fragment_to_document(self, fragment: str) -> str:
|
|
"""See `TreeBuilder`."""
|
|
return "<html><head></head><body>%s</body></html>" % fragment
|
|
|
|
|
|
class TreeBuilderForHtml5lib(treebuilder_base.TreeBuilder):
|
|
soup: "BeautifulSoup" #: :meta private:
|
|
parser: Optional[html5lib.HTMLParser] #: :meta private:
|
|
|
|
def __init__(
|
|
self,
|
|
namespaceHTMLElements: bool,
|
|
soup: Optional["BeautifulSoup"] = None,
|
|
store_line_numbers: bool = True,
|
|
**kwargs: Any,
|
|
):
|
|
if soup:
|
|
self.soup = soup
|
|
else:
|
|
warnings.warn(
|
|
"The optionality of the 'soup' argument to the TreeBuilderForHtml5lib constructor is deprecated as of Beautiful Soup 4.13.0: 'soup' is now required. If you can't pass in a BeautifulSoup object here, or you get this warning and it seems mysterious to you, please contact the Beautiful Soup developer team for possible un-deprecation.",
|
|
DeprecationWarning,
|
|
stacklevel=2,
|
|
)
|
|
from bs4 import BeautifulSoup
|
|
|
|
# TODO: Why is the parser 'html.parser' here? Using
|
|
# html5lib doesn't cause an infinite loop and is more
|
|
# accurate. Best to get rid of this entire section, I think.
|
|
self.soup = BeautifulSoup(
|
|
"", "html.parser", store_line_numbers=store_line_numbers, **kwargs
|
|
)
|
|
# TODO: What are **kwargs exactly? Should they be passed in
|
|
# here in addition to/instead of being passed to the BeautifulSoup
|
|
# constructor?
|
|
super(TreeBuilderForHtml5lib, self).__init__(namespaceHTMLElements)
|
|
|
|
# This will be set later to a real html5lib HTMLParser object,
|
|
# which we can use to track the current line number.
|
|
self.parser = None
|
|
self.store_line_numbers = store_line_numbers
|
|
|
|
def documentClass(self) -> "Element":
|
|
self.soup.reset()
|
|
return Element(self.soup, self.soup, None)
|
|
|
|
def insertDoctype(self, token: Dict[str, Any]) -> None:
|
|
name: str = cast(str, token["name"])
|
|
publicId: Optional[str] = cast(Optional[str], token["publicId"])
|
|
systemId: Optional[str] = cast(Optional[str], token["systemId"])
|
|
|
|
doctype = Doctype.for_name_and_ids(name, publicId, systemId)
|
|
self.soup.object_was_parsed(doctype)
|
|
|
|
def elementClass(self, name: str, namespace: str) -> "Element":
|
|
sourceline: Optional[int] = None
|
|
sourcepos: Optional[int] = None
|
|
if self.parser is not None and self.store_line_numbers:
|
|
# This represents the point immediately after the end of the
|
|
# tag. We don't know when the tag started, but we do know
|
|
# where it ended -- the character just before this one.
|
|
sourceline, sourcepos = self.parser.tokenizer.stream.position()
|
|
assert sourcepos is not None
|
|
sourcepos = sourcepos - 1
|
|
tag = self.soup.new_tag(
|
|
name, namespace, sourceline=sourceline, sourcepos=sourcepos
|
|
)
|
|
|
|
return Element(tag, self.soup, namespace)
|
|
|
|
def commentClass(self, data: str) -> "TextNode":
|
|
return TextNode(Comment(data), self.soup)
|
|
|
|
def fragmentClass(self) -> "Element":
|
|
"""This is only used by html5lib HTMLParser.parseFragment(),
|
|
which is never used by Beautiful Soup, only by the html5lib
|
|
unit tests. Since we don't currently hook into those tests,
|
|
the implementation is left blank.
|
|
"""
|
|
raise NotImplementedError()
|
|
|
|
def getFragment(self) -> "Element":
|
|
"""This is only used by the html5lib unit tests. Since we
|
|
don't currently hook into those tests, the implementation is
|
|
left blank.
|
|
"""
|
|
raise NotImplementedError()
|
|
|
|
def appendChild(self, node: "Element") -> None:
|
|
# TODO: This code is not covered by the BS4 tests, and
|
|
# apparently not triggered by the html5lib test suite either.
|
|
# But it doesn't seem test-specific and there are calls to it
|
|
# (or a method with the same name) all over html5lib, so I'm
|
|
# leaving the implementation in place rather than replacing it
|
|
# with NotImplementedError()
|
|
self.soup.append(node.element)
|
|
|
|
def getDocument(self) -> "BeautifulSoup":
|
|
return self.soup
|
|
|
|
def testSerializer(self, element: "Element") -> str:
|
|
"""This is only used by the html5lib unit tests. Since we
|
|
don't currently hook into those tests, the implementation is
|
|
left blank.
|
|
"""
|
|
raise NotImplementedError()
|
|
|
|
|
|
class AttrList(object):
|
|
"""Represents a Tag's attributes in a way compatible with html5lib."""
|
|
|
|
element: Tag
|
|
attrs: _AttributeValues
|
|
|
|
def __init__(self, element: Tag):
|
|
self.element = element
|
|
self.attrs = dict(self.element.attrs)
|
|
|
|
def __iter__(self) -> Iterable[Tuple[str, _AttributeValue]]:
|
|
return list(self.attrs.items()).__iter__()
|
|
|
|
def __setitem__(self, name: str, value: _AttributeValue) -> None:
|
|
# If this attribute is a multi-valued attribute for this element,
|
|
# turn its value into a list.
|
|
list_attr = self.element.cdata_list_attributes or {}
|
|
if name in list_attr.get("*", []) or (
|
|
self.element.name in list_attr
|
|
and name in list_attr.get(self.element.name, [])
|
|
):
|
|
# A node that is being cloned may have already undergone
|
|
# this procedure. Check for this and skip it.
|
|
if not isinstance(value, list):
|
|
assert isinstance(value, str)
|
|
value = self.element.attribute_value_list_class(
|
|
nonwhitespace_re.findall(value)
|
|
)
|
|
self.element[name] = value
|
|
|
|
def items(self) -> Iterable[Tuple[str, _AttributeValue]]:
|
|
return list(self.attrs.items())
|
|
|
|
def keys(self) -> Iterable[str]:
|
|
return list(self.attrs.keys())
|
|
|
|
def __len__(self) -> int:
|
|
return len(self.attrs)
|
|
|
|
def __getitem__(self, name: str) -> _AttributeValue:
|
|
return self.attrs[name]
|
|
|
|
def __contains__(self, name: str) -> bool:
|
|
return name in list(self.attrs.keys())
|
|
|
|
|
|
class BeautifulSoupNode(treebuilder_base.Node):
|
|
element: PageElement
|
|
soup: "BeautifulSoup"
|
|
namespace: Optional[_NamespaceURL]
|
|
|
|
@property
|
|
def nodeType(self) -> int:
|
|
"""Return the html5lib constant corresponding to the type of
|
|
the underlying DOM object.
|
|
|
|
NOTE: This property is only accessed by the html5lib test
|
|
suite, not by Beautiful Soup proper.
|
|
"""
|
|
raise NotImplementedError()
|
|
|
|
# TODO-TYPING: typeshed stubs are incorrect about this;
|
|
# cloneNode returns a new Node, not None.
|
|
def cloneNode(self) -> treebuilder_base.Node:
|
|
raise NotImplementedError()
|
|
|
|
|
|
class Element(BeautifulSoupNode):
|
|
element: Tag
|
|
namespace: Optional[_NamespaceURL]
|
|
|
|
def __init__(
|
|
self, element: Tag, soup: "BeautifulSoup", namespace: Optional[_NamespaceURL]
|
|
):
|
|
treebuilder_base.Node.__init__(self, element.name)
|
|
self.element = element
|
|
self.soup = soup
|
|
self.namespace = namespace
|
|
|
|
def appendChild(self, node: "BeautifulSoupNode") -> None:
|
|
string_child: Optional[NavigableString] = None
|
|
child: PageElement
|
|
if type(node.element) is NavigableString:
|
|
string_child = child = node.element
|
|
else:
|
|
child = node.element
|
|
node.parent = self
|
|
|
|
if (
|
|
child is not None
|
|
and child.parent is not None
|
|
and not isinstance(child, str)
|
|
):
|
|
node.element.extract()
|
|
|
|
if (
|
|
string_child is not None
|
|
and self.element.contents
|
|
and type(self.element.contents[-1]) is NavigableString
|
|
):
|
|
# We are appending a string onto another string.
|
|
# TODO This has O(n^2) performance, for input like
|
|
# "a</a>a</a>a</a>..."
|
|
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) -> AttrList:
|
|
if isinstance(self.element, Comment):
|
|
return {}
|
|
return AttrList(self.element)
|
|
|
|
# An HTML5lib attribute name may either be a single string,
|
|
# or a tuple (namespace, name).
|
|
_Html5libAttributeName: TypeAlias = Union[str, Tuple[str, str]]
|
|
# Now we can define the type this method accepts as a dictionary
|
|
# mapping those attribute names to single string values.
|
|
_Html5libAttributes: TypeAlias = Dict[_Html5libAttributeName, str]
|
|
|
|
def setAttributes(self, attributes: Optional[_Html5libAttributes]) -> None:
|
|
if attributes is not None and len(attributes) > 0:
|
|
# Replace any namespaced attributes with
|
|
# NamespacedAttribute objects.
|
|
for name, value in list(attributes.items()):
|
|
if isinstance(name, tuple):
|
|
new_name = NamespacedAttribute(*name)
|
|
del attributes[name]
|
|
attributes[new_name] = value
|
|
|
|
# We can now cast attributes to the type of Dict
|
|
# used by Beautiful Soup.
|
|
normalized_attributes = cast(_AttributeValues, attributes)
|
|
|
|
# Values for tags like 'class' came in as single strings;
|
|
# replace them with lists of strings as appropriate.
|
|
self.soup.builder._replace_cdata_list_attribute_values(
|
|
self.name, normalized_attributes
|
|
)
|
|
|
|
# Then set the attributes on the Tag associated with this
|
|
# BeautifulSoupNode.
|
|
for name, value_or_values in list(normalized_attributes.items()):
|
|
self.element[name] = value_or_values
|
|
|
|
# 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: str, insertBefore: Optional["BeautifulSoupNode"] = None
|
|
) -> None:
|
|
text = TextNode(self.soup.new_string(data), self.soup)
|
|
if insertBefore:
|
|
self.insertBefore(text, insertBefore)
|
|
else:
|
|
self.appendChild(text)
|
|
|
|
def insertBefore(
|
|
self, node: "BeautifulSoupNode", refNode: "BeautifulSoupNode"
|
|
) -> None:
|
|
index = self.element.index(refNode.element)
|
|
if (
|
|
type(node.element) is NavigableString
|
|
and self.element.contents
|
|
and type(self.element.contents[index - 1]) is NavigableString
|
|
):
|
|
# (See comments in appendChild)
|
|
old_node = self.element.contents[index - 1]
|
|
assert type(old_node) is NavigableString
|
|
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: "Element") -> None:
|
|
node.element.extract()
|
|
|
|
def reparentChildren(self, new_parent: "Element") -> None:
|
|
"""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.
|
|
|
|
# We can make this assertion since we know new_parent has
|
|
# children.
|
|
assert new_parents_last_descendant is not None
|
|
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
|
|
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 is not None:
|
|
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 is not None:
|
|
new_parents_last_descendant.next_element = first_child
|
|
else:
|
|
new_parent_element.next_element = first_child
|
|
if new_parents_last_child is not None:
|
|
new_parents_last_child.next_sibling = first_child
|
|
|
|
# Find the very last element being moved. It is now the
|
|
# parent's last descendant. It has no .next_sibling and
|
|
# its .next_element is whatever the previous last
|
|
# descendant had.
|
|
last_childs_last_descendant = to_append[-1]._last_descendant(
|
|
is_initialized=False, accept_self=True
|
|
)
|
|
|
|
# Since we passed accept_self=True into _last_descendant,
|
|
# there's no possibility that the result is None.
|
|
assert last_childs_last_descendant is not None
|
|
last_childs_last_descendant.next_element = (
|
|
new_parents_last_descendant_next_element
|
|
)
|
|
if new_parents_last_descendant_next_element is not None:
|
|
# TODO-COVERAGE: This code has no test coverage and
|
|
# I'm not sure how to get html5lib to go through this
|
|
# path, but it's just the other side of the previous
|
|
# line.
|
|
new_parents_last_descendant_next_element.previous_element = (
|
|
last_childs_last_descendant
|
|
)
|
|
last_childs_last_descendant.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)
|
|
|
|
# TODO-TYPING: typeshed stubs are incorrect about this;
|
|
# hasContent returns a boolean, not None.
|
|
def hasContent(self) -> bool:
|
|
return len(self.element.contents) > 0
|
|
|
|
# TODO-TYPING: typeshed stubs are incorrect about this;
|
|
# cloneNode returns a new Node, not None.
|
|
def cloneNode(self) -> treebuilder_base.Node:
|
|
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 getNameTuple(self) -> Tuple[Optional[_NamespaceURL], str]:
|
|
if self.namespace is None:
|
|
return namespaces["html"], self.name
|
|
else:
|
|
return self.namespace, self.name
|
|
|
|
nameTuple = property(getNameTuple)
|
|
|
|
|
|
class TextNode(BeautifulSoupNode):
|
|
element: NavigableString
|
|
|
|
def __init__(self, element: NavigableString, soup: "BeautifulSoup"):
|
|
treebuilder_base.Node.__init__(self, None)
|
|
self.element = element
|
|
self.soup = soup
|