aboutsummaryrefslogtreecommitdiffstats
path: root/lib/bs4/builder/_html5lib.py
blob: 0f4007a9bde157ef115f8ad513c150ed22ff96da (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
__all__ = [
    'HTML5TreeBuilder',
    ]

import warnings
from bs4.builder import (
    PERMISSIVE,
    HTML,
    HTML_5,
    HTMLTreeBuilder,
    )
from bs4.element import NamespacedAttribute
import html5lib
try:
    # html5lib >= 0.99999999/1.0b9
    from html5lib.treebuilders import base as treebuildersbase
except ImportError:
    # html5lib <= 0.9999999/1.0b8
    from html5lib.treebuilders import _base as treebuildersbase
from html5lib.constants import namespaces

from bs4.element import (
    Comment,
    Doctype,
    NavigableString,
    Tag,
    )

class HTML5TreeBuilder(HTMLTreeBuilder):
    """Use html5lib to build a tree."""

    features = ['html5lib', PERMISSIVE, HTML_5, HTML]

    def prepare_markup(self, markup, user_specified_encoding):
        # Store the user-specified encoding for use later on.
        self.user_specified_encoding = user_specified_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, unicode):
            # 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 u'<html><head></head><body>%s</body></html>' % fragment


class TreeBuilderForHtml5lib(treebuildersbase.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 treebuildersbase.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):
        "set attr", name, 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(treebuildersbase.Node):
    def __init__(self, element, soup, namespace):
        treebuildersbase.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, basestring):
            # 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, basestring) 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
            # "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, basestring):
                # 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)
            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 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."""
        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]
            first_child.previous_element = new_parents_last_descendant
            first_child.previous_sibling = new_parents_last_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
            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

    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):
        treebuildersbase.Node.__init__(self, None)
        self.element = element
        self.soup = soup

    def cloneNode(self):
        raise NotImplementedError