Initial Commit

lib/html5lib/serializer/__init__.py

@@ -0,0 +1,16 @@
+from __future__ import absolute_import, division, unicode_literals
+
+from .. import treewalkers
+
+from .htmlserializer import HTMLSerializer
+
+
+def serialize(input, tree="etree", format="html", encoding=None,
+              **serializer_opts):
+    # XXX: Should we cache this?
+    walker = treewalkers.getTreeWalker(tree)
+    if format == "html":
+        s = HTMLSerializer(**serializer_opts)
+    else:
+        raise ValueError("type must be html")
+    return s.render(walker(input), encoding)

lib/html5lib/serializer/htmlserializer.py

@@ -0,0 +1,320 @@
+from __future__ import absolute_import, division, unicode_literals
+from six import text_type
+
+import gettext
+_ = gettext.gettext
+
+try:
+    from functools import reduce
+except ImportError:
+    pass
+
+from ..constants import voidElements, booleanAttributes, spaceCharacters
+from ..constants import rcdataElements, entities, xmlEntities
+from .. import utils
+from xml.sax.saxutils import escape
+
+spaceCharacters = "".join(spaceCharacters)
+
+try:
+    from codecs import register_error, xmlcharrefreplace_errors
+except ImportError:
+    unicode_encode_errors = "strict"
+else:
+    unicode_encode_errors = "htmlentityreplace"
+
+    encode_entity_map = {}
+    is_ucs4 = len("\U0010FFFF") == 1
+    for k, v in list(entities.items()):
+        # skip multi-character entities
+        if ((is_ucs4 and len(v) > 1) or
+                (not is_ucs4 and len(v) > 2)):
+            continue
+        if v != "&":
+            if len(v) == 2:
+                v = utils.surrogatePairToCodepoint(v)
+            else:
+                v = ord(v)
+            if not v in encode_entity_map or k.islower():
+                # prefer < over < and similarly for &, >, etc.
+                encode_entity_map[v] = k
+
+    def htmlentityreplace_errors(exc):
+        if isinstance(exc, (UnicodeEncodeError, UnicodeTranslateError)):
+            res = []
+            codepoints = []
+            skip = False
+            for i, c in enumerate(exc.object[exc.start:exc.end]):
+                if skip:
+                    skip = False
+                    continue
+                index = i + exc.start
+                if utils.isSurrogatePair(exc.object[index:min([exc.end, index + 2])]):
+                    codepoint = utils.surrogatePairToCodepoint(exc.object[index:index + 2])
+                    skip = True
+                else:
+                    codepoint = ord(c)
+                codepoints.append(codepoint)
+            for cp in codepoints:
+                e = encode_entity_map.get(cp)
+                if e:
+                    res.append("&")
+                    res.append(e)
+                    if not e.endswith(";"):
+                        res.append(";")
+                else:
+                    res.append("&#x%s;" % (hex(cp)[2:]))
+            return ("".join(res), exc.end)
+        else:
+            return xmlcharrefreplace_errors(exc)
+
+    register_error(unicode_encode_errors, htmlentityreplace_errors)
+
+    del register_error
+
+
+class HTMLSerializer(object):
+
+    # attribute quoting options
+    quote_attr_values = False
+    quote_char = '"'
+    use_best_quote_char = True
+
+    # tag syntax options
+    omit_optional_tags = True
+    minimize_boolean_attributes = True
+    use_trailing_solidus = False
+    space_before_trailing_solidus = True
+
+    # escaping options
+    escape_lt_in_attrs = False
+    escape_rcdata = False
+    resolve_entities = True
+
+    # miscellaneous options
+    alphabetical_attributes = False
+    inject_meta_charset = True
+    strip_whitespace = False
+    sanitize = False
+
+    options = ("quote_attr_values", "quote_char", "use_best_quote_char",
+               "omit_optional_tags", "minimize_boolean_attributes",
+               "use_trailing_solidus", "space_before_trailing_solidus",
+               "escape_lt_in_attrs", "escape_rcdata", "resolve_entities",
+               "alphabetical_attributes", "inject_meta_charset",
+               "strip_whitespace", "sanitize")
+
+    def __init__(self, **kwargs):
+        """Initialize HTMLSerializer.
+
+        Keyword options (default given first unless specified) include:
+
+        inject_meta_charset=True|False
+          Whether it insert a meta element to define the character set of the
+          document.
+        quote_attr_values=True|False
+          Whether to quote attribute values that don't require quoting
+          per HTML5 parsing rules.
+        quote_char=u'"'|u"'"
+          Use given quote character for attribute quoting. Default is to
+          use double quote unless attribute value contains a double quote,
+          in which case single quotes are used instead.
+        escape_lt_in_attrs=False|True
+          Whether to escape < in attribute values.
+        escape_rcdata=False|True
+          Whether to escape characters that need to be escaped within normal
+          elements within rcdata elements such as style.
+        resolve_entities=True|False
+          Whether to resolve named character entities that appear in the
+          source tree. The XML predefined entities &lt; &gt; &amp; &quot; &apos;
+          are unaffected by this setting.
+        strip_whitespace=False|True
+          Whether to remove semantically meaningless whitespace. (This
+          compresses all whitespace to a single space except within pre.)
+        minimize_boolean_attributes=True|False
+          Shortens boolean attributes to give just the attribute value,
+          for example <input disabled="disabled"> becomes <input disabled>.
+        use_trailing_solidus=False|True
+          Includes a close-tag slash at the end of the start tag of void
+          elements (empty elements whose end tag is forbidden). E.g. <hr/>.
+        space_before_trailing_solidus=True|False
+          Places a space immediately before the closing slash in a tag
+          using a trailing solidus. E.g. <hr />. Requires use_trailing_solidus.
+        sanitize=False|True
+          Strip all unsafe or unknown constructs from output.
+          See `html5lib user documentation`_
+        omit_optional_tags=True|False
+          Omit start/end tags that are optional.
+        alphabetical_attributes=False|True
+          Reorder attributes to be in alphabetical order.
+
+        .. _html5lib user documentation: http://code.google.com/p/html5lib/wiki/UserDocumentation
+        """
+        if 'quote_char' in kwargs:
+            self.use_best_quote_char = False
+        for attr in self.options:
+            setattr(self, attr, kwargs.get(attr, getattr(self, attr)))
+        self.errors = []
+        self.strict = False
+
+    def encode(self, string):
+        assert(isinstance(string, text_type))
+        if self.encoding:
+            return string.encode(self.encoding, unicode_encode_errors)
+        else:
+            return string
+
+    def encodeStrict(self, string):
+        assert(isinstance(string, text_type))
+        if self.encoding:
+            return string.encode(self.encoding, "strict")
+        else:
+            return string
+
+    def serialize(self, treewalker, encoding=None):
+        self.encoding = encoding
+        in_cdata = False
+        self.errors = []
+
+        if encoding and self.inject_meta_charset:
+            from ..filters.inject_meta_charset import Filter
+            treewalker = Filter(treewalker, encoding)
+        # WhitespaceFilter should be used before OptionalTagFilter
+        # for maximum efficiently of this latter filter
+        if self.strip_whitespace:
+            from ..filters.whitespace import Filter
+            treewalker = Filter(treewalker)
+        if self.sanitize:
+            from ..filters.sanitizer import Filter
+            treewalker = Filter(treewalker)
+        if self.omit_optional_tags:
+            from ..filters.optionaltags import Filter
+            treewalker = Filter(treewalker)
+        # Alphabetical attributes must be last, as other filters
+        # could add attributes and alter the order
+        if self.alphabetical_attributes:
+            from ..filters.alphabeticalattributes import Filter
+            treewalker = Filter(treewalker)
+
+        for token in treewalker:
+            type = token["type"]
+            if type == "Doctype":
+                doctype = "<!DOCTYPE %s" % token["name"]
+
+                if token["publicId"]:
+                    doctype += ' PUBLIC "%s"' % token["publicId"]
+                elif token["systemId"]:
+                    doctype += " SYSTEM"
+                if token["systemId"]:
+                    if token["systemId"].find('"') >= 0:
+                        if token["systemId"].find("'") >= 0:
+                            self.serializeError(_("System identifer contains both single and double quote characters"))
+                        quote_char = "'"
+                    else:
+                        quote_char = '"'
+                    doctype += " %s%s%s" % (quote_char, token["systemId"], quote_char)
+
+                doctype += ">"
+                yield self.encodeStrict(doctype)
+
+            elif type in ("Characters", "SpaceCharacters"):
+                if type == "SpaceCharacters" or in_cdata:
+                    if in_cdata and token["data"].find("</") >= 0:
+                        self.serializeError(_("Unexpected </ in CDATA"))
+                    yield self.encode(token["data"])
+                else:
+                    yield self.encode(escape(token["data"]))
+
+            elif type in ("StartTag", "EmptyTag"):
+                name = token["name"]
+                yield self.encodeStrict("<%s" % name)
+                if name in rcdataElements and not self.escape_rcdata:
+                    in_cdata = True
+                elif in_cdata:
+                    self.serializeError(_("Unexpected child element of a CDATA element"))
+                for (attr_namespace, attr_name), attr_value in token["data"].items():
+                    # TODO: Add namespace support here
+                    k = attr_name
+                    v = attr_value
+                    yield self.encodeStrict(' ')
+
+                    yield self.encodeStrict(k)
+                    if not self.minimize_boolean_attributes or \
+                        (k not in booleanAttributes.get(name, tuple())
+                         and k not in booleanAttributes.get("", tuple())):
+                        yield self.encodeStrict("=")
+                        if self.quote_attr_values or not v:
+                            quote_attr = True
+                        else:
+                            quote_attr = reduce(lambda x, y: x or (y in v),
+                                                spaceCharacters + ">\"'=", False)
+                        v = v.replace("&", "&amp;")
+                        if self.escape_lt_in_attrs:
+                            v = v.replace("<", "&lt;")
+                        if quote_attr:
+                            quote_char = self.quote_char
+                            if self.use_best_quote_char:
+                                if "'" in v and '"' not in v:
+                                    quote_char = '"'
+                                elif '"' in v and "'" not in v:
+                                    quote_char = "'"
+                            if quote_char == "'":
+                                v = v.replace("'", "&#39;")
+                            else:
+                                v = v.replace('"', "&quot;")
+                            yield self.encodeStrict(quote_char)
+                            yield self.encode(v)
+                            yield self.encodeStrict(quote_char)
+                        else:
+                            yield self.encode(v)
+                if name in voidElements and self.use_trailing_solidus:
+                    if self.space_before_trailing_solidus:
+                        yield self.encodeStrict(" /")
+                    else:
+                        yield self.encodeStrict("/")
+                yield self.encode(">")
+
+            elif type == "EndTag":
+                name = token["name"]
+                if name in rcdataElements:
+                    in_cdata = False
+                elif in_cdata:
+                    self.serializeError(_("Unexpected child element of a CDATA element"))
+                yield self.encodeStrict("</%s>" % name)
+
+            elif type == "Comment":
+                data = token["data"]
+                if data.find("--") >= 0:
+                    self.serializeError(_("Comment contains --"))
+                yield self.encodeStrict("<!--%s-->" % token["data"])
+
+            elif type == "Entity":
+                name = token["name"]
+                key = name + ";"
+                if not key in entities:
+                    self.serializeError(_("Entity %s not recognized" % name))
+                if self.resolve_entities and key not in xmlEntities:
+                    data = entities[key]
+                else:
+                    data = "&%s;" % name
+                yield self.encodeStrict(data)
+
+            else:
+                self.serializeError(token["data"])
+
+    def render(self, treewalker, encoding=None):
+        if encoding:
+            return b"".join(list(self.serialize(treewalker, encoding)))
+        else:
+            return "".join(list(self.serialize(treewalker)))
+
+    def serializeError(self, data="XXX ERROR MESSAGE NEEDED"):
+        # XXX The idea is to make data mandatory.
+        self.errors.append(data)
+        if self.strict:
+            raise SerializeError
+
+
+def SerializeError(Exception):
+    """Error in serialized tree"""
+    pass