summaryrefslogtreecommitdiff
path: root/element.py
diff options
context:
space:
mode:
Diffstat (limited to 'element.py')
-rw-r--r--element.py851
1 files changed, 851 insertions, 0 deletions
diff --git a/element.py b/element.py
new file mode 100644
index 0000000..7649b4c
--- /dev/null
+++ b/element.py
@@ -0,0 +1,851 @@
+import re
+import types
+try:
+ from htmlentitydefs import name2codepoint
+except ImportError:
+ name2codepoint = {}
+
+from util import isString, isList
+
+DEFAULT_OUTPUT_ENCODING = "utf-8"
+
+class Entities:
+ """A mixin class that knows about XML entities."""
+
+ HTML_ENTITIES = "html"
+ XML_ENTITIES = "xml"
+ XHTML_ENTITIES = "xhtml"
+
+ def _invert(h):
+ "Cheap function to invert a hash."
+ i = {}
+ for k,v in h.items():
+ i[v] = k
+ return i
+
+ XML_ENTITIES_TO_SPECIAL_CHARS = { "apos" : "'",
+ "quot" : '"',
+ "amp" : "&",
+ "lt" : "<",
+ "gt" : ">" }
+
+ XML_SPECIAL_CHARS_TO_ENTITIES = _invert(XML_ENTITIES_TO_SPECIAL_CHARS)
+
+class PageElement:
+ """Contains the navigational information for some part of the page
+ (either a tag or a piece of text)"""
+
+ def setup(self, parent=None, previous=None):
+ """Sets up the initial relations between this element and
+ other elements."""
+ self.parent = parent
+ self.previous = previous
+ self.next = None
+ self.previousSibling = None
+ self.nextSibling = None
+ if self.parent and self.parent.contents:
+ self.previousSibling = self.parent.contents[-1]
+ self.previousSibling.nextSibling = self
+
+ def replaceWith(self, replaceWith):
+ oldParent = self.parent
+ myIndex = self.parent.contents.index(self)
+ if hasattr(replaceWith, 'parent') and replaceWith.parent == self.parent:
+ # We're replacing this element with one of its siblings.
+ index = self.parent.contents.index(replaceWith)
+ if index and index < myIndex:
+ # Furthermore, it comes before this element. That
+ # means that when we extract it, the index of this
+ # element will change.
+ myIndex = myIndex - 1
+ self.extract()
+ oldParent.insert(myIndex, replaceWith)
+
+ def extract(self):
+ """Destructively rips this element out of the tree."""
+ if self.parent:
+ try:
+ self.parent.contents.remove(self)
+ except ValueError:
+ pass
+
+ #Find the two elements that would be next to each other if
+ #this element (and any children) hadn't been parsed. Connect
+ #the two.
+ lastChild = self._lastRecursiveChild()
+ nextElement = lastChild.next
+
+ if self.previous:
+ self.previous.next = nextElement
+ if nextElement:
+ nextElement.previous = self.previous
+ self.previous = None
+ lastChild.next = None
+
+ self.parent = None
+ if self.previousSibling:
+ self.previousSibling.nextSibling = self.nextSibling
+ if self.nextSibling:
+ self.nextSibling.previousSibling = self.previousSibling
+ self.previousSibling = self.nextSibling = None
+ return self
+
+ def _lastRecursiveChild(self):
+ "Finds the last element beneath this object to be parsed."
+ lastChild = self
+ while hasattr(lastChild, 'contents') and lastChild.contents:
+ lastChild = lastChild.contents[-1]
+ return lastChild
+
+ def insert(self, position, newChild):
+ if (isinstance(newChild, basestring)
+ or isinstance(newChild, unicode)) \
+ and not isinstance(newChild, NavigableString):
+ newChild = NavigableString(newChild)
+
+ position = min(position, len(self.contents))
+ if hasattr(newChild, 'parent') and newChild.parent != None:
+ # We're 'inserting' an element that's already one
+ # of this object's children.
+ if newChild.parent == self:
+ index = self.find(newChild)
+ if index and index < position:
+ # Furthermore we're moving it further down the
+ # list of this object's children. That means that
+ # when we extract this element, our target index
+ # will jump down one.
+ position = position - 1
+ newChild.extract()
+
+ newChild.parent = self
+ previousChild = None
+ if position == 0:
+ newChild.previousSibling = None
+ newChild.previous = self
+ else:
+ previousChild = self.contents[position-1]
+ newChild.previousSibling = previousChild
+ newChild.previousSibling.nextSibling = newChild
+ newChild.previous = previousChild._lastRecursiveChild()
+ if newChild.previous:
+ newChild.previous.next = newChild
+
+ newChildsLastElement = newChild._lastRecursiveChild()
+
+ if position >= len(self.contents):
+ newChild.nextSibling = None
+
+ parent = self
+ parentsNextSibling = None
+ while not parentsNextSibling:
+ parentsNextSibling = parent.nextSibling
+ parent = parent.parent
+ if not parent: # This is the last element in the document.
+ break
+ if parentsNextSibling:
+ newChildsLastElement.next = parentsNextSibling
+ else:
+ newChildsLastElement.next = None
+ else:
+ nextChild = self.contents[position]
+ newChild.nextSibling = nextChild
+ if newChild.nextSibling:
+ newChild.nextSibling.previousSibling = newChild
+ newChildsLastElement.next = nextChild
+
+ if newChildsLastElement.next:
+ newChildsLastElement.next.previous = newChildsLastElement
+ self.contents.insert(position, newChild)
+
+ def append(self, tag):
+ """Appends the given tag to the contents of this tag."""
+ self.insert(len(self.contents), tag)
+
+ def findNext(self, name=None, attrs={}, text=None, **kwargs):
+ """Returns the first item that matches the given criteria and
+ appears after this Tag in the document."""
+ return self._findOne(self.findAllNext, name, attrs, text, **kwargs)
+
+ def findAllNext(self, name=None, attrs={}, text=None, limit=None,
+ **kwargs):
+ """Returns all items that match the given criteria and appear
+ after this Tag in the document."""
+ return self._findAll(name, attrs, text, limit, self.nextGenerator,
+ **kwargs)
+
+ def findNextSibling(self, name=None, attrs={}, text=None, **kwargs):
+ """Returns the closest sibling to this Tag that matches the
+ given criteria and appears after this Tag in the document."""
+ return self._findOne(self.findNextSiblings, name, attrs, text,
+ **kwargs)
+
+ def findNextSiblings(self, name=None, attrs={}, text=None, limit=None,
+ **kwargs):
+ """Returns the siblings of this Tag that match the given
+ criteria and appear after this Tag in the document."""
+ return self._findAll(name, attrs, text, limit,
+ self.nextSiblingGenerator, **kwargs)
+ fetchNextSiblings = findNextSiblings # Compatibility with pre-3.x
+
+ def findPrevious(self, name=None, attrs={}, text=None, **kwargs):
+ """Returns the first item that matches the given criteria and
+ appears before this Tag in the document."""
+ return self._findOne(self.findAllPrevious, name, attrs, text, **kwargs)
+
+ def findAllPrevious(self, name=None, attrs={}, text=None, limit=None,
+ **kwargs):
+ """Returns all items that match the given criteria and appear
+ before this Tag in the document."""
+ return self._findAll(name, attrs, text, limit, self.previousGenerator,
+ **kwargs)
+ fetchPrevious = findAllPrevious # Compatibility with pre-3.x
+
+ def findPreviousSibling(self, name=None, attrs={}, text=None, **kwargs):
+ """Returns the closest sibling to this Tag that matches the
+ given criteria and appears before this Tag in the document."""
+ return self._findOne(self.findPreviousSiblings, name, attrs, text,
+ **kwargs)
+
+ def findPreviousSiblings(self, name=None, attrs={}, text=None,
+ limit=None, **kwargs):
+ """Returns the siblings of this Tag that match the given
+ criteria and appear before this Tag in the document."""
+ return self._findAll(name, attrs, text, limit,
+ self.previousSiblingGenerator, **kwargs)
+ fetchPreviousSiblings = findPreviousSiblings # Compatibility with pre-3.x
+
+ def findParent(self, name=None, attrs={}, **kwargs):
+ """Returns the closest parent of this Tag that matches the given
+ criteria."""
+ # NOTE: We can't use _findOne because findParents takes a different
+ # set of arguments.
+ r = None
+ l = self.findParents(name, attrs, 1)
+ if l:
+ r = l[0]
+ return r
+
+ def findParents(self, name=None, attrs={}, limit=None, **kwargs):
+ """Returns the parents of this Tag that match the given
+ criteria."""
+
+ return self._findAll(name, attrs, None, limit, self.parentGenerator,
+ **kwargs)
+ fetchParents = findParents # Compatibility with pre-3.x
+
+ #These methods do the real heavy lifting.
+
+ def _findOne(self, method, name, attrs, text, **kwargs):
+ r = None
+ l = method(name, attrs, text, 1, **kwargs)
+ if l:
+ r = l[0]
+ return r
+
+ def _findAll(self, name, attrs, text, limit, generator, **kwargs):
+ "Iterates over a generator looking for things that match."
+
+ if isinstance(name, SoupStrainer):
+ strainer = name
+ else:
+ # Build a SoupStrainer
+ strainer = SoupStrainer(name, attrs, text, **kwargs)
+ results = ResultSet(strainer)
+ g = generator()
+ while True:
+ try:
+ i = g.next()
+ except StopIteration:
+ break
+ if i:
+ found = strainer.search(i)
+ if found:
+ results.append(found)
+ if limit and len(results) >= limit:
+ break
+ return results
+
+ #These Generators can be used to navigate starting from both
+ #NavigableStrings and Tags.
+ def nextGenerator(self):
+ i = self
+ while i:
+ i = i.next
+ yield i
+
+ def nextSiblingGenerator(self):
+ i = self
+ while i:
+ i = i.nextSibling
+ yield i
+
+ def previousGenerator(self):
+ i = self
+ while i:
+ i = i.previous
+ yield i
+
+ def previousSiblingGenerator(self):
+ i = self
+ while i:
+ i = i.previousSibling
+ yield i
+
+ def parentGenerator(self):
+ i = self
+ while i:
+ i = i.parent
+ yield i
+
+ # Utility methods
+ def substituteEncoding(self, str, encoding=None):
+ encoding = encoding or "utf-8"
+ return str.replace("%SOUP-ENCODING%", encoding)
+
+ def toEncoding(self, s, encoding=None):
+ """Encodes an object to a string in some encoding, or to Unicode.
+ ."""
+ if isinstance(s, unicode):
+ if encoding:
+ s = s.encode(encoding)
+ elif isinstance(s, str):
+ if encoding:
+ s = s.encode(encoding)
+ else:
+ s = unicode(s)
+ else:
+ if encoding:
+ s = self.toEncoding(str(s), encoding)
+ else:
+ s = unicode(s)
+ return s
+
+class NavigableString(unicode, PageElement):
+
+ def __new__(cls, value):
+ """Create a new NavigableString.
+
+ When unpickling a NavigableString, this method is called with
+ the string in DEFAULT_OUTPUT_ENCODING. That encoding needs to be
+ passed in to the superclass's __new__ or the superclass won't know
+ how to handle non-ASCII characters.
+ """
+ if isinstance(value, unicode):
+ return unicode.__new__(cls, value)
+ return unicode.__new__(cls, value, DEFAULT_OUTPUT_ENCODING)
+
+ def __getnewargs__(self):
+ return (unicode(self),)
+
+ def __getattr__(self, attr):
+ """text.string gives you text. This is for backwards
+ compatibility for Navigable*String, but for CData* it lets you
+ get the string without the CData wrapper."""
+ if attr == 'string':
+ return self
+ else:
+ raise AttributeError, "'%s' object has no attribute '%s'" % (self.__class__.__name__, attr)
+
+ def encode(self, encoding=DEFAULT_OUTPUT_ENCODING):
+ return self.decode().encode(encoding)
+
+ def decodeGivenEventualEncoding(self, eventualEncoding):
+ return self
+
+class CData(NavigableString):
+
+ def decodeGivenEventualEncoding(self, eventualEncoding):
+ return u'<![CDATA[' + self + u']]>'
+
+class ProcessingInstruction(NavigableString):
+
+ def decodeGivenEventualEncoding(self, eventualEncoding):
+ output = self
+ if u'%SOUP-ENCODING%' in output:
+ output = self.substituteEncoding(output, eventualEncoding)
+ return u'<?' + output + u'?>'
+
+class Comment(NavigableString):
+ def decodeGivenEventualEncoding(self, eventualEncoding):
+ return u'<!--' + self + u'-->'
+
+class Declaration(NavigableString):
+ def decodeGivenEventualEncoding(self, eventualEncoding):
+ return u'<!' + self + u'>'
+
+class Tag(PageElement, Entities):
+
+ """Represents a found HTML tag with its attributes and contents."""
+
+ def _convertEntities(self, builder, match):
+ """Used in a call to re.sub to replace HTML, XML, and numeric
+ entities with the appropriate Unicode characters. If HTML
+ entities are being converted, any unrecognized entities are
+ escaped."""
+ x = match.group(1)
+ if builder.convert_html_entities and x in name2codepoint:
+ return unichr(name2codepoint[x])
+ elif x in self.XML_ENTITIES_TO_SPECIAL_CHARS:
+ if builder.convert_xml_entities:
+ return self.XML_ENTITIES_TO_SPECIAL_CHARS[x]
+ else:
+ return u'&%s;' % x
+ elif len(x) > 0 and x[0] == '#':
+ # Handle numeric entities
+ if len(x) > 1 and x[1] == 'x':
+ return unichr(int(x[2:], 16))
+ else:
+ return unichr(int(x[1:]))
+
+ elif self.escapeUnrecognizedEntities:
+ return u'&amp;%s;' % x
+ else:
+ return u'&%s;' % x
+
+ def __init__(self, parser, builder, name, attrs=None, parent=None,
+ previous=None):
+ "Basic constructor."
+
+ # We don't actually store the parser object: that lets extracted
+ # chunks be garbage-collected
+ self.parserClass = parser.__class__
+ self.name = name
+ self.isSelfClosing = builder.isSelfClosingTag(name)
+ if attrs == None:
+ attrs = []
+ if isinstance(attrs, types.DictType):
+ self.attrMap = attrs
+ self.attrs = attrs
+ self.contents = []
+ self.setup(parent, previous)
+ self.hidden = False
+ self.containsSubstitutions = False
+ self.escapeUnrecognizedEntities = parser.escapeUnrecognizedEntities
+
+ # Convert any HTML, XML, or numeric entities in the attribute values.
+ convert_one = lambda x: self._convertEntities(parser.builder, x)
+ def convert(kval):
+ k, val = kval
+ if val is None:
+ return kval
+ return (k, re.sub("&(#\d+|#x[0-9a-fA-F]+|\w+);", convert_one, val))
+ if isinstance(attrs, types.DictType):
+ self.attrs = [convert(kv) for kv in attrs.items()]
+ else:
+ self.attrs = map(convert, attrs)
+
+ def get(self, key, default=None):
+ """Returns the value of the 'key' attribute for the tag, or
+ the value given for 'default' if it doesn't have that
+ attribute."""
+ return self._getAttrMap().get(key, default)
+
+ def has_key(self, key):
+ return self._getAttrMap().has_key(key)
+
+ def __getitem__(self, key):
+ """tag[key] returns the value of the 'key' attribute for the tag,
+ and throws an exception if it's not there."""
+ return self._getAttrMap()[key]
+
+ def __iter__(self):
+ "Iterating over a tag iterates over its contents."
+ return iter(self.contents)
+
+ def __len__(self):
+ "The length of a tag is the length of its list of contents."
+ return len(self.contents)
+
+ def __contains__(self, x):
+ return x in self.contents
+
+ def __nonzero__(self):
+ "A tag is non-None even if it has no contents."
+ return True
+
+ def __setitem__(self, key, value):
+ """Setting tag[key] sets the value of the 'key' attribute for the
+ tag."""
+ self._getAttrMap()
+ self.attrMap[key] = value
+ found = False
+ for i in range(0, len(self.attrs)):
+ if self.attrs[i][0] == key:
+ self.attrs[i] = (key, value)
+ found = True
+ if not found:
+ self.attrs.append((key, value))
+ self._getAttrMap()[key] = value
+
+ def __delitem__(self, key):
+ "Deleting tag[key] deletes all 'key' attributes for the tag."
+ for item in self.attrs:
+ if item[0] == key:
+ self.attrs.remove(item)
+ #We don't break because bad HTML can define the same
+ #attribute multiple times.
+ self._getAttrMap()
+ if self.attrMap.has_key(key):
+ del self.attrMap[key]
+
+ def __call__(self, *args, **kwargs):
+ """Calling a tag like a function is the same as calling its
+ findAll() method. Eg. tag('a') returns a list of all the A tags
+ found within this tag."""
+ return apply(self.findAll, args, kwargs)
+
+ def __getattr__(self, tag):
+ #print "Getattr %s.%s" % (self.__class__, tag)
+ if len(tag) > 3 and tag.rfind('Tag') == len(tag)-3:
+ return self.find(tag[:-3])
+ elif tag.find('__') != 0:
+ return self.find(tag)
+ raise AttributeError, "'%s' object has no attribute '%s'" % (self.__class__, tag)
+
+ def __eq__(self, other):
+ """Returns true iff this tag has the same name, the same attributes,
+ and the same contents (recursively) as the given tag.
+
+ NOTE: right now this will return false if two tags have the
+ same attributes in a different order. Should this be fixed?"""
+ if not hasattr(other, 'name') or not hasattr(other, 'attrs') or not hasattr(other, 'contents') or self.name != other.name or self.attrs != other.attrs or len(self) != len(other):
+ return False
+ for i in range(0, len(self.contents)):
+ if self.contents[i] != other.contents[i]:
+ return False
+ return True
+
+ def __ne__(self, other):
+ """Returns true iff this tag is not identical to the other tag,
+ as defined in __eq__."""
+ return not self == other
+
+ def __repr__(self, encoding=DEFAULT_OUTPUT_ENCODING):
+ """Renders this tag as a string."""
+ return self.decode(eventualEncoding=encoding)
+
+ BARE_AMPERSAND_OR_BRACKET = re.compile("([<>]|"
+ + "&(?!#\d+;|#x[0-9a-fA-F]+;|\w+;)"
+ + ")")
+
+ def _sub_entity(self, x):
+ """Used with a regular expression to substitute the
+ appropriate XML entity for an XML special character."""
+ return "&" + self.XML_SPECIAL_CHARS_TO_ENTITIES[x.group(0)[0]] + ";"
+
+ def __unicode__(self):
+ return self.decode()
+
+ def __str__(self):
+ return self.encode()
+
+ def encode(self, encoding=DEFAULT_OUTPUT_ENCODING,
+ prettyPrint=False, indentLevel=0):
+ return self.decode(prettyPrint, indentLevel, encoding).encode(encoding)
+
+ def decode(self, prettyPrint=False, indentLevel=0,
+ eventualEncoding=DEFAULT_OUTPUT_ENCODING):
+ """Returns a string or Unicode representation of this tag and
+ its contents. To get Unicode, pass None for encoding."""
+
+ attrs = []
+ if self.attrs:
+ for key, val in self.attrs:
+ fmt = '%s="%s"'
+ if isString(val):
+ if (self.containsSubstitutions
+ and eventualEncoding is not None
+ and '%SOUP-ENCODING%' in val):
+ val = self.substituteEncoding(val, eventualEncoding)
+
+ # The attribute value either:
+ #
+ # * Contains no embedded double quotes or single quotes.
+ # No problem: we enclose it in double quotes.
+ # * Contains embedded single quotes. No problem:
+ # double quotes work here too.
+ # * Contains embedded double quotes. No problem:
+ # we enclose it in single quotes.
+ # * Embeds both single _and_ double quotes. This
+ # can't happen naturally, but it can happen if
+ # you modify an attribute value after parsing
+ # the document. Now we have a bit of a
+ # problem. We solve it by enclosing the
+ # attribute in single quotes, and escaping any
+ # embedded single quotes to XML entities.
+ if '"' in val:
+ fmt = "%s='%s'"
+ if "'" in val:
+ # TODO: replace with apos when
+ # appropriate.
+ val = val.replace("'", "&squot;")
+
+ # Now we're okay w/r/t quotes. But the attribute
+ # value might also contain angle brackets, or
+ # ampersands that aren't part of entities. We need
+ # to escape those to XML entities too.
+ val = self.BARE_AMPERSAND_OR_BRACKET.sub(self._sub_entity, val)
+ if val is None:
+ # Handle boolean attributes.
+ decoded = key
+ else:
+ decoded = fmt % (key, val)
+ attrs.append(decoded)
+ close = ''
+ closeTag = ''
+ if self.isSelfClosing:
+ close = ' /'
+ else:
+ closeTag = '</%s>' % self.name
+
+ indentTag, indentContents = 0, 0
+ if prettyPrint:
+ indentTag = indentLevel
+ space = (' ' * (indentTag-1))
+ indentContents = indentTag + 1
+ contents = self.decodeContents(prettyPrint, indentContents,
+ eventualEncoding)
+ if self.hidden:
+ s = contents
+ else:
+ s = []
+ attributeString = ''
+ if attrs:
+ attributeString = ' ' + ' '.join(attrs)
+ if prettyPrint:
+ s.append(space)
+ s.append('<%s%s%s>' % (self.name, attributeString, close))
+ if prettyPrint:
+ s.append("\n")
+ s.append(contents)
+ if prettyPrint and contents and contents[-1] != "\n":
+ s.append("\n")
+ if prettyPrint and closeTag:
+ s.append(space)
+ s.append(closeTag)
+ if prettyPrint and closeTag and self.nextSibling:
+ s.append("\n")
+ s = ''.join(s)
+ return s
+
+ def decompose(self):
+ """Recursively destroys the contents of this tree."""
+ contents = [i for i in self.contents]
+ for i in contents:
+ if isinstance(i, Tag):
+ i.decompose()
+ else:
+ i.extract()
+ self.extract()
+
+ def prettify(self, encoding=DEFAULT_OUTPUT_ENCODING):
+ return self.encode(encoding, True)
+
+ def encodeContents(self, encoding=DEFAULT_OUTPUT_ENCODING,
+ prettyPrint=False, indentLevel=0):
+ return self.decodeContents(prettyPrint, indentLevel).encode(encoding)
+
+ def decodeContents(self, prettyPrint=False, indentLevel=0,
+ eventualEncoding=DEFAULT_OUTPUT_ENCODING):
+ """Renders the contents of this tag as a string in the given
+ encoding. If encoding is None, returns a Unicode string.."""
+ s=[]
+ for c in self:
+ text = None
+ if isinstance(c, NavigableString):
+ text = c.decodeGivenEventualEncoding(eventualEncoding)
+ elif isinstance(c, Tag):
+ s.append(c.decode(prettyPrint, indentLevel, eventualEncoding))
+ if text and prettyPrint:
+ text = text.strip()
+ if text:
+ if prettyPrint:
+ s.append(" " * (indentLevel-1))
+ s.append(text)
+ if prettyPrint:
+ s.append("\n")
+ return ''.join(s)
+
+ #Soup methods
+
+ def find(self, name=None, attrs={}, recursive=True, text=None,
+ **kwargs):
+ """Return only the first child of this Tag matching the given
+ criteria."""
+ r = None
+ l = self.findAll(name, attrs, recursive, text, 1, **kwargs)
+ if l:
+ r = l[0]
+ return r
+ findChild = find
+
+ def findAll(self, name=None, attrs={}, recursive=True, text=None,
+ limit=None, **kwargs):
+ """Extracts a list of Tag objects that match the given
+ criteria. You can specify the name of the Tag and any
+ attributes you want the Tag to have.
+
+ The value of a key-value pair in the 'attrs' map can be a
+ string, a list of strings, a regular expression object, or a
+ callable that takes a string and returns whether or not the
+ string matches for some custom definition of 'matches'. The
+ same is true of the tag name."""
+ generator = self.recursiveChildGenerator
+ if not recursive:
+ generator = self.childGenerator
+ return self._findAll(name, attrs, text, limit, generator, **kwargs)
+ findChildren = findAll
+
+ #Private methods
+
+ def _getAttrMap(self):
+ """Initializes a map representation of this tag's attributes,
+ if not already initialized."""
+ if not getattr(self, 'attrMap'):
+ self.attrMap = {}
+ for (key, value) in self.attrs:
+ self.attrMap[key] = value
+ return self.attrMap
+
+ #Generator methods
+ def childGenerator(self):
+ for i in range(0, len(self.contents)):
+ yield self.contents[i]
+ raise StopIteration
+
+ def recursiveChildGenerator(self):
+ if not len(self.contents):
+ raise StopIteration
+ stopNode = self._lastRecursiveChild().next
+ current = self.contents[0]
+ while current is not stopNode:
+ yield current
+ current = current.next
+
+# Next, a couple classes to represent queries and their results.
+class SoupStrainer:
+ """Encapsulates a number of ways of matching a markup element (tag or
+ text)."""
+
+ def __init__(self, name=None, attrs={}, text=None, **kwargs):
+ self.name = name
+ if isString(attrs):
+ kwargs['class'] = attrs
+ attrs = None
+ if kwargs:
+ if attrs:
+ attrs = attrs.copy()
+ attrs.update(kwargs)
+ else:
+ attrs = kwargs
+ self.attrs = attrs
+ self.text = text
+
+ def __str__(self):
+ if self.text:
+ return self.text
+ else:
+ return "%s|%s" % (self.name, self.attrs)
+
+ def searchTag(self, markupName=None, markupAttrs={}):
+ found = None
+ markup = None
+ if isinstance(markupName, Tag):
+ markup = markupName
+ markupAttrs = markup
+ callFunctionWithTagData = callable(self.name) \
+ and not isinstance(markupName, Tag)
+
+ if (not self.name) \
+ or callFunctionWithTagData \
+ or (markup and self._matches(markup, self.name)) \
+ or (not markup and self._matches(markupName, self.name)):
+ if callFunctionWithTagData:
+ match = self.name(markupName, markupAttrs)
+ else:
+ match = True
+ markupAttrMap = None
+ for attr, matchAgainst in self.attrs.items():
+ if not markupAttrMap:
+ if hasattr(markupAttrs, 'get'):
+ markupAttrMap = markupAttrs
+ else:
+ markupAttrMap = {}
+ for k,v in markupAttrs:
+ markupAttrMap[k] = v
+ attrValue = markupAttrMap.get(attr)
+ if not self._matches(attrValue, matchAgainst):
+ match = False
+ break
+ if match:
+ if markup:
+ found = markup
+ else:
+ found = markupName
+ return found
+
+ def search(self, markup):
+ #print 'looking for %s in %s' % (self, markup)
+ found = None
+ # If given a list of items, scan it for a text element that
+ # matches.
+ if isList(markup) and not isinstance(markup, Tag):
+ for element in markup:
+ if isinstance(element, NavigableString) \
+ and self.search(element):
+ found = element
+ break
+ # If it's a Tag, make sure its name or attributes match.
+ # Don't bother with Tags if we're searching for text.
+ elif isinstance(markup, Tag):
+ if not self.text:
+ found = self.searchTag(markup)
+ # If it's text, make sure the text matches.
+ elif isinstance(markup, NavigableString) or \
+ isString(markup):
+ if self._matches(markup, self.text):
+ found = markup
+ else:
+ raise Exception, "I don't know how to match against a %s" \
+ % markup.__class__
+ return found
+
+ def _matches(self, markup, matchAgainst):
+ #print "Matching %s against %s" % (markup, matchAgainst)
+ result = False
+ if matchAgainst == True and type(matchAgainst) == types.BooleanType:
+ result = markup != None
+ elif callable(matchAgainst):
+ result = matchAgainst(markup)
+ else:
+ #Custom match methods take the tag as an argument, but all
+ #other ways of matching match the tag name as a string.
+ if isinstance(markup, Tag):
+ markup = markup.name
+ if markup is not None and not isString(markup):
+ markup = unicode(markup)
+ #Now we know that chunk is either a string, or None.
+ if hasattr(matchAgainst, 'match'):
+ # It's a regexp object.
+ result = markup and matchAgainst.search(markup)
+ elif (isList(matchAgainst)
+ and (markup is not None or not isString(matchAgainst))):
+ result = markup in matchAgainst
+ elif hasattr(matchAgainst, 'items'):
+ result = markup.has_key(matchAgainst)
+ elif matchAgainst and isString(markup):
+ if isinstance(markup, unicode):
+ matchAgainst = unicode(matchAgainst)
+ else:
+ matchAgainst = str(matchAgainst)
+
+ if not result:
+ result = matchAgainst == markup
+ return result
+
+class ResultSet(list):
+ """A ResultSet is just a list that keeps track of the SoupStrainer
+ that created it."""
+ def __init__(self, source):
+ list.__init__([])
+ self.source = source