mirror of
https://github.com/moparisthebest/SickRage
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77 lines
3.3 KiB
Python
77 lines
3.3 KiB
Python
"""A collection of modules for building different kinds of tree from
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HTML documents.
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To create a treebuilder for a new type of tree, you need to do
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implement several things:
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1) A set of classes for various types of elements: Document, Doctype,
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Comment, Element. These must implement the interface of
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_base.treebuilders.Node (although comment nodes have a different
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signature for their constructor, see treebuilders.etree.Comment)
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Textual content may also be implemented as another node type, or not, as
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your tree implementation requires.
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2) A treebuilder object (called TreeBuilder by convention) that
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inherits from treebuilders._base.TreeBuilder. This has 4 required attributes:
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documentClass - the class to use for the bottommost node of a document
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elementClass - the class to use for HTML Elements
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commentClass - the class to use for comments
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doctypeClass - the class to use for doctypes
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It also has one required method:
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getDocument - Returns the root node of the complete document tree
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3) If you wish to run the unit tests, you must also create a
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testSerializer method on your treebuilder which accepts a node and
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returns a string containing Node and its children serialized according
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to the format used in the unittests
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"""
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from __future__ import absolute_import, division, unicode_literals
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from ..utils import default_etree
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treeBuilderCache = {}
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def getTreeBuilder(treeType, implementation=None, **kwargs):
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"""Get a TreeBuilder class for various types of tree with built-in support
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treeType - the name of the tree type required (case-insensitive). Supported
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values are:
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"dom" - A generic builder for DOM implementations, defaulting to
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a xml.dom.minidom based implementation.
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"etree" - A generic builder for tree implementations exposing an
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ElementTree-like interface, defaulting to
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xml.etree.cElementTree if available and
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xml.etree.ElementTree if not.
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"lxml" - A etree-based builder for lxml.etree, handling
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limitations of lxml's implementation.
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implementation - (Currently applies to the "etree" and "dom" tree types). A
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module implementing the tree type e.g.
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xml.etree.ElementTree or xml.etree.cElementTree."""
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treeType = treeType.lower()
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if treeType not in treeBuilderCache:
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if treeType == "dom":
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from . import dom
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# Come up with a sane default (pref. from the stdlib)
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if implementation is None:
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from xml.dom import minidom
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implementation = minidom
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# NEVER cache here, caching is done in the dom submodule
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return dom.getDomModule(implementation, **kwargs).TreeBuilder
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elif treeType == "lxml":
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from . import etree_lxml
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treeBuilderCache[treeType] = etree_lxml.TreeBuilder
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elif treeType == "etree":
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from . import etree
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if implementation is None:
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implementation = default_etree
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# NEVER cache here, caching is done in the etree submodule
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return etree.getETreeModule(implementation, **kwargs).TreeBuilder
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else:
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raise ValueError("""Unrecognised treebuilder "%s" """ % treeType)
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return treeBuilderCache.get(treeType)
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