week06

env/lib/python3.12/site-packages/lxml/ElementInclude.py

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+#
+# ElementTree
+# $Id: ElementInclude.py 1862 2004-06-18 07:31:02Z Fredrik $
+#
+# limited xinclude support for element trees
+#
+# history:
+# 2003-08-15 fl   created
+# 2003-11-14 fl   fixed default loader
+#
+# Copyright (c) 2003-2004 by Fredrik Lundh.  All rights reserved.
+#
+# fredrik@pythonware.com
+# http://www.pythonware.com
+#
+# --------------------------------------------------------------------
+# The ElementTree toolkit is
+#
+# Copyright (c) 1999-2004 by Fredrik Lundh
+#
+# By obtaining, using, and/or copying this software and/or its
+# associated documentation, you agree that you have read, understood,
+# and will comply with the following terms and conditions:
+#
+# Permission to use, copy, modify, and distribute this software and
+# its associated documentation for any purpose and without fee is
+# hereby granted, provided that the above copyright notice appears in
+# all copies, and that both that copyright notice and this permission
+# notice appear in supporting documentation, and that the name of
+# Secret Labs AB or the author not be used in advertising or publicity
+# pertaining to distribution of the software without specific, written
+# prior permission.
+#
+# SECRET LABS AB AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
+# TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANT-
+# ABILITY AND FITNESS.  IN NO EVENT SHALL SECRET LABS AB OR THE AUTHOR
+# BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY
+# DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
+# WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
+# ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+# OF THIS SOFTWARE.
+# --------------------------------------------------------------------
+
+"""
+Limited XInclude support for the ElementTree package.
+
+While lxml.etree has full support for XInclude (see
+`etree.ElementTree.xinclude()`), this module provides a simpler, pure
+Python, ElementTree compatible implementation that supports a simple
+form of custom URL resolvers.
+"""
+
+from lxml import etree
+try:
+    from urlparse import urljoin
+    from urllib2 import urlopen
+except ImportError:
+    # Python 3
+    from urllib.parse import urljoin
+    from urllib.request import urlopen
+
+XINCLUDE = "{http://www.w3.org/2001/XInclude}"
+
+XINCLUDE_INCLUDE = XINCLUDE + "include"
+XINCLUDE_FALLBACK = XINCLUDE + "fallback"
+XINCLUDE_ITER_TAG = XINCLUDE + "*"
+
+# For security reasons, the inclusion depth is limited to this read-only value by default.
+DEFAULT_MAX_INCLUSION_DEPTH = 6
+
+
+##
+# Fatal include error.
+
+class FatalIncludeError(etree.LxmlSyntaxError):
+    pass
+
+
+class LimitedRecursiveIncludeError(FatalIncludeError):
+    pass
+
+
+##
+# ET compatible default loader.
+# This loader reads an included resource from disk.
+#
+# @param href Resource reference.
+# @param parse Parse mode.  Either "xml" or "text".
+# @param encoding Optional text encoding.
+# @return The expanded resource.  If the parse mode is "xml", this
+#    is an ElementTree instance.  If the parse mode is "text", this
+#    is a Unicode string.  If the loader fails, it can return None
+#    or raise an IOError exception.
+# @throws IOError If the loader fails to load the resource.
+
+def default_loader(href, parse, encoding=None):
+    file = open(href, 'rb')
+    if parse == "xml":
+        data = etree.parse(file).getroot()
+    else:
+        data = file.read()
+        if not encoding:
+            encoding = 'utf-8'
+        data = data.decode(encoding)
+    file.close()
+    return data
+
+
+##
+# Default loader used by lxml.etree - handles custom resolvers properly
+# 
+
+def _lxml_default_loader(href, parse, encoding=None, parser=None):
+    if parse == "xml":
+        data = etree.parse(href, parser).getroot()
+    else:
+        if "://" in href:
+            f = urlopen(href)
+        else:
+            f = open(href, 'rb')
+        data = f.read()
+        f.close()
+        if not encoding:
+            encoding = 'utf-8'
+        data = data.decode(encoding)
+    return data
+
+
+##
+# Wrapper for ET compatibility - drops the parser
+
+def _wrap_et_loader(loader):
+    def load(href, parse, encoding=None, parser=None):
+        return loader(href, parse, encoding)
+    return load
+
+
+##
+# Expand XInclude directives.
+#
+# @param elem Root element.
+# @param loader Optional resource loader.  If omitted, it defaults
+#     to {@link default_loader}.  If given, it should be a callable
+#     that implements the same interface as <b>default_loader</b>.
+# @param base_url The base URL of the original file, to resolve
+#     relative include file references.
+# @param max_depth The maximum number of recursive inclusions.
+#     Limited to reduce the risk of malicious content explosion.
+#     Pass None to disable the limitation.
+# @throws LimitedRecursiveIncludeError If the {@link max_depth} was exceeded.
+# @throws FatalIncludeError If the function fails to include a given
+#     resource, or if the tree contains malformed XInclude elements.
+# @throws IOError If the function fails to load a given resource.
+# @returns the node or its replacement if it was an XInclude node
+
+def include(elem, loader=None, base_url=None,
+            max_depth=DEFAULT_MAX_INCLUSION_DEPTH):
+    if max_depth is None:
+        max_depth = -1
+    elif max_depth < 0:
+        raise ValueError("expected non-negative depth or None for 'max_depth', got %r" % max_depth)
+
+    if base_url is None:
+        if hasattr(elem, 'getroot'):
+            tree = elem
+            elem = elem.getroot()
+        else:
+            tree = elem.getroottree()
+        if hasattr(tree, 'docinfo'):
+            base_url = tree.docinfo.URL
+    elif hasattr(elem, 'getroot'):
+        elem = elem.getroot()
+    _include(elem, loader, base_url, max_depth)
+
+
+def _include(elem, loader=None, base_url=None,
+             max_depth=DEFAULT_MAX_INCLUSION_DEPTH, _parent_hrefs=None):
+    if loader is not None:
+        load_include = _wrap_et_loader(loader)
+    else:
+        load_include = _lxml_default_loader
+
+    if _parent_hrefs is None:
+        _parent_hrefs = set()
+
+    parser = elem.getroottree().parser
+
+    include_elements = list(
+        elem.iter(XINCLUDE_ITER_TAG))
+
+    for e in include_elements:
+        if e.tag == XINCLUDE_INCLUDE:
+            # process xinclude directive
+            href = urljoin(base_url, e.get("href"))
+            parse = e.get("parse", "xml")
+            parent = e.getparent()
+            if parse == "xml":
+                if href in _parent_hrefs:
+                    raise FatalIncludeError(
+                        "recursive include of %r detected" % href
+                        )
+                if max_depth == 0:
+                    raise LimitedRecursiveIncludeError(
+                        "maximum xinclude depth reached when including file %s" % href)
+                node = load_include(href, parse, parser=parser)
+                if node is None:
+                    raise FatalIncludeError(
+                        "cannot load %r as %r" % (href, parse)
+                        )
+                node = _include(node, loader, href, max_depth - 1, {href} | _parent_hrefs)
+                if e.tail:
+                    node.tail = (node.tail or "") + e.tail
+                if parent is None:
+                    return node # replaced the root node!
+                parent.replace(e, node)
+            elif parse == "text":
+                text = load_include(href, parse, encoding=e.get("encoding"))
+                if text is None:
+                    raise FatalIncludeError(
+                        "cannot load %r as %r" % (href, parse)
+                        )
+                predecessor = e.getprevious()
+                if predecessor is not None:
+                    predecessor.tail = (predecessor.tail or "") + text
+                elif parent is None:
+                    return text # replaced the root node!
+                else:
+                    parent.text = (parent.text or "") + text + (e.tail or "")
+                parent.remove(e)
+            else:
+                raise FatalIncludeError(
+                    "unknown parse type in xi:include tag (%r)" % parse
+                )
+        elif e.tag == XINCLUDE_FALLBACK:
+            parent = e.getparent()
+            if parent is not None and parent.tag != XINCLUDE_INCLUDE:
+                raise FatalIncludeError(
+                    "xi:fallback tag must be child of xi:include (%r)" % e.tag
+                    )
+        else:
+            raise FatalIncludeError(
+                "Invalid element found in XInclude namespace (%r)" % e.tag
+                )
+    return elem