1# 2# ElementTree 3# $Id: ElementInclude.py 3375 2008-02-13 08:05:08Z fredrik $ 4# 5# limited xinclude support for element trees 6# 7# history: 8# 2003-08-15 fl created 9# 2003-11-14 fl fixed default loader 10# 11# Copyright (c) 2003-2004 by Fredrik Lundh. All rights reserved. 12# 13# fredrik@pythonware.com 14# http://www.pythonware.com 15# 16# -------------------------------------------------------------------- 17# The ElementTree toolkit is 18# 19# Copyright (c) 1999-2008 by Fredrik Lundh 20# 21# By obtaining, using, and/or copying this software and/or its 22# associated documentation, you agree that you have read, understood, 23# and will comply with the following terms and conditions: 24# 25# Permission to use, copy, modify, and distribute this software and 26# its associated documentation for any purpose and without fee is 27# hereby granted, provided that the above copyright notice appears in 28# all copies, and that both that copyright notice and this permission 29# notice appear in supporting documentation, and that the name of 30# Secret Labs AB or the author not be used in advertising or publicity 31# pertaining to distribution of the software without specific, written 32# prior permission. 33# 34# SECRET LABS AB AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD 35# TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANT- 36# ABILITY AND FITNESS. IN NO EVENT SHALL SECRET LABS AB OR THE AUTHOR 37# BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY 38# DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, 39# WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 40# ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 41# OF THIS SOFTWARE. 42# -------------------------------------------------------------------- 43 44# Licensed to PSF under a Contributor Agreement. 45# See http://www.python.org/psf/license for licensing details. 46 47## 48# Limited XInclude support for the ElementTree package. 49## 50 51import copy 52from . import ElementTree 53 54XINCLUDE = "{http://www.w3.org/2001/XInclude}" 55 56XINCLUDE_INCLUDE = XINCLUDE + "include" 57XINCLUDE_FALLBACK = XINCLUDE + "fallback" 58 59## 60# Fatal include error. 61 62class FatalIncludeError(SyntaxError): 63 pass 64 65## 66# Default loader. This loader reads an included resource from disk. 67# 68# @param href Resource reference. 69# @param parse Parse mode. Either "xml" or "text". 70# @param encoding Optional text encoding. 71# @return The expanded resource. If the parse mode is "xml", this 72# is an ElementTree instance. If the parse mode is "text", this 73# is a Unicode string. If the loader fails, it can return None 74# or raise an IOError exception. 75# @throws IOError If the loader fails to load the resource. 76 77def default_loader(href, parse, encoding=None): 78 with open(href) as file: 79 if parse == "xml": 80 data = ElementTree.parse(file).getroot() 81 else: 82 data = file.read() 83 if encoding: 84 data = data.decode(encoding) 85 return data 86 87## 88# Expand XInclude directives. 89# 90# @param elem Root element. 91# @param loader Optional resource loader. If omitted, it defaults 92# to {@link default_loader}. If given, it should be a callable 93# that implements the same interface as <b>default_loader</b>. 94# @throws FatalIncludeError If the function fails to include a given 95# resource, or if the tree contains malformed XInclude elements. 96# @throws IOError If the function fails to load a given resource. 97 98def include(elem, loader=None): 99 if loader is None: 100 loader = default_loader 101 # look for xinclude elements 102 i = 0 103 while i < len(elem): 104 e = elem[i] 105 if e.tag == XINCLUDE_INCLUDE: 106 # process xinclude directive 107 href = e.get("href") 108 parse = e.get("parse", "xml") 109 if parse == "xml": 110 node = loader(href, parse) 111 if node is None: 112 raise FatalIncludeError( 113 "cannot load %r as %r" % (href, parse) 114 ) 115 node = copy.copy(node) 116 if e.tail: 117 node.tail = (node.tail or "") + e.tail 118 elem[i] = node 119 elif parse == "text": 120 text = loader(href, parse, e.get("encoding")) 121 if text is None: 122 raise FatalIncludeError( 123 "cannot load %r as %r" % (href, parse) 124 ) 125 if i: 126 node = elem[i-1] 127 node.tail = (node.tail or "") + text + (e.tail or "") 128 else: 129 elem.text = (elem.text or "") + text + (e.tail or "") 130 del elem[i] 131 continue 132 else: 133 raise FatalIncludeError( 134 "unknown parse type in xi:include tag (%r)" % parse 135 ) 136 elif e.tag == XINCLUDE_FALLBACK: 137 raise FatalIncludeError( 138 "xi:fallback tag must be child of xi:include (%r)" % e.tag 139 ) 140 else: 141 include(e, loader) 142 i = i + 1 143