Source Code for Module caldavclientlibrary.protocol.utils.xmlhelpers

  1  ## 
  2  # Copyright (c) 2007-2016 Apple Inc. All rights reserved. 
  3  # 
  4  # Licensed under the Apache License, Version 2.0 (the "License"); 
  5  # you may not use this file except in compliance with the License. 
  6  # You may obtain a copy of the License at 
  7  # 
  8  # http://www.apache.org/licenses/LICENSE-2.0 
  9  # 
 10  # Unless required by applicable law or agreed to in writing, software 
 11  # distributed under the License is distributed on an "AS IS" BASIS, 
 12  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
 13  # See the License for the specific language governing permissions and 
 14  # limitations under the License. 
 15  ## 
 16   
 17  from xml.etree.ElementTree import ElementTree, _namespace_map 
 18  from xml.etree.ElementTree import Comment 
 19  from xml.etree.ElementTree import _escape_cdata 
 20  from xml.etree.ElementTree import ProcessingInstruction 
 21  from xml.etree.ElementTree import QName 
 22  from xml.etree.ElementTree import _raise_serialization_error 
 23  from xml.etree.ElementTree import _encode 
 24  from xml.etree.ElementTree import _escape_attrib 
 25  from StringIO import StringIO 
 26  from xml.etree.ElementTree import SubElement 
 27  import string 
 28   
 29 -def SubElementWithData(parent, tag, data=None, attrs={}): 
 30      element = SubElement(parent, tag, attrs) 
 31      if data: 
 32          element.text = data 
 33      return element 
 34   
 35 -def myfixtag(tag, namespaces): 
 36      # given a decorated tag (of the form {uri}tag), return prefixed 
 37      # tag and namespace declaration, if any 
 38      if isinstance(tag, QName): 
 39          tag = tag.text 
 40      namespace_uri, tag = string.split(tag[1:], "}", 1) 
 41      prefix = namespaces.get(namespace_uri) 
 42      if prefix is None: 
 43          prefix = _namespace_map.get(namespace_uri) 
 44          if prefix is None: 
 45              prefix = "ns%d" % len(namespaces) 
 46          namespaces[namespace_uri] = prefix 
 47          if prefix == "xml": 
 48              xmlns = None 
 49          else: 
 50              xmlns = ("xmlns:%s" % prefix, namespace_uri) 
 51      else: 
 52          xmlns = None 
 53      return "%s:%s" % (prefix, tag), xmlns 
 54   
 55 -class BetterElementTree(ElementTree): 
 56       
 57 -    def writeUTF8(self, file): 
 58          assert self._root is not None 
 59          if not hasattr(file, "write"): 
 60              file = open(file, "wb") 
 61          encoding = "utf-8" 
 62          file.write("<?xml version='1.0' encoding='%s'?>" % encoding) 
 63          self._prettywrite(file, self._root, encoding, {}) 
 64          file.write("\r\n") 
 65   
 66 -    def _prettywrite(self, file, node, encoding, namespaces, depth=0): 
 67          # write XML to file 
 68          tag = node.tag 
 69          if tag is Comment: 
 70              file.write("\r\n" + "  " * depth) 
 71              file.write("<!-- %s -->" % _escape_cdata(node.text, encoding)) 
 72          elif tag is ProcessingInstruction: 
 73              file.write("\r\n" + "  " * depth) 
 74              file.write("<?%s?>" % _escape_cdata(node.text, encoding)) 
 75          else: 
 76              items = node.items() 
 77              xmlns_items = [] # new namespaces in this scope 
 78              try: 
 79                  if isinstance(tag, QName) or tag[:1] == "{": 
 80                      tag, xmlns = myfixtag(tag, namespaces) 
 81                      if xmlns: xmlns_items.append(xmlns) 
 82              except TypeError: 
 83                  _raise_serialization_error(tag) 
 84              file.write("\r\n" + "  " * depth) 
 85              file.write("<" + _encode(tag, encoding)) 
 86              if items or xmlns_items: 
 87                  items.sort() # lexical order 
 88                  for k, v in items: 
 89                      try: 
 90                          if isinstance(k, QName) or k[:1] == "{": 
 91                              k, xmlns = myfixtag(k, namespaces) 
 92                              if xmlns: xmlns_items.append(xmlns) 
 93                      except TypeError: 
 94                          _raise_serialization_error(k) 
 95                      try: 
 96                          if isinstance(v, QName): 
 97                              v, xmlns = myfixtag(v, namespaces) 
 98                              if xmlns: xmlns_items.append(xmlns) 
 99                      except TypeError: 
100                          _raise_serialization_error(v) 
101                      file.write(" %s=\"%s\"" % (_encode(k, encoding), 
102                                                 _escape_attrib(v, encoding))) 
103                  for k, v in xmlns_items: 
104                      file.write(" %s=\"%s\"" % (_encode(k, encoding), 
105                                                 _escape_attrib(v, encoding))) 
106              if node.text or len(node): 
107                  file.write(">") 
108                  if node.text: 
109                      file.write(_escape_cdata(node.text, encoding)) 
110                  for n in node: 
111                      self._prettywrite(file, n, encoding, namespaces, depth=depth+1) 
112                  if not node.text or len(node): 
113                      file.write("\r\n" + "  " * depth) 
114                  file.write("</" + _encode(tag, encoding) + ">") 
115              else: 
116                  file.write(" />") 
117              for k, v in xmlns_items: 
118                  del namespaces[v] 
119          if node.tail: 
120              file.write(_escape_cdata(node.tail, encoding)) 
121   
122 -def elementToString(element): 
123      os = StringIO() 
124      xmldoc = BetterElementTree(element) 
125      xmldoc.writeUTF8(os) 
126      return os.getvalue() 
127