Tools/Python/XmlRoutines.py

   1 #!/usr/bin/env python
   2
   3 # Copyright (c) 2007, Intel Corporation
   4 # All rights reserved. This program and the accompanying materials
   5 # are licensed and made available under the terms and conditions of the BSD License
   6 # which accompanies this distribution.  The full text of the license may be found at
   7 # http://opensource.org/licenses/bsd-license.php
   8 #
   9 # THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 # WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11
  12 """This is an XML API that uses a syntax similar to XPath, but it is written in
  13 standard python so that no extra python packages are required to use it."""
  14
  15 import xml.dom.minidom
  16
  17 def XmlList(Dom, String):
  18   """Get a list of XML Elements using XPath style syntax."""
  19   if String == "" :
  20     return []
  21   if Dom.nodeType==Dom.DOCUMENT_NODE:
  22     return XmlList(Dom.documentElement, String)
  23   if String[0] == "/":
  24     return XmlList(Dom, String[1:])
  25   TagList = String.split('/')
  26   nodes = []
  27   if Dom.nodeType == Dom.ELEMENT_NODE and Dom.tagName.strip() == TagList[0]:
  28     if len(TagList) == 1:
  29       nodes = [Dom]
  30     else:
  31       restOfPath = "/".join(TagList[1:])
  32       for child in Dom.childNodes:
  33         nodes = nodes + XmlList(child, restOfPath)
  34   return nodes
  35
  36 def XmlNode (Dom, String):
  37   """Return a single node that matches the String which is XPath style syntax."""
  38   try:
  39     return XmlList (Dom, String)[0]
  40   except:
  41     return None
  42
  43
  44 def XmlElement (Dom, String):
  45   """Return a single element that matches the String which is XPath style syntax."""
  46   try:
  47     return XmlList (Dom, String)[0].firstChild.data.strip()
  48   except:
  49     return ''
  50
  51 def XmlElementData (Dom):
  52   """Get the text for this element."""
  53   return Dom.firstChild.data.strip()
  54
  55 def XmlAttribute (Dom, AttName):
  56   """Return a single attribute named AttName."""
  57   try:
  58     return Dom.getAttribute(AttName)
  59   except:
  60     return ''
  61
  62 def XmlTopTag(Dom):
  63   """Return the name of the Root or top tag in the XML tree."""
  64   return Dom.firstChild.nodeName
  65
  66 def XmlParseFile (FileName):
  67   """Parse an XML file into a DOM and return the DOM."""
  68   try:
  69     f = open(FileName, 'r')
  70     Dom = xml.dom.minidom.parse(f)
  71     f.close()
  72     return Dom
  73   except:
  74     return xml.dom.minidom.parseString('<empty/>')
  75
  76 def XmlParseString (Str):
  77   """Parse an XML string into a DOM and return the DOM."""
  78   try:
  79     return xml.dom.minidom.parseString(Str)
  80   except:
  81     return xml.dom.minidom.parseString('<empty/>')
  82
  83 def XmlParseFileSection (FileName, Tag):
  84   """Parse a section of an XML file into a DOM(Document Object Model) and return the DOM."""
  85   try:
  86     f = open(FileName, 'r')
  87   except:
  88     return xml.dom.minidom.parseString('<empty/>')
  89   Start = '<' + Tag
  90   End = '</' + Tag + '>'
  91   File = ''
  92   while File.find(Start) < 0 or File.find(End) < 0:
  93     Section = f.read(0x1000)
  94     if Section == '':
  95       break
  96     File += Section
  97   f.close()
  98   if File.find(Start) < 0 or File.find(End) < 0:
  99     return xml.dom.minidom.parseString('<empty/>')
 100   File = File[File.find(Start):File.find(End)+len(End)]
 101   try:
 102     return xml.dom.minidom.parseString(File)
 103   except:
 104     return xml.dom.minidom.parseString('<empty/>')
 105
 106 def XmlParseStringSection (XmlString, Tag):
 107   """Parse a section of an XML string into a DOM(Document Object Model) and return the DOM."""
 108   Start = '<' + Tag
 109   End = '</' + Tag + '>'
 110   File = XmlString
 111   if File.find(Start) < 0 or File.find(End) < 0:
 112     return xml.dom.minidom.parseString('<empty/>')
 113   File = File[File.find(Start):File.find(End)+len(End)]
 114   try:
 115     return xml.dom.minidom.parseString(File)
 116   except:
 117     return xml.dom.minidom.parseString('<empty/>')
 118
 119 def XmlSaveFile (Dom, FileName, Encoding='UTF-8'):
 120   """Save a DOM(Document Object Model) into an XML file."""
 121   try:
 122     f = open(FileName, 'w')
 123     f.write(Dom.toxml(Encoding).replace('&quot;','"').replace('&gt;','>'))
 124     f.close()
 125     return True
 126   except:
 127     return False
 128
 129 def XmlRemoveElement(Node):
 130   """Remove an element node from DOM(Document Object Model) tree."""
 131   ParentNode = Node.parentNode
 132   if ParentNode == None:
 133     return False
 134   PreviousSibling = Node.previousSibling
 135   while PreviousSibling != None and PreviousSibling.nodeType == PreviousSibling.TEXT_NODE and PreviousSibling.data.strip() == '':
 136     Temp = PreviousSibling
 137     PreviousSibling = PreviousSibling.previousSibling
 138     ParentNode.removeChild(Temp)
 139   ParentNode.removeChild(Node)
 140   return True
 141
 142 def XmlAppendChildElement(ParentNode, TagName, ElementText='', AttributeDictionary = {}):
 143   """Add a child element to a DOM(Document Object Model) tree with optional Attributes."""
 144   TagName = TagName.strip()
 145   if TagName == '':
 146     return None
 147   Depth = 0
 148   Dom = ParentNode
 149   while Dom != None and Dom.nodeType != Dom.DOCUMENT_NODE:
 150     Dom = Dom.parentNode
 151     Depth += 1
 152   if Dom == None:
 153     return None
 154   ParentNode.appendChild(Dom.createTextNode('\n%*s' % (Depth * 2, '')))
 155   ElementNode = Dom.createElement(TagName)
 156   if ElementText != '':
 157     ElementNode.appendChild(Dom.createTextNode(ElementText))
 158   for Item in AttributeDictionary:
 159     ElementNode.setAttribute(Item, AttributeDictionary[Item])
 160   ParentNode.appendChild(ElementNode)
 161   return ElementNode
 162
 163
 164 # This acts like the main() function for the script, unless it is 'import'ed into another
 165 # script.
 166 if __name__ == '__main__':
 167
 168   # Nothing to do here. Could do some unit tests.
 169   pass