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 Dom.nodeType==Dom.DOCUMENT_NODE:
  20     return XmlList(Dom.documentElement, String)
  21   if String[0] == "/":
  22     return XmlList(Dom, String[1:])
  23   if String == "" :
  24     return []
  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 XmlElement (Dom, String):
  37   """Return a single element that matches the String which is XPath style syntax."""
  38   try:
  39     return XmlList (Dom, String)[0].firstChild.data.strip()
  40   except:
  41     return ''
  42
  43 def XmlElementData (Dom):
  44   """Get the text for this element."""
  45   return Dom.firstChild.data.strip()
  46
  47 def XmlAttribute (Dom, AttName):
  48   """Return a single attribute named AttName."""
  49   try:
  50     return Dom.getAttribute(AttName)
  51   except:
  52     return ''
  53
  54 def XmlTopTag(Dom):
  55   """Return the name of the Root or top tag in the XML tree."""
  56   return Dom.firstChild.nodeName
  57
  58 def XmlParseFile (FileName):
  59   """Parse an XML file into a DOM and return the DOM."""
  60   try:
  61     f = open(FileName, 'r')
  62     Dom = xml.dom.minidom.parse(f)
  63     f.close()
  64     return Dom
  65   except:
  66     return xml.dom.minidom.parseString('<empty/>')
  67
  68 def XmlParseFileSection (FileName, Tag):
  69   """Parse a section of an XML file into a DOM(Document Object Model) and return the DOM."""
  70   try:
  71     f = open(FileName, 'r')
  72   except:
  73     return xml.dom.minidom.parseString('<empty/>')
  74   Start = '<' + Tag
  75   End = '</' + Tag + '>'
  76   File = ''
  77   while File.find(Start) < 0 or File.find(End) < 0:
  78     Section = f.read(0x1000)
  79     if Section == '':
  80       break
  81     File += Section
  82   f.close()
  83   if File.find(Start) < 0 or File.find(End) < 0:
  84     return xml.dom.minidom.parseString('<empty/>')
  85   File = File[File.find(Start):File.find(End)+len(End)]
  86   try:
  87     return xml.dom.minidom.parseString(File)
  88   except:
  89     return xml.dom.minidom.parseString('<empty/>')
  90
  91 def XmlSaveFile (Dom, FileName, Encoding='UTF-8'):
  92   """Save a DOM(Document Object Model) into an XML file."""
  93   try:
  94     f = open(FileName, 'w')
  95     f.write(Dom.toxml(Encoding).replace('&quot;','"').replace('&gt;','>'))
  96     f.close()
  97     return True
  98   except:
  99     return False
 100
 101 def XmlRemoveElement(Node):
 102   """Remove an element node from DOM(Document Object Model) tree."""
 103   ParentNode = Node.parentNode
 104   if ParentNode == None:
 105     return False
 106   PreviousSibling = Node.previousSibling
 107   while PreviousSibling != None and PreviousSibling.nodeType == PreviousSibling.TEXT_NODE and PreviousSibling.data.strip() == '':
 108     Temp = PreviousSibling
 109     PreviousSibling = PreviousSibling.previousSibling
 110     ParentNode.removeChild(Temp)
 111   ParentNode.removeChild(Node)
 112   return True
 113
 114 def XmlAppendChildElement(ParentNode, TagName, ElementText='', AttributeDictionary = {}):
 115   """Add a child element to a DOM(Document Object Model) tree with optional Attributes."""
 116   TagName = TagName.strip()
 117   if TagName == '':
 118     return False
 119   Depth = 0
 120   Dom = ParentNode
 121   while Dom != None and Dom.nodeType != Dom.DOCUMENT_NODE:
 122     Dom = Dom.parentNode
 123     Depth += 1
 124   if Dom == None:
 125     return False
 126   ParentNode.appendChild(Dom.createTextNode('\n%*s' % (Depth * 2, '')))
 127   ElementNode = Dom.createElement(TagName)
 128   if ElementText != '':
 129     ElementNode.appendChild(Dom.createTextNode(ElementText))
 130   for Item in AttributeDictionary:
 131     ElementNode.setAttribute(Item, AttributeDictionary[Item])
 132   ParentNode.appendChild(ElementNode)
 133   return True
 134
 135
 136 # This acts like the main() function for the script, unless it is 'import'ed into another
 137 # script.
 138 if __name__ == '__main__':
 139
 140   # Nothing to do here. Could do some unit tests.
 141   pass