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 XmlParseFileSection (FileName, Tag):
  77   """Parse a section of an XML file into a DOM(Document Object Model) and return the DOM."""
  78   try:
  79     f = open(FileName, 'r')
  80   except:
  81     return xml.dom.minidom.parseString('<empty/>')
  82   Start = '<' + Tag
  83   End = '</' + Tag + '>'
  84   File = ''
  85   while File.find(Start) < 0 or File.find(End) < 0:
  86     Section = f.read(0x1000)
  87     if Section == '':
  88       break
  89     File += Section
  90   f.close()
  91   if File.find(Start) < 0 or File.find(End) < 0:
  92     return xml.dom.minidom.parseString('<empty/>')
  93   File = File[File.find(Start):File.find(End)+len(End)]
  94   try:
  95     return xml.dom.minidom.parseString(File)
  96   except:
  97     return xml.dom.minidom.parseString('<empty/>')
  98
  99 def XmlParseStringSection (XmlString, Tag):
 100   """Parse a section of an XML string into a DOM(Document Object Model) and return the DOM."""
 101   Start = '<' + Tag
 102   End = '</' + Tag + '>'
 103   File = XmlString
 104   if File.find(Start) < 0 or File.find(End) < 0:
 105     return xml.dom.minidom.parseString('<empty/>')
 106   File = File[File.find(Start):File.find(End)+len(End)]
 107   try:
 108     return xml.dom.minidom.parseString(File)
 109   except:
 110     return xml.dom.minidom.parseString('<empty/>')
 111
 112 def XmlSaveFile (Dom, FileName, Encoding='UTF-8'):
 113   """Save a DOM(Document Object Model) into an XML file."""
 114   try:
 115     f = open(FileName, 'w')
 116     f.write(Dom.toxml(Encoding).replace('&quot;','"').replace('&gt;','>'))
 117     f.close()
 118     return True
 119   except:
 120     return False
 121
 122 def XmlRemoveElement(Node):
 123   """Remove an element node from DOM(Document Object Model) tree."""
 124   ParentNode = Node.parentNode
 125   if ParentNode == None:
 126     return False
 127   PreviousSibling = Node.previousSibling
 128   while PreviousSibling != None and PreviousSibling.nodeType == PreviousSibling.TEXT_NODE and PreviousSibling.data.strip() == '':
 129     Temp = PreviousSibling
 130     PreviousSibling = PreviousSibling.previousSibling
 131     ParentNode.removeChild(Temp)
 132   ParentNode.removeChild(Node)
 133   return True
 134
 135 def XmlAppendChildElement(ParentNode, TagName, ElementText='', AttributeDictionary = {}):
 136   """Add a child element to a DOM(Document Object Model) tree with optional Attributes."""
 137   TagName = TagName.strip()
 138   if TagName == '':
 139     return False
 140   Depth = 0
 141   Dom = ParentNode
 142   while Dom != None and Dom.nodeType != Dom.DOCUMENT_NODE:
 143     Dom = Dom.parentNode
 144     Depth += 1
 145   if Dom == None:
 146     return False
 147   ParentNode.appendChild(Dom.createTextNode('\n%*s' % (Depth * 2, '')))
 148   ElementNode = Dom.createElement(TagName)
 149   if ElementText != '':
 150     ElementNode.appendChild(Dom.createTextNode(ElementText))
 151   for Item in AttributeDictionary:
 152     ElementNode.setAttribute(Item, AttributeDictionary[Item])
 153   ParentNode.appendChild(ElementNode)
 154   return True
 155
 156
 157 # This acts like the main() function for the script, unless it is 'import'ed into another
 158 # script.
 159 if __name__ == '__main__':
 160
 161   # Nothing to do here. Could do some unit tests.
 162   pass