Slowly start moving XML parsing function in gcl to glcient.

gclient.py

 #!/usr/bin/python
 #
 # Copyright 2008 Google Inc.  All Rights Reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
 #      http://www.apache.org/licenses/LICENSE-2.0
 #
@@ skipping 240 matching lines @@
       #\"data/really_large_component\": None,
     },
     \"safesync_url\": \"%s\"
   }
 ]
 """)
 
 
 ## Generic utils
 
-
-def getText(nodelist):
-  """
-  Return the concatenated text for the children of a list of DOM nodes.
-  """
-  rc = []
-  for node in nodelist:
-    if node.nodeType == node.TEXT_NODE:
-      rc.append(node.data)
-    else:
-      rc.append(getText(node.childNodes))
-  return ''.join(rc)
-
-
 def ParseXML(output):
   try:
     return xml.dom.minidom.parseString(output)
   except xml.parsers.expat.ExpatError:
     return None
 
 
+def GetNamedNodeText(node, node_name):
+  child_nodes = node.getElementsByTagName(node_name)
+  if not child_nodes:
+    return None
+  assert len(child_nodes) == 1 and child_nodes[0].childNodes.length == 1
+  return child_nodes[0].firstChild.nodeValue
+
+
+def GetNodeNamedAttributeText(node, node_name, attribute_name):
+  child_nodes = node.getElementsByTagName(node_name)
+  if not child_nodes:
+    return None
+  assert len(child_nodes) == 1
+  return child_nodes[0].getAttribute(attribute_name)
+
+
 class Error(Exception):
   """gclient exception class."""
   pass
 
 class PrintableObject(object):
   def __str__(self):
     output = ''
     for i in dir(self):
       if i.startswith('__'):
         continue
@@ skipping 266 matching lines @@
   """Runs 'svn info' on an existing path.
 
   Args:
     relpath: The directory where the working copy resides relative to
       the directory given by in_directory.
     in_directory: The directory where svn is to be run.
 
   Returns:
     An object with fields corresponding to the output of 'svn info'
   """
-  info = CaptureSVN(options, ["info", "--xml", relpath], in_directory)
-  dom = xml.dom.minidom.parseString(info)
-
-  # str() the getText() results because they may be returned as
-  # Unicode, which interferes with the higher layers matching up
-  # things in the deps dictionary.
+  dom = ParseXML(CaptureSVN(options, ["info", "--xml", relpath], in_directory))
   result = PrintableObject()
-  result.root = str(getText(dom.getElementsByTagName('root')))
-  result.url = str(getText(dom.getElementsByTagName('url')))
-  result.uuid = str(getText(dom.getElementsByTagName('uuid')))
-  result.revision = int(dom.getElementsByTagName('entry')[0].getAttribute(
-                            'revision'))
+  if dom:
+    # /info/entry/
+    #   url
+    #   reposityory/(root|uuid)
+    #   wc-info/(schedule|depth)
+    #   commit/(author|date)
+    # str() the results because they may be returned as Unicode, which
+    # interferes with the higher layers matching up things in the deps
+    # dictionary.
+    result = PrintableObject()
+    result.root = str(GetNamedNodeText(dom, 'root'))
+    result.url = str(GetNamedNodeText(dom, 'url'))
+    result.uuid = str(GetNamedNodeText(dom, 'uuid'))
+    result.revision = int(GetNodeNamedAttributeText(dom, 'entry', 'revision'))
   return result
 
 
 def CaptureSVNHeadRevision(options, url):
   """Get the head revision of a SVN repository.
 
   Returns:
     Int head revision
   """
   info = CaptureSVN(options, ["info", "--xml", url], os.getcwd())
@@ skipping 1106 matching lines @@
 
 if "__main__" == __name__:
   try:
     result = Main(sys.argv)
   except Error, e:
     print "Error: %s" % str(e)
     result = 1
   sys.exit(result)
 
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