[Android] Warning if Left/Right attributes are used in layout and style xmls.

build/android/gyp/generate_v14_resources.py

 #!/usr/bin/env python
 #
 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Convert Android xml resources to API 14 compatible.
 
 There are two reasons that we cannot just use API attributes,
 so we are generating another set of resources by this script.
 
 1. paddingStart attribute can cause a crash on Galaxy Tab 2.
 2. There is a bug that paddingStart does not override paddingLeft on
    JB-MR1. This is fixed on JB-MR2.
 
 Therefore, this resource generation script can be removed when
 we drop the support for JB-MR1.
 
 Please refer to http://crbug.com/235118 for the details.
 """
 
 import optparse
 import os
 import re
 import sys
 import xml.dom.minidom as minidom
 
 from util import build_utils
 
+# Note that we are assumping 'android:' is an alias of

[newt (away), 2013/05/10 01:15:49]

"assuming"

[Kibeom Kim (inactive), 2013/05/10 02:14:27]

Done.

+# the namespace 'http://schemas.android.com/apk/res/android'.
 
-ATTRIBUTE_NAMESPACE = 'http://schemas.android.com/apk/res/android'
+GRAVITY_ATTRIBUTES = ('android:gravity', 'android:layout_gravity')
 
 # Almost all the attributes that has "Start" or "End" in
 # its name should be mapped.
 ATTRIBUTES_TO_MAP = {'paddingStart' : 'paddingLeft',
                      'drawableStart' : 'drawableLeft',
                      'layout_alignStart' : 'layout_alignLeft',
                      'layout_marginStart' : 'layout_marginLeft',
                      'layout_alignParentStart' : 'layout_alignParentLeft',
                      'layout_toStartOf' : 'layout_toLeftOf',
                      'paddingEnd' : 'paddingRight',
                      'drawableEnd' : 'drawableRight',
                      'layout_alignEnd' : 'layout_alignRight',
                      'layout_marginEnd' : 'layout_marginRight',
                      'layout_alignParentEnd' : 'layout_alignParentRight',
                      'layout_toEndOf' : 'layout_toRightOf'}
 
-ATTRIBUTES_TO_MAP_NS = {}
+ATTRIBUTES_TO_MAP = dict(['android:' + k, 'android:' + v] for k, v
+                         in ATTRIBUTES_TO_MAP.iteritems())
 
-for k, v in ATTRIBUTES_TO_MAP.items():
-  ATTRIBUTES_TO_MAP_NS[(ATTRIBUTE_NAMESPACE, k)] = (ATTRIBUTE_NAMESPACE, v)
-
-ATTRIBUTES_TO_MAP_NS_VALUES = set(ATTRIBUTES_TO_MAP_NS.values())
+ATTRIBUTES_TO_MAP_REVERSED = dict([v,k] for k, v
+                                  in ATTRIBUTES_TO_MAP.iteritems())
 
 
 def IterateXmlElements(node):
   """minidom helper function that iterates all the element nodes.
   Iteration order is pre-order depth-first."""
   if node.nodeType == node.ELEMENT_NODE:
     yield node
   for child_node in node.childNodes:
     for child_node_element in IterateXmlElements(child_node):
       yield child_node_element
 
 
-def GenerateV14StyleResource(dom, output_file):
+def WarnDeprecatedAttribute(name, value, file):

[newt (away), 2013/05/10 01:16:43]

also: it's better to use filename instead of file, which has a built-in meaning
in python

[Kibeom Kim (inactive), 2013/05/10 02:14:27]

Done.

+  if name in ATTRIBUTES_TO_MAP_REVERSED:
+    print >> sys.stderr, ('warning: ' +file + ' should use ' +

[newt (away), 2013/05/10 01:15:49]

nit: space before "file"

[Kibeom Kim (inactive), 2013/05/10 02:14:27]

Done.

+                          ATTRIBUTES_TO_MAP_REVERSED[name] +
+                          ' instead of ' + name)
+  elif name in GRAVITY_ATTRIBUTES and ('left' in value or 'right' in value):

[newt (away), 2013/05/10 01:15:49]

elif name in GRAVITY_ATTRIBUTES and value in ('left', 'right'):

[Kibeom Kim (inactive), 2013/05/10 02:14:27]

But what if value == 'left|top' ?

[newt (away), 2013/05/10 06:13:50]

ah, good point. looks good as is.

+    print >> sys.stderr, ('warning: ' + file +
+                          ' should use start/end instead of left/right for ' +
+                          name)
+
+
+def GenerateV14StyleResource(input_file, output_file):
   """Convert style resource to API 14 compatible style resource.
 
   It's mostly a simple replacement, s/Start/Left s/End/Right,
   on the attribute names specified by <item> element.
   """
+  dom = minidom.parse(input_file)
+
   for style_element in dom.getElementsByTagName('style'):
     for item_element in style_element.getElementsByTagName('item'):
-      namespace, name = item_element.attributes['name'].value.split(':')
-      # Note: namespace == 'android' is not precise because
-      # we are looking for 'http://schemas.android.com/apk/res/android' and
-      # 'android' can be aliased to another name in layout xml files where
-      # this style is used. e.g. xmlns:android="http://crbug.com/".
-      if namespace == 'android' and name in ATTRIBUTES_TO_MAP:
-        mapped_name = ATTRIBUTES_TO_MAP[name]
-        item_element.attributes['name'] = namespace + ':' + mapped_name
+      name = item_element.attributes['name']

[newt (away), 2013/05/10 01:15:49]

add ".value" to the end of the line?

[Kibeom Kim (inactive), 2013/05/10 02:14:27]

Done. Thanks for catching this!

+      value = item_element.childNodes[0].nodeValue
+      if name in ATTRIBUTES_TO_MAP:
+        item_element.attributes['name'] = ATTRIBUTES_TO_MAP[name]
+      else:
+        WarnDeprecatedAttribute(name, value, 'xxx')

[Kibeom Kim (inactive), 2013/05/10 00:31:39]

oops, 'xxx' to file

[newt (away), 2013/05/10 01:15:49]

'xxx' -> input_file

[Kibeom Kim (inactive), 2013/05/10 02:14:27]

Done.

[Kibeom Kim (inactive), 2013/05/10 02:14:27]

Done.

 
   build_utils.MakeDirectory(os.path.dirname(output_file))
   with open(output_file, 'w') as f:
     dom.writexml(f, '', '  ', '\n', encoding='utf-8')
 
 
 def GenerateV14LayoutResource(input_file, output_file):
   """Convert layout resource to API 14 compatible layout resource.
 
   It's mostly a simple replacement, s/Start/Left s/End/Right,
   on the attribute names.
   """
   dom = minidom.parse(input_file)

[newt (away), 2013/05/10 01:15:49]

you could use ElementTree and xpath here:

    tree = ElementTree.parse(input_file)
    for item in tree.findall('resources/style/items'):
        ...

[Kibeom Kim (inactive), 2013/05/10 02:14:27]

Actually, I used cElementTree before because it's the fastest built-in xml
parser http://effbot.org/zone/celementtree.htm , but then it uses
xmlns:ns0="http://schemas.android.com/apk/res/android" by default and to set
'android' instead of 'ns0' I had to call
xml.etree.ElementTree.register_namespace(...) which is a v2.7 function. So I
switched to minidom.

[newt (away), 2013/05/10 06:13:50]

ah. looks like there's a solution in python 2.6: look for
"ET._namespace_map[uri] = prefix" in
http://effbot.org/zone/element-namespaces.htm . But I think it's fine to leave
this as it is.

 
+  # Iterate all the elements' attributes to find attributes to convert.
   for element in IterateXmlElements(dom):
-    all_names = element.attributes.keysNS()
-
-    # Iterate all the attributes to find attributes to convert.
-    # Note that name variable is actually a tuple that has namespace and name.
-    # For example,
-    # name == ('http://schemas.android.com/apk/res/android', 'paddingStart')
-    for name, value in list(element.attributes.itemsNS()):
+    for name, value in list(element.attributes.items()):
+      # Convert any other API 17 Start/End attributes to Left/Right attributes.
+      # For example, from paddingStart="10dp" to paddingLeft="10dp"
       # Note: gravity attributes are not necessary to convert because
       # start/end values are backward-compatible. Explained at
       # https://plus.sandbox.google.com/+RomanNurik/posts/huuJd8iVVXY?e=Showroom
-
-      # Convert any other API 17 Start/End attributes to Left/Right attributes.
-      # For example, from paddingStart="10dp" to paddingLeft="10dp"
-      if name in ATTRIBUTES_TO_MAP_NS:
-        mapped_name = ATTRIBUTES_TO_MAP_NS[name]
-
-        # Add the new mapped attribute and remove the original attribute.
-        # For example, add paddingLeft and remove paddingStart.
-        # Note that instead of element.setAttribute(...), this is more correct.
-        # element.setAttributeNS(mapped_name[0], mapped_name[1], value)
-        # However, there is a minidom bug that doesn't print namespace set by
-        # setAttributeNS. Hence this workaround.
-        # This is a similar bug discussion about minidom namespace normalizing.
-        # http://stackoverflow.com/questions/863774/how-to-generate-xml-documents-with-namespaces-in-python
-        element.setAttribute('android:' + mapped_name[1], value)
+      if name in ATTRIBUTES_TO_MAP:
+        element.setAttribute(ATTRIBUTES_TO_MAP[name], value)
         del element.attributes[name]
-      elif name in ATTRIBUTES_TO_MAP_NS_VALUES:
-        # TODO(kkimlabs): Enable  warning once layouts have been converted
-        # print >> sys.stderror, 'Warning: layout should use xxx instead of yyy'
-        pass
+      else:
+        WarnDeprecatedAttribute(name, value, input_file)
 
   build_utils.MakeDirectory(os.path.dirname(output_file))
   with open(output_file, 'w') as f:
     dom.writexml(f, '', '  ', '\n', encoding='utf-8')
 
 
 def GenerateV14XmlResourcesInDir(input_dir, output_dir, only_styles=False):
   """Convert resources to API 14 compatible XML resources in the directory."""
   for input_file in build_utils.FindInDirectory(input_dir, '*.xml'):
     output_file = os.path.join(output_dir,
                                os.path.relpath(input_file, input_dir))
     if only_styles:
       dom = minidom.parse(input_file)

[newt (away), 2013/05/10 01:15:49]

instead of parsing input_file twice, I'd remove these three lines. Then, in
GenerateV14StyleResource(), check if input_file has any style elements. if it
doesn't, no need generate the output file.

[Kibeom Kim (inactive), 2013/05/10 02:14:27]

Done.

       if not dom.getElementsByTagName('style'):
         continue
-      GenerateV14StyleResource(dom, output_file)
+      GenerateV14StyleResource(input_file, output_file)
     else:
       GenerateV14LayoutResource(input_file, output_file)
 
 
 def ParseArgs():
   """Parses command line options.
 
   Returns:
     An options object as from optparse.OptionsParser.parse_args()
   """
@@ skipping 46 matching lines @@
       GenerateV14XmlResourcesInDir(input_dir, output_dir)
     elif resource_type in ('values'):
       GenerateV14XmlResourcesInDir(input_dir, output_dir, only_styles=True)
 
   if options.stamp:
     build_utils.Touch(options.stamp)
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv))