Add a Policy template writer that generates Android resources which can be exposed through Android'…

grit/format/policy_templates/writers/android_policy_writer.py

+#!/usr/bin/env python
+# Copyright (c) 2015 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.
+
+
+from grit.format.policy_templates.writers import xml_formatted_writer
+from xml.dom import minidom
+from xml.sax import saxutils as xml_escape
+
+
+def GetWriter(config):
+  '''Factory method for creating AndroidPolicyWriter objects.

[Nico, 2015/03/02 19:02:06]

Style guide says use """ for doc strings (but ' for other strings). Also, no
newline before the closing """ in general.

[knn, 2015/03/02 19:54:35]

Acknowledged. Will have to update other files in this directory for consistency
though.

+  See the constructor of TemplateWriter for description of
+  arguments.
+  '''
+  return AndroidPolicyWriter(['android'], config)
+

[Nico, 2015/03/02 19:02:06]

nit: python style guide says two newlines between toplevel statements

[knn, 2015/03/02 19:54:35]

Done.

+def _EscapeResource(resource):
+  '''Escape the resource for usage in an Android resource XML file.
+  This includes standard XML escaping as well as those specific to Android.
+  '''
+  if type(resource) == int:
+    return str(resource)
+  return xml_escape.escape(resource, {"'": "\\'", '"': '\\"', '\\': '\\\\'})
+
+class AndroidPolicyWriter(xml_formatted_writer.XMLFormattedWriter):
+  '''Outputs localized Android Resource XML files.
+  The policy strings are localized and exposed as string resources for
+  consumption through Android's App restriction Schema.
+  '''
+
+  # DOM root node of the generated ADML document.
+  _doc = None

[Nico, 2015/03/02 19:02:06]

Instance variables are usually set in __init__ in python (e.g. because of
http://stackoverflow.com/questions/867219/python-class-members-initialization
but also other reasons)


Also, it looks like grit names members doc_ not _doc

[knn, 2015/03/02 19:54:35]

Other files in this directory are using this convention as well. Will have to
change all of them.

+  # The resources node contains all resource 'string' and 'string-array'
+  # elements.
+  _resources = None
+
+  def AddStringResource(self, name, string):
+    '''Add a string resource of the given name.
+    '''
+    string_node = self._doc.createElement('string')
+    string_node.setAttribute('name', name)
+    string_node.appendChild(self._doc.createTextNode(_EscapeResource(string)))
+    self._resources.appendChild(string_node)
+
+  def AddStringArrayResource(self, name, string_items):
+    '''Add a string-array resource of the given name and
+    elements from string_items.
+    '''
+    string_array_node = self._doc.createElement('string-array')
+    string_array_node.setAttribute('name', name)
+    self._resources.appendChild(string_array_node)
+    for item in string_items:
+      string_node = self._doc.createElement('item')
+      string_node.appendChild(self._doc.createTextNode(_EscapeResource(item)))
+      string_array_node.appendChild(string_node)
+
+  def PreprocessPolicies(self, policy_list):
+    return self.FlattenGroupsAndSortPolicies(policy_list)
+
+  def CanBeRecommended(self, policy):
+    return False
+
+  def IsDeprecatedPolicySupported(self, policy):
+    return True
+
+  def IsFuturePolicySupported(self, policy):
+    return True
+
+  def WritePolicy(self, policy):
+    name = policy['name']
+    self.AddStringResource(name + 'Title', policy['caption'])
+
+    # Get the first line of the policy description.
+    description = policy['desc'].split('\n', 1)[0]
+    self.AddStringResource(name + 'Desc', description)
+
+    items = policy.get('items')
+    if items is not None:
+      entries = [ item['caption'] for item in items ]
+      values = [ item['value'] for item in items ]
+      self.AddStringArrayResource(name + 'Entries', entries)
+      self.AddStringArrayResource(name + 'Values', values)
+
+  def BeginTemplate(self):
+    comment_text = 'DO NOT MODIFY THIS FILE DIRECTLY!\n' \
+                   'IT IS GENERATED FROM policy_templates.json.'
+    comment_node = self._doc.createComment(comment_text)
+    self._doc.insertBefore(comment_node, self._resources)
+
+  def Init(self):

[Nico, 2015/03/02 19:02:06]

What's wrong with doing this in __init__?

(Looks like other places in grit also have an Init() method, but I don't
understand why.)

[knn, 2015/03/02 19:54:35]

Acknowledged. Will update other files as well.

+    impl = minidom.getDOMImplementation()
+    self._doc = impl.createDocument(None, 'resources', None)
+    self._resources = self._doc.documentElement
+
+  def GetTemplateText(self):
+    return self.ToPrettyXml(self._doc)