Docserver: Consolidate features caching and access.

chrome/common/extensions/docs/server2/permission_features.py

+# 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.
+
+from itertools import ifilter
+from operator import itemgetter
+
+from features import Features
+import features_utility
+from third_party.json_schema_compiler.json_parse import Parse
+
+def _ListifyPermissions(permissions):

[not at google - send to devlin, 2013/09/23 18:31:30]

this should be in the permission_data_source since it's specifically for
populating the 'permissions' template field. same goes for any other data for
that purpose. The pure-model PermissionFeatures stuff (which filters by
extension type etc) should be in here.

Which brings me to another point - we're mid-refactor in moving the data source
into data_source_registry. I think you might be able to do this for
permissions_data_source now and save a bit of effort. If not - that's cool, we
can do it later.

+  '''Filter out any permissions that do not have a description or with a name
+  that ends with Private then sort permissions features by name into a list.
+  '''
+  def filter_permissions(perm):
+    return 'description' in perm and not perm['name'].endswith('Private')
+
+  return sorted(
+      ifilter(filter_permissions, permissions.values()),
+      key=itemgetter('name'))
+
+def _AddDependencyDescriptions(permissions, api_features, template_data_source):
+  '''Use |api_features| to determine the dependencies APIs have on |permission|.
+  Add a description to the permission based on those dependencies.
+  '''
+  for permission in permissions:
+    # Don't overwrite the description created by expanding a partial template.
+    if 'partial' in permission or not permission['platforms']:
+      continue
+    has_deps = False
+    if name in api_features:
+      for dependency in api_features[name].get('dependencies', ()):
+        if dependency.startswith('permission:'):
+          has_deps = True
+    if has_deps:
+      permission['partial'] = 'permissions/generic_description'
+
+  for permission in permissions:
+    # Turn partial templates into descriptions, ensure anchors are set.
+    if not 'anchor' in permission:
+      permission['anchor'] = permission['name']
+    if 'partial' in permission:
+      permission['description'] = self._template_data_source.get(
+          permission['partial'])
+      del permission['partial']
+
+class PermissionFeatures(Features):
+  '''Subclass of Features to provide permission descriptions derived from API
+  dependencies and filter private or undescribed permissions.
+  '''
+  def __init__(self,
+               compiled_fs_factory,
+               permission_features_path,
+               file_system,
+               permissions_json_path):
+    self._file_system = file_system
+    self._permissions_json_path = permissions_json_path
+    self._template_data_source = None
+    super(PermissionFeatures, self).__init__(compiled_fs_factory,
+                                             permission_features_path)
+
+  def Parse(self, features_json):
+    permissions_json = Parse(
+        self._file_system.ReadSingle(self._permissions_json_path))
+    permission_features = features_utility.MergedWith(
+        features_utility.Parse(features_json), permissions_json)
+    return permission_features
+
+  def CreateCache(self, features):
+    return {
+      'declare_apps': _ListifyPermissions(
+          self.FilterByPlatform(features, 'apps')),
+      'declare_extensions': _ListifyPermissions(
+          self.FilterByPlatform(features, 'extensions'))
+    }

[not at google - send to devlin, 2013/09/23 18:31:30]

so... this overrides CreateCache from Features?

if you move the listification into api_data_source hopefully that's not
necessary, because it's a bit surprising.

+
+  def AddDependencyDescriptions(self, api_features, template_data_source):
+    for platform in ('declare_apps', 'declare_extensions'):
+      _AddDependencyDescriptions(self.get(platform),
+                                 api_features,
+                                 template_data_source)