Dynamically generate a heading for Extension Docs API pages

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

+# Copyright (c) 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.
+
+import json
+import logging
+import os
+
+class ChromeVersionUtility(object):

[not at google - send to devlin, 2013/05/13 21:26:41]

This is so similar to BranchUtility, and BranchUtility even has knowledge of
versions. I'm not really sure where one stops and the other starts. We should
think about combining them into a single file like ChromeHistoryUtility or
something, but, that can wait until later. A follow up CL. Let's do the minimum
amount of cleanup necessary to get this patch in.

+  '''Generates and stores API data sources corresponding to the latest branch
+  number for a given version of Chrome.
+
+  Accesses data found on omahaproxy in order to link branch numbers to version
+  numbers.
+  '''
+
+  def __init__(self, base_path, fetcher, object_store_creator):
+    self._base_path = base_path
+    self._fetcher = fetcher
+    self._object_store = object_store_creator.Create(ChromeVersionUtility,
+                                                     channel=None)
+
+  def GetBranchNumberForVersion(self, version_number):
+    '''Returns the most recent branch number for a given chrome version number
+    using data stored on omahaproxy (see url_constants)
+    '''
+    if version_number == 'trunk':
+      return 'trunk'
+
+    branch = self._object_store.Get(version_number).Get()
+    if branch is not None:
+      return branch
+    try:
+      version_json = json.loads(self._fetcher.Fetch(self._base_path).content)
+    except Exception as e:
+      # If omahaproxy is having problems, report it.
+      #version_json = self._GetFakeData()
+      logging.error('Could not fetch data at Omaha Proxy: %s' % (e))
+      return None

[not at google - send to devlin, 2013/05/13 21:26:41]

let's just let this exception fall all the way through.

[epeterson, 2013/05/15 07:38:34]

Done.

+
+    # Here, entry['title'] looks like: 'title - version#.#.branch#.#'
+    for entry in version_json['events']:
+      version_title = entry['title'].split(' - ')[1].split('.')
+      if version_title[0] == version_number:
+        self._object_store.Set(version_number, version_title[2])
+        return version_title[2]
+    return None

[not at google - send to devlin, 2013/05/13 21:26:41]

throw a ValueError or something

[epeterson, 2013/05/15 07:38:34]

Done.

+
+  def GetLatestVersionNumber(self):

[not at google - send to devlin, 2013/05/13 21:26:41]

need to object-storify this or it won't work offline

+    try:
+      version_json = json.loads(self._fetcher.Fetch(self._base_path).content)

[not at google - send to devlin, 2013/05/13 21:26:41]

might want to lazily populate the version json beacuse you're reading it
multiple times (here and above). only need in-memory because the real caching
happens within the object store, and only the actual stuff we need to cache in
object stores is the results of functions.

+    except Exception as e:
+      #version_json = self._GetFakeData()
+      logging.error('Could not fetch latest version at Omaha Proxy: %s' % (e))
+      return None

[not at google - send to devlin, 2013/05/13 21:26:41]

ditto fall through

[epeterson, 2013/05/15 07:38:34]

Done.

+
+    latest_version = 0
+    for entry in version_json['events']:
+      version_title = entry['title'].split(' - ')[1].split('.')
+      version = int(version_title[0])
+      if version > latest_version:
+        latest_version = version
+    return latest_version
+
+  def _GetFakeData(self):
+    with open(os.path.join('test_data',
+                           'chrome_version_utility',
+                           'omaha_dev_win_history.json')) as f:
+      return json.load(f)

[not at google - send to devlin, 2013/05/13 21:26:41]

delete _GetFakeData and the places where it's commented out

[epeterson, 2013/05/15 07:38:34]

Done.