Making OAuth2Decorator more extensible. Fixes Issue 256.

Making OAuth2Decorator more extensible. Fixes Issue 256.

[dhermes, 2013-04-04 21:46:37]

I had to write 
https://codereview.appspot.com/8358046
to make the tests run, so we should hold off on reviewing this until that review
finishes.

1.) The tests run fine with this change
2.) I left two comments in the code for discussion
3.) Maybe we should consider overriding _fix_up on our properties so that they
can set an attribute on the model class signifying where the credentials
property is, this would make it so StorageByKeyName doesn't need to know the
property name,

NDB Reference:
https://code.google.com/p/appengine-ndb-experiment/source/browse/ndb/model.py...

This has access to the cls that owns the property and the local and datastore
names of the property (they may be the same).

DB Reference:
https://code.google.com/p/googleappengine/source/browse/trunk/python/google/a...

It's called __property_config__ instead of _fix_up but does the same thing and
has the same signature.

[jcgregorio_google, 2013-04-05 14:42:34]

https://codereview.appspot.com/8357047/diff/1/oauth2client/appengine.py
File oauth2client/appengine.py (right):

https://codereview.appspot.com/8357047/diff/1/oauth2client/appengine.py#newco...
oauth2client/appengine.py:612: the average user. A storage class to aid in
storing a Credentials object
Avoid "the average user", just say this isn't typically provided.

[dhermes, 2013-04-05 16:35:30]

Syncing review update-oauth2-decorator at
1c3136350b7cceec351a2fc0ab0ec4cc61010c6b.

[dhermes, 2013-04-05 16:37:51]

Changing docstring per review.

[dhermes, 2013-04-05 16:38:45]

PTAL

Also, what are your thoughts on the 2 TODO's in StorageByKeyName?

https://codereview.appspot.com/8357047/diff/1/oauth2client/appengine.py
File oauth2client/appengine.py (right):

https://codereview.appspot.com/8357047/diff/1/oauth2client/appengine.py#newco...
oauth2client/appengine.py:612: the average user. A storage class to aid in
storing a Credentials object
On 2013/04/05 14:42:34, jcgregorio_google wrote:
> Avoid "the average user", just say this isn't typically provided.

Done.

[jcgregorio_google, 2013-04-05 16:39:54]

LGTM after adding the exception.

https://codereview.appspot.com/8357047/diff/9001/oauth2client/appengine.py
File oauth2client/appengine.py (right):

https://codereview.appspot.com/8357047/diff/9001/oauth2client/appengine.py#ne...
oauth2client/appengine.py:385: # TODO: DISCUSS, Should we throw an exception if
not None
Raise exception if both key_name and user are None.

[dhermes, 2013-04-05 16:56:07]

Raising error if StorageByKeyName gets no key name AND an empty user.

[dhermes, 2013-04-05 16:57:35]

Syncing review update-oauth2-decorator at
961fd9d8e8dde52a942143f08568ac8cec6e7137.

[dhermes, 2013-04-05 16:59:10]

Added in
https://code.google.com/p/google-api-python-client/source/detail?r=07913911fb...