Split OAuth2 logic from input/output processing about oauth2-php HOT 4 OPEN

I think this is a good suggestion too. BTW, any code snippet as example of your 
idea?

I agree. Instead of directly accesing the the superglobals 
$_SERVER/$_POST/$_GET i would suggesto introduce kind of a "request" object, 
that can be injected to the actualy oauth object. 

This would be useful for unit testing as well since one could mock this request 
object.

Same should be done for the backend tocken handling. Instead of using 
inheritence i suggest to introduce a "backend object" implementing an interface 
and inject this as well.
So the the actual oauth lib would do nothing but talking its request and the 
backend object without knowing their inner logic aka data source.

[deleted comment]

Some visuals just to get an idea:
http://tinyurl.com/6aeguzd

the request should probably offer an opportunity to esplictly get "crytable" 
parameters (like $_POST) for web. (needed for grant access token and grant type 
password)