Tony Jackson 9550c8fd86 Create CacheHandler to abstract caching tokens (#625) ... * Refactor functions into static methods of AuthBase Functions is_token_expired was a loose function that was added to SpotifyClientCredentials, SpotifyPKCE, and SpotifyImplicitGrant classes through a method on each class that passed the call to the loose is_token_expired function. Function _is_scope_subset was duplicated on SpotifyClientCredentials, SpotifyPKCE, and SpotifyImplicitGrant classes. Refactoring is_token_expired and _is_scope_subset to be static methods on SpotifyAuthBase means both are available for all derived classes and require less boilerplate. * Create CacheHandler to abstract caching tokens Previous code only supported caching to and from json files in a given directory. In addition, the get_cached_token method mixed getting and getting the token in the same method. This change creates a CacheHandler class to abstract out the caching implementation and allow the user to cache tokens in any way they see fit. For example, the user could create a MongoCache class to store and retrieve tokens from a Mongo database and specify that cache_handler=MongoCache in creating an auth_manager object. To implement the CacheHandler abstraction, the following changes are implemented: The validation code in each get_cached_token method in SpotifyOAuth, SpotifyPKCE, and SpotifyImplicitGrant is moved into a validate_token method in each class. The CacheHandler class is created with get_cached_token and save_token_to_cache methods. Previous instances of self.get_cached_token() are now replaced with self.validate_token(self.cache_handler.get_cached_token()) to preserve the getting and validation behaviour. cache_handler is added as an argument to SpotifyOAuth, SpotifyPKCE, and SpotifyImplicitGrant. Specifying a cache_handler now overrides any specification of cache_path and/or username. To preserve backwards compatibility in handling cache files, a CacheFileHandler class extending CacheHandler is created. If no cache_handler is specified, the cache_path and username arguments are used to create an instance of CacheFileHandler. It may be worth deprecating the cache_path and username fields in favour of using CacheFileHandler. Tests are also modified and extended to cover the new functionality. A sample MemoryCache CacheHandler is created to test getting and saving to a custom CacheHandler. * Fix cache_handler subclass check for Python 2 * Split assert message to fix line over max length * Split cache handlers into cache_handler.py * flake8 and autopep fixes * Fix init to allow importing CacheHandler When spotipy is installed as a package, CacheHandler is not accessible from a `from spotipy import CacheHandler` statement because the import is not specified in the __init__.py file. This commit adds CacheHandler and CacheFileHandler to the init file so the user can import them. * flake8 fix		2020-12-21 11:31:21 +01:00
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__init__.py	Retries For All Endpoints, fixes #347 (#457)	2020-03-29 17:18:23 +01:00
test_oauth.py	Create CacheHandler to abstract caching tokens (#625)	2020-12-21 11:31:21 +01:00