Added support for token caching and refresh

examples/user_playlists.py

@@ -17,29 +17,37 @@ else:
 
 # Create these via developer.spotify.com/my-applications
 
-client_id = os.getenv('CLIENT_ID')
-client_secret = os.getenv('CLIENT_SECRET')
-redirect_uri = os.getenv('REDIRECT_URI')
+client_id = os.getenv('CLIENT_ID', 'YOUR_CLIENT_ID')
+client_secret = os.getenv('CLIENT_SECRET', 'YOUR_CLIENT_SECRET')
+redirect_uri = os.getenv('REDIRECT_URI', 'YOUR_REDIRECT_URI')
 
 print 'client_id', client_id
 print 'client_secret', client_secret
 print 'redirect_uri', redirect_uri
 
-# Oauth flow
-sp_oauth = oauth2.SpotifyOAuth(client_id, client_secret, redirect_uri)
+sp_oauth = oauth2.SpotifyOAuth(client_id, client_secret, redirect_uri, cache_path=username)
+
+
+# try to get a valid token for this user, from the cache,
+# if not in the cache, the create a new (this will send
+# the user to a web page where they can authorize this app)
+
+token_info = sp_oauth.get_cached_token()
+
+if not token_info:
     auth_url = sp_oauth.get_authorize_url()
     try:
         subprocess.call(["open", auth_url])
         print "Opening %s in your browser" % auth_url
     except:
         print "Please navigate here: %s" % auth_url
-
     response = raw_input("The URL you were redirected to: ")
     code = sp_oauth.parse_response_code(response)
-access_token = sp_oauth.get_access_token(code)
+    token_info = sp_oauth.get_access_token(code)
 
 # Auth'ed API request
+sp = spotipy.Spotify(auth=token_info['access_token'])
 
-sp = spotipy.Spotify(auth=access_token)
 playlists = sp.user_playlists(username)
-pprint.pprint(playlists)
+for playlist in playlists['items']:
+    print playlist['name']

spotipy/oauth2.py

@@ -1,8 +1,9 @@
 import base64
 import urllib
 import requests
-
-print ('oauth2 is here')
+import os
+import simplejson as json
+import time
 
 class SpotifyOauthError(Exception):
     pass
@@ -15,12 +16,38 @@ class SpotifyOAuth(object):
 
     OAUTH_AUTHORIZE_URL = 'https://accounts.spotify.com/authorize'
     OAUTH_TOKEN_URL = 'https://accounts.spotify.com/api/token'
-    def __init__(self, client_id, client_secret, redirect_uri, state=None, scope=None):
+
+    def __init__(self, client_id, client_secret, redirect_uri, state=None, scope=None, cache_path=None):
         self.client_id = client_id
         self.client_secret = client_secret
         self.redirect_uri = redirect_uri
         self.state=state
         self.scope=scope
+        self.cache_path = cache_path
+   
+    def get_cached_token(self):
+        token_info = None
+        if self.cache_path:
+            try:
+                f = open(self.cache_path)
+                token_info_string = f.read()
+                f.close()
+                token_info = json.loads(token_info_string)
+                if self.is_token_expired(token_info):
+                    new_token_info = self.refresh_access_token(token_info['refresh_token'])
+            except IOError:
+                pass
+        return token_info
+
+    def save_token_info(self, token_info):
+        if self.cache_path:
+            f = open(self.cache_path, 'w')
+            print >>f, json.dumps(token_info)
+            f.close()
+
+    def is_token_expired(self, token_info):
+        now = int(time.time())
+        return token_info['expires_at'] < now
         
     def get_authorize_url(self):
         payload = {'client_id': self.client_id,
@@ -54,4 +81,23 @@ class SpotifyOAuth(object):
         response = requests.post(self.OAUTH_TOKEN_URL, data=payload, headers=headers, verify=True)
         if response.status_code is not 200:
             raise SpotifyOauthError(response.reason)
-        return response.json()['access_token']
+        token_info = response.json()
+        token_info['expires_at'] = int(time.time()) + token_info['expires_in']
+        self.save_token_info(token_info)
+        return token_info
+
+    def refresh_access_token(self, refresh_token):
+        payload = { 'refresh_token': refresh_token,
+                   'grant_type': 'refresh_token'}
+
+        auth_header = base64.b64encode(self.client_id + ':' + self.client_secret)
+        headers = {'Authorization': 'Basic %s' % auth_header}
+        response = requests.post(self.OAUTH_TOKEN_URL, data=payload, headers=headers, verify=True)
+        if response.status_code is not 200:
+            raise SpotifyOauthError(response.reason)
+        token_info = response.json()
+        token_info['expires_at'] = int(time.time()) + token_info['expires_in']
+        token_info['refresh_token'] = refresh_token
+        self.save_token_info(token_info)
+        return token_info
+