google_apis/gaia/oauth2_api_call_flow.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef GOOGLE_APIS_GAIA_OAUTH2_API_CALL_FLOW_H_
   6 #define GOOGLE_APIS_GAIA_OAUTH2_API_CALL_FLOW_H_
   7
   8 #include <string>
   9
  10 #include "base/memory/scoped_ptr.h"
  11 #include "google_apis/gaia/oauth2_access_token_consumer.h"
  12 #include "google_apis/gaia/oauth2_access_token_fetcher.h"
  13 #include "net/url_request/url_fetcher_delegate.h"
  14
  15 class GoogleServiceAuthError;
  16 class OAuth2MintTokenFlowTest;
  17
  18 namespace net {
  19 class URLFetcher;
  20 class URLRequestContextGetter;
  21 }
  22
  23 // Base class for all classes that implement a flow to call OAuth2
  24 // enabled APIs.
  25 //
  26 // Given a refresh token, an access token, and a list of scopes an OAuth2
  27 // enabled API is called in the following way:
  28 // 1. Try the given access token to call the API.
  29 // 2. If that does not work, use the refresh token and scopes to generate
  30 //    a new access token.
  31 // 3. Try the new access token to call the API.
  32 //
  33 // This class abstracts the basic steps and exposes template methods
  34 // for sub-classes to implement for API specific details.
  35 class OAuth2ApiCallFlow
  36     : public net::URLFetcherDelegate,
  37       public OAuth2AccessTokenConsumer {
  38  public:
  39   // Creates an instance that works with the given data.
  40   // Note that |access_token| can be empty. In that case, the flow will skip
  41   // the first step (of trying an existing access token).
  42   OAuth2ApiCallFlow(
  43       net::URLRequestContextGetter* context,
  44       const std::string& refresh_token,
  45       const std::string& access_token,
  46       const std::vector<std::string>& scopes);
  47
  48   virtual ~OAuth2ApiCallFlow();
  49
  50   // Start the flow.
  51   virtual void Start();
  52
  53 #if defined(OS_CHROMEOS)
  54   void SetChromeOAuthClientInfo(const std::string& chrome_client_id,
  55                                 const std::string& chrome_client_secret);
  56 #endif
  57
  58   // OAuth2AccessTokenFetcher implementation.
  59   virtual void OnGetTokenSuccess(const std::string& access_token,
  60                                  const base::Time& expiration_time) OVERRIDE;
  61   virtual void OnGetTokenFailure(const GoogleServiceAuthError& error) OVERRIDE;
  62
  63   // net::URLFetcherDelegate implementation.
  64   virtual void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE;
  65
  66  protected:
  67   // Template methods for sub-classes.
  68
  69   // Methods to help create HTTP request.
  70   virtual GURL CreateApiCallUrl() = 0;
  71   virtual std::string CreateApiCallBody() = 0;
  72
  73   // Sub-classes can expose an appropriate observer interface by implementing
  74   // these template methods.
  75   // Called when the API call finished successfully.
  76   virtual void ProcessApiCallSuccess(const net::URLFetcher* source) = 0;
  77   // Called when the API call failed.
  78   virtual void ProcessApiCallFailure(const net::URLFetcher* source) = 0;
  79   // Called when a new access token is generated.
  80   virtual void ProcessNewAccessToken(const std::string& access_token) = 0;
  81   virtual void ProcessMintAccessTokenFailure(
  82       const GoogleServiceAuthError& error) = 0;
  83
  84  private:
  85   enum State {
  86     INITIAL,
  87     API_CALL_STARTED,
  88     API_CALL_DONE,
  89     MINT_ACCESS_TOKEN_STARTED,
  90     MINT_ACCESS_TOKEN_DONE,
  91     ERROR_STATE
  92   };
  93
  94   friend class OAuth2ApiCallFlowTest;
  95   FRIEND_TEST_ALL_PREFIXES(OAuth2ApiCallFlowTest, CreateURLFetcher);
  96
  97   // Helper to create an instance of access token fetcher.
  98   // Caller owns the returned instance.
  99   // Note that this is virtual since it is mocked during unit testing.
 100   virtual OAuth2AccessTokenFetcher* CreateAccessTokenFetcher();
 101
 102   // Creates an instance of URLFetcher that does not send or save cookies.
 103   // Template method CreateApiCallUrl is used to get the URL.
 104   // Template method CreateApiCallBody is used to get the body.
 105   // The URLFether's method will be GET if body is empty, POST otherwise.
 106   // Caller owns the returned instance.
 107   // Note that this is virtual since it is mocked during unit testing.
 108   virtual net::URLFetcher* CreateURLFetcher();
 109
 110   // Helper methods to implement the state machine for the flow.
 111   void BeginApiCall();
 112   void EndApiCall(const net::URLFetcher* source);
 113   void BeginMintAccessToken();
 114   void EndMintAccessToken(const GoogleServiceAuthError* error);
 115
 116   net::URLRequestContextGetter* context_;
 117   std::string refresh_token_;
 118   std::string access_token_;
 119   std::vector<std::string> scopes_;
 120
 121   // Override values for the main chrome client id and secret.
 122   std::string chrome_client_id_;
 123   std::string chrome_client_secret_;
 124
 125   State state_;
 126   // Whether we have already tried minting an access token once.
 127   bool tried_mint_access_token_;
 128
 129   scoped_ptr<net::URLFetcher> url_fetcher_;
 130   scoped_ptr<OAuth2AccessTokenFetcher> oauth2_access_token_fetcher_;
 131
 132   DISALLOW_COPY_AND_ASSIGN(OAuth2ApiCallFlow);
 133 };
 134
 135 #endif  // GOOGLE_APIS_GAIA_OAUTH2_API_CALL_FLOW_H_