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