chrome/browser/safe_json_parser.h

   1 // Copyright 2013 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 CHROME_BROWSER_SAFE_JSON_PARSER_H_
   6 #define CHROME_BROWSER_SAFE_JSON_PARSER_H_
   7
   8 #include <string>
   9
  10 #include "base/basictypes.h"
  11 #include "base/callback.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "content/public/browser/utility_process_host_client.h"
  14
  15 namespace base {
  16 class ListValue;
  17 class Value;
  18 }
  19
  20 namespace IPC {
  21 class Message;
  22 }
  23
  24 // SafeJsonParser parses a given JSON safely via a utility process. The object
  25 // is ref-counted and kept alive after Start() is called until one of the two
  26 // callbacks is called.
  27 class SafeJsonParser : public content::UtilityProcessHostClient {
  28  public:
  29   typedef base::Callback<void(scoped_ptr<base::Value>)> SuccessCallback;
  30   typedef base::Callback<void(const std::string&)> ErrorCallback;
  31
  32   SafeJsonParser(const std::string& unsafe_json,
  33                  const SuccessCallback& success_callback,
  34                  const ErrorCallback& error_callback);
  35
  36   void Start();
  37
  38  private:
  39   virtual ~SafeJsonParser();
  40
  41   void StartWorkOnIOThread();
  42
  43   void OnJSONParseSucceeded(const base::ListValue& wrapper);
  44   void OnJSONParseFailed(const std::string& error_message);
  45
  46   void ReportResults();
  47   void ReportResultOnUIThread();
  48
  49   // Implementing pieces of the UtilityProcessHostClient interface.
  50   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
  51
  52   const std::string unsafe_json_;
  53   SuccessCallback success_callback_;
  54   ErrorCallback error_callback_;
  55
  56   scoped_ptr<base::Value> parsed_json_;
  57   std::string error_;
  58
  59   DISALLOW_COPY_AND_ASSIGN(SafeJsonParser);
  60 };
  61
  62 #endif  // CHROME_BROWSER_SAFE_JSON_PARSER_H_