chrome/browser/safe_json_parser.cc

   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 #include "chrome/browser/safe_json_parser.h"
   6
   7 #include "chrome/common/chrome_utility_messages.h"
   8 #include "chrome/grit/generated_resources.h"
   9 #include "content/public/browser/browser_thread.h"
  10 #include "content/public/browser/utility_process_host.h"
  11 #include "ui/base/l10n/l10n_util.h"
  12
  13 using content::BrowserThread;
  14 using content::UtilityProcessHost;
  15
  16 SafeJsonParser::SafeJsonParser(const std::string& unsafe_json,
  17                                const SuccessCallback& success_callback,
  18                                const ErrorCallback& error_callback)
  19     : unsafe_json_(unsafe_json),
  20       success_callback_(success_callback),
  21       error_callback_(error_callback) {}
  22
  23 void SafeJsonParser::Start() {
  24   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  25   BrowserThread::PostTask(
  26       BrowserThread::IO,
  27       FROM_HERE,
  28       base::Bind(&SafeJsonParser::StartWorkOnIOThread, this));
  29 }
  30
  31 SafeJsonParser::~SafeJsonParser() {}
  32
  33 void SafeJsonParser::StartWorkOnIOThread() {
  34   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  35   UtilityProcessHost* host =
  36       UtilityProcessHost::Create(this, base::MessageLoopProxy::current().get());
  37   host->SetName(l10n_util::GetStringUTF16(
  38       IDS_UTILITY_PROCESS_JSON_PARSER_NAME));
  39   host->Send(new ChromeUtilityMsg_ParseJSON(unsafe_json_));
  40 }
  41
  42 void SafeJsonParser::OnJSONParseSucceeded(const base::ListValue& wrapper) {
  43   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  44   const base::Value* value = NULL;
  45   CHECK(wrapper.Get(0, &value));
  46
  47   parsed_json_.reset(value->DeepCopy());
  48   ReportResults();
  49 }
  50
  51 void SafeJsonParser::OnJSONParseFailed(const std::string& error_message) {
  52   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  53   error_ = error_message;
  54   ReportResults();
  55 }
  56
  57 void SafeJsonParser::ReportResults() {
  58   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  59
  60   BrowserThread::PostTask(
  61       BrowserThread::UI,
  62       FROM_HERE,
  63       base::Bind(&SafeJsonParser::ReportResultOnUIThread, this));
  64 }
  65
  66 void SafeJsonParser::ReportResultOnUIThread() {
  67   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  68   if (error_.empty() && parsed_json_) {
  69     if (!success_callback_.is_null())
  70       success_callback_.Run(parsed_json_.Pass());
  71   } else {
  72     if (!error_callback_.is_null())
  73       error_callback_.Run(error_);
  74   }
  75 }
  76
  77 bool SafeJsonParser::OnMessageReceived(const IPC::Message& message) {
  78   bool handled = true;
  79   IPC_BEGIN_MESSAGE_MAP(SafeJsonParser, message)
  80     IPC_MESSAGE_HANDLER(ChromeUtilityHostMsg_ParseJSON_Succeeded,
  81                         OnJSONParseSucceeded)
  82     IPC_MESSAGE_HANDLER(ChromeUtilityHostMsg_ParseJSON_Failed,
  83                         OnJSONParseFailed)
  84     IPC_MESSAGE_UNHANDLED(handled = false)
  85   IPC_END_MESSAGE_MAP()
  86   return handled;
  87 }