extensions/renderer/resources/send_request.js

   1 // Copyright 2014 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 var exceptionHandler = require('uncaught_exception_handler');
   6 var lastError = require('lastError');
   7 var logging = requireNative('logging');
   8 var natives = requireNative('sendRequest');
   9 var validate = require('schemaUtils').validate;
  10
  11 // All outstanding requests from sendRequest().
  12 var requests = {};
  13
  14 // Used to prevent double Activity Logging for API calls that use both custom
  15 // bindings and ExtensionFunctions (via sendRequest).
  16 var calledSendRequest = false;
  17
  18 // Runs a user-supplied callback safely.
  19 function safeCallbackApply(name, request, callback, args) {
  20   try {
  21     $Function.apply(callback, request, args);
  22   } catch (e) {
  23     exceptionHandler.handle('Error in response to ' + name, e, request.stack);
  24   }
  25 }
  26
  27 // Callback handling.
  28 function handleResponse(requestId, name, success, responseList, error) {
  29   // The chrome objects we will set lastError on. Really we should only be
  30   // setting this on the callback's chrome object, but set on ours too since
  31   // it's conceivable that something relies on that.
  32   var callerChrome = chrome;
  33
  34   try {
  35     var request = requests[requestId];
  36     logging.DCHECK(request != null);
  37
  38     // lastError needs to be set on the caller's chrome object no matter what,
  39     // though chances are it's the same as ours (it will be different when
  40     // calling API methods on other contexts).
  41     if (request.callback)
  42       callerChrome = natives.GetGlobal(request.callback).chrome;
  43
  44     lastError.clear(chrome);
  45     if (callerChrome !== chrome)
  46       lastError.clear(callerChrome);
  47
  48     if (!success) {
  49       if (!error)
  50         error = "Unknown error.";
  51       lastError.set(name, error, request.stack, chrome);
  52       if (callerChrome !== chrome)
  53         lastError.set(name, error, request.stack, callerChrome);
  54     }
  55
  56     if (request.customCallback) {
  57       safeCallbackApply(name,
  58                         request,
  59                         request.customCallback,
  60                         $Array.concat([name, request, request.callback],
  61                                       responseList));
  62     } else if (request.callback) {
  63       // Validate callback in debug only -- and only when the
  64       // caller has provided a callback. Implementations of api
  65       // calls may not return data if they observe the caller
  66       // has not provided a callback.
  67       if (logging.DCHECK_IS_ON() && !error) {
  68         if (!request.callbackSchema.parameters)
  69           throw new Error(name + ": no callback schema defined");
  70         validate(responseList, request.callbackSchema.parameters);
  71       }
  72       safeCallbackApply(name, request, request.callback, responseList);
  73     }
  74
  75     if (error && !lastError.hasAccessed(chrome)) {
  76       // The native call caused an error, but the developer might not have
  77       // checked runtime.lastError.
  78       lastError.reportIfUnchecked(name, callerChrome, request.stack);
  79     }
  80   } finally {
  81     delete requests[requestId];
  82     lastError.clear(chrome);
  83     if (callerChrome !== chrome)
  84       lastError.clear(callerChrome);
  85   }
  86 }
  87
  88 function prepareRequest(args, argSchemas) {
  89   var request = {};
  90   var argCount = args.length;
  91
  92   // Look for callback param.
  93   if (argSchemas.length > 0 &&
  94       argSchemas[argSchemas.length - 1].type == "function") {
  95     request.callback = args[args.length - 1];
  96     request.callbackSchema = argSchemas[argSchemas.length - 1];
  97     --argCount;
  98   }
  99
 100   request.args = [];
 101   for (var k = 0; k < argCount; k++) {
 102     request.args[k] = args[k];
 103   }
 104
 105   return request;
 106 }
 107
 108 // Send an API request and optionally register a callback.
 109 // |optArgs| is an object with optional parameters as follows:
 110 // - customCallback: a callback that should be called instead of the standard
 111 //   callback.
 112 // - nativeFunction: the v8 native function to handle the request, or
 113 //   StartRequest if missing.
 114 // - forIOThread: true if this function should be handled on the browser IO
 115 //   thread.
 116 // - preserveNullInObjects: true if it is safe for null to be in objects.
 117 // - stack: An optional string that contains the stack trace, to be displayed
 118 //   to the user if an error occurs.
 119 function sendRequest(functionName, args, argSchemas, optArgs) {
 120   calledSendRequest = true;
 121   if (!optArgs)
 122     optArgs = {};
 123   var request = prepareRequest(args, argSchemas);
 124   request.stack = optArgs.stack || exceptionHandler.getExtensionStackTrace();
 125   if (optArgs.customCallback) {
 126     request.customCallback = optArgs.customCallback;
 127   }
 128
 129   var nativeFunction = optArgs.nativeFunction || natives.StartRequest;
 130
 131   var requestId = natives.GetNextRequestId();
 132   request.id = requestId;
 133   requests[requestId] = request;
 134
 135   var hasCallback = request.callback || optArgs.customCallback;
 136   return nativeFunction(functionName,
 137                         request.args,
 138                         requestId,
 139                         hasCallback,
 140                         optArgs.forIOThread,
 141                         optArgs.preserveNullInObjects);
 142 }
 143
 144 function getCalledSendRequest() {
 145   return calledSendRequest;
 146 }
 147
 148 function clearCalledSendRequest() {
 149   calledSendRequest = false;
 150 }
 151
 152 exports.sendRequest = sendRequest;
 153 exports.getCalledSendRequest = getCalledSendRequest;
 154 exports.clearCalledSendRequest = clearCalledSendRequest;
 155 exports.safeCallbackApply = safeCallbackApply;
 156
 157 // Called by C++.
 158 exports.handleResponse = handleResponse;