extensions/renderer/resources/mime_handler_private_custom_bindings.js

   1 // Copyright 2015 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 /**
   6  * Custom bindings for the mime handler API.
   7  */
   8
   9 var binding = require('binding').Binding.create('mimeHandlerPrivate');
  10
  11 var NO_STREAM_ERROR =
  12     'Streams are only available from a mime handler view guest.';
  13 var STREAM_ABORTED_ERROR = 'Stream has been aborted.';
  14
  15 var servicePromise = Promise.all([
  16     requireAsync('content/public/renderer/service_provider'),
  17     requireAsync('extensions/common/api/mime_handler.mojom'),
  18     requireAsync('mojo/public/js/router'),
  19 ]).then(function(modules) {
  20   var serviceProvider = modules[0];
  21   var mojom = modules[1];
  22   var routerModule = modules[2];
  23   return new mojom.MimeHandlerService.proxyClass(new routerModule.Router(
  24       serviceProvider.connectToService(mojom.MimeHandlerService.name)));
  25 });
  26
  27 // Stores a promise to the GetStreamInfo() result to avoid making additional
  28 // calls in response to getStreamInfo() calls.
  29 var streamInfoPromise;
  30
  31 function throwNoStreamError() {
  32   throw new Error(NO_STREAM_ERROR);
  33 }
  34
  35 function createStreamInfoPromise() {
  36   return servicePromise.then(function(service) {
  37     return service.getStreamInfo();
  38   }).then(function(result) {
  39     if (!result.stream_info)
  40       throw new Error(STREAM_ABORTED_ERROR);
  41     return result.stream_info;
  42   }, throwNoStreamError);
  43 }
  44
  45 function constructStreamInfoDict(streamInfo) {
  46   var headers = {};
  47   for (var header of streamInfo.response_headers) {
  48     headers[header[0]] = header[1];
  49   }
  50   return {
  51     mimeType: streamInfo.mime_type,
  52     originalUrl: streamInfo.original_url,
  53     streamUrl: streamInfo.stream_url,
  54     tabId: streamInfo.tab_id,
  55     embedded: !!streamInfo.embedded,
  56     responseHeaders: headers,
  57   };
  58 }
  59
  60 binding.registerCustomHook(function(bindingsAPI) {
  61   var apiFunctions = bindingsAPI.apiFunctions;
  62   apiFunctions.setHandleRequestWithPromise('getStreamInfo', function() {
  63     if (!streamInfoPromise)
  64       streamInfoPromise = createStreamInfoPromise();
  65     return streamInfoPromise.then(constructStreamInfoDict);
  66   });
  67
  68   apiFunctions.setHandleRequestWithPromise('abortStream', function() {
  69     return servicePromise.then(function(service) {
  70       return service.abortStream().then(function() {});
  71     }).catch(throwNoStreamError);
  72   });
  73 });
  74
  75 exports.binding = binding.generate();