extensions/renderer/resources/permissions_custom_bindings.js

// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Custom binding for the Permissions API.

var binding = apiBridge || require('binding').Binding.create('permissions');

var registerArgumentMassager = bindingUtil ?
    $Function.bind(bindingUtil.registerEventArgumentMassager, bindingUtil) :
    require('event_bindings').registerArgumentMassager;

function maybeConvertToObject(str) {
  var parts = $String.split(str, '|');
  if (parts.length != 2)
    return str;

  var ret = {};
  ret[parts[0]] = $JSON.parse(parts[1]);
  return ret;
}

function massager(args, dispatch) {
  // Convert complex permissions back to objects for events.
  for (var i = 0; i < args[0].permissions.length; ++i)
    args[0].permissions[i] = maybeConvertToObject(args[0].permissions[i]);
  dispatch(args);
}

registerArgumentMassager('permissions.onAdded', massager);
registerArgumentMassager('permissions.onRemoved', massager);

// These custom binding are only necessary because it is not currently
// possible to have a union of types as the type of the items in an array.
// Once that is fixed, this entire file should go away.
// See,
// https://code.google.com/p/chromium/issues/detail?id=162044
// https://code.google.com/p/chromium/issues/detail?id=162042
// TODO(bryeung): delete this file.
binding.registerCustomHook(function(api) {
  var apiFunctions = api.apiFunctions;
  var permissions = api.compiledApi;

  function convertObjectPermissionsToStrings() {
    if (arguments.length < 1)
      return arguments;

    var args = arguments[0].permissions;
    if (!args)
      return arguments;

    for (var i = 0; i < args.length; ++i) {
      if (typeof args[i] == 'object') {
        var a = args[i];
        var keys = $Object.keys(a);
        if (keys.length != 1) {
          throw new Error('Too many keys in object-style permission.');
        }
        arguments[0].permissions[i] =
            keys[0] + '|' + $JSON.stringify(a[keys[0]]);
      }
    }

    return arguments;
  }

  // Convert complex permissions to strings so they validate against the schema
  apiFunctions.setUpdateArgumentsPreValidate(
      'contains', convertObjectPermissionsToStrings);
  apiFunctions.setUpdateArgumentsPreValidate(
      'remove', convertObjectPermissionsToStrings);
  apiFunctions.setUpdateArgumentsPreValidate(
      'request', convertObjectPermissionsToStrings);

  // Convert complex permissions back to objects
  apiFunctions.setCustomCallback('getAll',
      function(name, request, callback, response) {
        for (var i = 0; i < response.permissions.length; i += 1) {
          response.permissions[i] =
              maybeConvertToObject(response.permissions[i]);
        }

        // Since the schema says Permissions.permissions contains strings and
        // not objects, validation will fail after the for-loop above.  This
        // skips validation and calls the callback directly.
        if (callback)
          callback(response);
      });
});

if (!apiBridge)
  exports.$set('binding', binding.generate());