chrome/renderer/resources/extensions/utils.js

   1 // Copyright (c) 2012 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 schemaRegistry = requireNative('schema_registry');
   6 var CHECK = requireNative('logging').CHECK;
   7 var WARNING = requireNative('logging').WARNING;
   8
   9 // An object forEach. Calls |f| with each (key, value) pair of |obj|, using
  10 // |self| as the target.
  11 function forEach(obj, f, self) {
  12   for (var key in obj) {
  13     if ($Object.hasOwnProperty(obj, key))
  14       $Function.call(f, self, key, obj[key]);
  15   }
  16 }
  17
  18 // Assuming |array_of_dictionaries| is structured like this:
  19 // [{id: 1, ... }, {id: 2, ...}, ...], you can use
  20 // lookup(array_of_dictionaries, 'id', 2) to get the dictionary with id == 2.
  21 function lookup(array_of_dictionaries, field, value) {
  22   var filter = function (dict) {return dict[field] == value;};
  23   var matches = array_of_dictionaries.filter(filter);
  24   if (matches.length == 0) {
  25     return undefined;
  26   } else if (matches.length == 1) {
  27     return matches[0]
  28   } else {
  29     throw new Error("Failed lookup of field '" + field + "' with value '" +
  30                     value + "'");
  31   }
  32 }
  33
  34 function loadTypeSchema(typeName, defaultSchema) {
  35   var parts = $String.split(typeName, '.');
  36   if (parts.length == 1) {
  37     if (defaultSchema == null) {
  38       WARNING('Trying to reference "' + typeName + '" ' +
  39               'with neither namespace nor default schema.');
  40       return null;
  41     }
  42     var types = defaultSchema.types;
  43   } else {
  44     var schemaName = $Array.join($Array.slice(parts, 0, parts.length - 1), '.');
  45     var types = schemaRegistry.GetSchema(schemaName).types;
  46   }
  47   for (var i = 0; i < types.length; ++i) {
  48     if (types[i].id == typeName)
  49       return types[i];
  50   }
  51   return null;
  52 }
  53
  54 exports.forEach = forEach;
  55 exports.loadTypeSchema = loadTypeSchema;
  56 exports.lookup = lookup;