// Copyright 2006 The Closure Library Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS-IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
/**
* @fileoverview Bootstrap for the Google JS Library (Closure).
*
* In uncompiled mode base.js will write out Closure's deps file, unless the
* global <code>CLOSURE_NO_DEPS</code> is set to true. This allows projects to
* include their own deps file(s) from different locations.
*
*
* @provideGoog
*/
/**
* @define {boolean} Overridden to true by the compiler when --closure_pass
* or --mark_as_compiled is specified.
*/
var COMPILED = false;
/**
* Base namespace for the Closure library. Checks to see goog is already
* defined in the current scope before assigning to prevent clobbering if
* base.js is loaded more than once.
*
* @const
*/
var goog = goog || {};
/**
* Reference to the global context. In most cases this will be 'window'.
*/
goog.global = this;
/**
* A hook for overriding the define values in uncompiled mode.
*
* In uncompiled mode, {@code CLOSURE_UNCOMPILED_DEFINES} may be defined before
* loading base.js. If a key is defined in {@code CLOSURE_UNCOMPILED_DEFINES},
* {@code goog.define} will use the value instead of the default value. This
* allows flags to be overwritten without compilation (this is normally
* accomplished with the compiler's "define" flag).
*
* Example:
* <pre>
* var CLOSURE_UNCOMPILED_DEFINES = {'goog.DEBUG': false};
* </pre>
*
* @type {Object.<string, (string|number|boolean)>|undefined}
*/
goog.global.CLOSURE_UNCOMPILED_DEFINES;
/**
* A hook for overriding the define values in uncompiled or compiled mode,
* like CLOSURE_UNCOMPILED_DEFINES but effective in compiled code. In
* uncompiled code CLOSURE_UNCOMPILED_DEFINES takes precedence.
*
* Also unlike CLOSURE_UNCOMPILED_DEFINES the values must be number, boolean or
* string literals or the compiler will emit an error.
*
* While any @define value may be set, only those set with goog.define will be
* effective for uncompiled code.
*
* Example:
* <pre>
* var CLOSURE_DEFINES = {'goog.DEBUG': false};
* </pre>
*
* @type {Object.<string, (string|number|boolean)>|undefined}
*/
goog.global.CLOSURE_DEFINES;
/**
* Returns true if the specified value is not undefined.
* WARNING: Do not use this to test if an object has a property. Use the in
* operator instead.
*
* @param {?} val Variable to test.
* @return {boolean} Whether variable is defined.
*/
goog.isDef = function(val) {
// void 0 always evaluates to undefined and hence we do not need to depend on
// the definition of the global variable named 'undefined'.
return val !== void 0;
};
/**
* Builds an object structure for the provided namespace path, ensuring that
* names that already exist are not overwritten. For example:
* "a.b.c" -> a = {};a.b={};a.b.c={};
* Used by goog.provide and goog.exportSymbol.
* @param {string} name name of the object that this file defines.
* @param {*=} opt_object the object to expose at the end of the path.
* @param {Object=} opt_objectToExportTo The object to add the path to; default
* is |goog.global|.
* @private
*/
goog.exportPath_ = function(name, opt_object, opt_objectToExportTo) {
var parts = name.split('.');
var cur = opt_objectToExportTo || goog.global;
// Internet Explorer exhibits strange behavior when throwing errors from
// methods externed in this manner. See the testExportSymbolExceptions in
// base_test.html for an example.
if (!(parts[0] in cur) && cur.execScript) {
cur.execScript('var ' + parts[0]);
}
// Certain browsers cannot parse code in the form for((a in b); c;);
// This pattern is produced by the JSCompiler when it collapses the
// statement above into the conditional loop below. To prevent this from
// happening, use a for-loop and reserve the init logic as below.
// Parentheses added to eliminate strict JS warning in Firefox.
for (var part; parts.length && (part = parts.shift());) {
if (!parts.length && goog.isDef(opt_object)) {
// last part and we have an object; use it
cur[part] = opt_object;
} else if (cur[part]) {
cur = cur[part];
} else {
cur = cur[part] = {};
}
}
};
/**
* Defines a named value. In uncompiled mode, the value is retreived from
* CLOSURE_DEFINES or CLOSURE_UNCOMPILED_DEFINES if the object is defined and
* has the property specified, and otherwise used the defined defaultValue.
* When compiled, the default can be overridden using compiler command-line
* options.
*
* @param {string} name The distinguished name to provide.
* @param {string|number|boolean} defaultValue
*/
goog.define = function(name, defaultValue) {
var value = defaultValue;
if (!COMPILED) {
if (goog.global.CLOSURE_UNCOMPILED_DEFINES &&
Object.prototype.hasOwnProperty.call(
goog.global.CLOSURE_UNCOMPILED_DEFINES, name)) {
value = goog.global.CLOSURE_UNCOMPILED_DEFINES[name];
} else if (goog.global.CLOSURE_DEFINES &&
Object.prototype.hasOwnProperty.call(
goog.global.CLOSURE_DEFINES, name)) {
value = goog.global.CLOSURE_DEFINES[name];
}
}
goog.exportPath_(name, value);
};
/**
* @define {boolean} DEBUG is provided as a convenience so that debugging code
* that should not be included in a production js_binary can be easily stripped
* by specifying --define goog.DEBUG=false to the JSCompiler. For example, most
* toString() methods should be declared inside an "if (goog.DEBUG)" conditional
* because they are generally used for debugging purposes and it is difficult
* for the JSCompiler to statically determine whether they are used.
*/
goog.DEBUG = true;
/**
* @define {string} LOCALE defines the locale being used for compilation. It is
* used to select locale specific data to be compiled in js binary. BUILD rule
* can specify this value by "--define goog.LOCALE=<locale_name>" as JSCompiler
* option.
*
* Take into account that the locale code format is important. You should use
* the canonical Unicode format with hyphen as a delimiter. Language must be
* lowercase, Language Script - Capitalized, Region - UPPERCASE.
* There are few examples: pt-BR, en, en-US, sr-Latin-BO, zh-Hans-CN.
*
* See more info about locale codes here:
* http://www.unicode.org/reports/tr35/#Unicode_Language_and_Locale_Identifiers
*
* For language codes you should use values defined by ISO 693-1. See it here
* http://www.w3.org/WAI/ER/IG/ert/iso639.htm. There is only one exception from
* this rule: the Hebrew language. For legacy reasons the old code (iw) should
* be used instead of the new code (he), see http://wiki/Main/IIISynonyms.
*/
goog.define('goog.LOCALE', 'en'); // default to en
/**
* @define {boolean} Whether this code is running on trusted sites.
*
* On untrusted sites, several native functions can be defined or overridden by
* external libraries like Prototype, Datejs, and JQuery and setting this flag
* to false forces closure to use its own implementations when possible.
*
* If your JavaScript can be loaded by a third party site and you are wary about
* relying on non-standard implementations, specify
* "--define goog.TRUSTED_SITE=false" to the JSCompiler.
*/
goog.define('goog.TRUSTED_SITE', true);
/**
* @define {boolean} Whether a project is expected to be running in strict mode.
*
* This define can be used to trigger alternate implementations compatible with
* running in EcmaScript Strict mode or warn about unavailable functionality.
* See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions_and_function_scope/Strict_mode
*/
goog.define('goog.STRICT_MODE_COMPATIBLE', false);
/**
* Creates object stubs for a namespace. The presence of one or more
* goog.provide() calls indicate that the file defines the given
* objects/namespaces. Provided objects must not be null or undefined.
* Build tools also scan for provide/require statements
* to discern dependencies, build dependency files (see deps.js), etc.
* @see goog.require
* @param {string} name Namespace provided by this file in the form
* "goog.package.part".
*/
goog.provide = function(name) {
if (!COMPILED) {
// Ensure that the same namespace isn't provided twice. This is intended
// to teach new developers that 'goog.provide' is effectively a variable
// declaration. And when JSCompiler transforms goog.provide into a real
// variable declaration, the compiled JS should work the same as the raw
// JS--even when the raw JS uses goog.provide incorrectly.
if (goog.isProvided_(name)) {
throw Error('Namespace "' + name + '" already declared.');
}
delete goog.implicitNamespaces_[name];
var namespace = name;
while ((namespace = namespace.substring(0, namespace.lastIndexOf('.')))) {
if (goog.getObjectByName(namespace)) {
break;
}
goog.implicitNamespaces_[namespace] = true;
}
}
goog.exportPath_(name);
};
/**
* Marks that the current file should only be used for testing, and never for
* live code in production.
*
* In the case of unit tests, the message may optionally be an exact namespace
* for the test (e.g. 'goog.stringTest'). The linter will then ignore the extra
* provide (if not explicitly defined in the code).
*
* @param {string=} opt_message Optional message to add to the error that's
* raised when used in production code.
*/
goog.setTestOnly = function(opt_message) {
if (COMPILED && !goog.DEBUG) {
opt_message = opt_message || '';
throw Error('Importing test-only code into non-debug environment' +
(opt_message ? ': ' + opt_message : '.'));
}
};
/**
* Forward declares a symbol. This is an indication to the compiler that the
* symbol may be used in the source yet is not required and may not be provided
* in compilation.
*
* The most common usage of forward declaration is code that takes a type as a
* function parameter but does not need to require it. By forward declaring
* instead of requiring, no hard dependency is made, and (if not required
* elsewhere) the namespace may never be required and thus, not be pulled
* into the JavaScript binary. If it is required elsewhere, it will be type
* checked as normal.
*
*
* @param {string} name The namespace to forward declare in the form of
* "goog.package.part".
*/
goog.forwardDeclare = function(name) {};
if (!COMPILED) {
/**
* Check if the given name has been goog.provided. This will return false for
* names that are available only as implicit namespaces.
* @param {string} name name of the object to look for.
* @return {boolean} Whether the name has been provided.
* @private
*/
goog.isProvided_ = function(name) {
return !goog.implicitNamespaces_[name] &&
goog.isDefAndNotNull(goog.getObjectByName(name));
};
/**
* Namespaces implicitly defined by goog.provide. For example,
* goog.provide('goog.events.Event') implicitly declares that 'goog' and
* 'goog.events' must be namespaces.
*
* @type {Object}
* @private
*/
goog.implicitNamespaces_ = {};
}
/**
* Returns an object based on its fully qualified external name. The object
* is not found if null or undefined. If you are using a compilation pass that
* renames property names beware that using this function will not find renamed
* properties.
*
* @param {string} name The fully qualified name.
* @param {Object=} opt_obj The object within which to look; default is
* |goog.global|.
* @return {?} The value (object or primitive) or, if not found, null.
*/
goog.getObjectByName = function(name, opt_obj) {
var parts = name.split('.');
var cur = opt_obj || goog.global;
for (var part; part = parts.shift(); ) {
if (goog.isDefAndNotNull(cur[part])) {
cur = cur[part];
} else {
return null;
}
}
return cur;
};
/**
* Globalizes a whole namespace, such as goog or goog.lang.
*
* @param {Object} obj The namespace to globalize.
* @param {Object=} opt_global The object to add the properties to.
* @deprecated Properties may be explicitly exported to the global scope, but
* this should no longer be done in bulk.
*/
goog.globalize = function(obj, opt_global) {
var global = opt_global || goog.global;
for (var x in obj) {
global[x] = obj[x];
}
};
/**
* Adds a dependency from a file to the files it requires.
* @param {string} relPath The path to the js file.
* @param {Array} provides An array of strings with the names of the objects
* this file provides.
* @param {Array} requires An array of strings with the names of the objects
* this file requires.
*/
goog.addDependency = function(relPath, provides, requires) {
if (goog.DEPENDENCIES_ENABLED) {
var provide, require;
var path = relPath.replace(/\\/g, '/');
var deps = goog.dependencies_;
for (var i = 0; provide = provides[i]; i++) {
deps.nameToPath[provide] = path;
if (!(path in deps.pathToNames)) {
deps.pathToNames[path] = {};
}
deps.pathToNames[path][provide] = true;
}
for (var j = 0; require = requires[j]; j++) {
if (!(path in deps.requires)) {
deps.requires[path] = {};
}
deps.requires[path][require] = true;
}
}
};
// NOTE(nnaze): The debug DOM loader was included in base.js as an original way
// to do "debug-mode" development. The dependency system can sometimes be
// confusing, as can the debug DOM loader's asynchronous nature.
//
// With the DOM loader, a call to goog.require() is not blocking -- the script
// will not load until some point after the current script. If a namespace is
// needed at runtime, it needs to be defined in a previous script, or loaded via
// require() with its registered dependencies.
// User-defined namespaces may need their own deps file. See http://go/js_deps,
// http://go/genjsdeps, or, externally, DepsWriter.
// https://developers.google.com/closure/library/docs/depswriter
//
// Because of legacy clients, the DOM loader can't be easily removed from
// base.js. Work is being done to make it disableable or replaceable for
// different environments (DOM-less JavaScript interpreters like Rhino or V8,
// for example). See bootstrap/ for more information.
/**
* @define {boolean} Whether to enable the debug loader.
*
* If enabled, a call to goog.require() will attempt to load the namespace by
* appending a script tag to the DOM (if the namespace has been registered).
*
* If disabled, goog.require() will simply assert that the namespace has been
* provided (and depend on the fact that some outside tool correctly ordered
* the script).
*/
goog.define('goog.ENABLE_DEBUG_LOADER', true);
/**
* Implements a system for the dynamic resolution of dependencies that works in
* parallel with the BUILD system. Note that all calls to goog.require will be
* stripped by the JSCompiler when the --closure_pass option is used.
* @see goog.provide
* @param {string} name Namespace to include (as was given in goog.provide()) in
* the form "goog.package.part".
*/
goog.require = function(name) {
// If the object already exists we do not need do do anything.
// TODO(arv): If we start to support require based on file name this has to
// change.
// TODO(arv): If we allow goog.foo.* this has to change.
// TODO(arv): If we implement dynamic load after page load we should probably
// not remove this code for the compiled output.
if (!COMPILED) {
if (goog.isProvided_(name)) {
return;
}
if (goog.ENABLE_DEBUG_LOADER) {
var path = goog.getPathFromDeps_(name);
if (path) {
goog.included_[path] = true;
goog.writeScripts_();
return;
}
}
var errorMessage = 'goog.require could not find: ' + name;
if (goog.global.console) {
goog.global.console['error'](errorMessage);
}
throw Error(errorMessage);
}
};
/**
* Path for included scripts.
* @type {string}
*/
goog.basePath = '';
/**
* A hook for overriding the base path.
* @type {string|undefined}
*/
goog.global.CLOSURE_BASE_PATH;
/**
* Whether to write out Closure's deps file. By default, the deps are written.
* @type {boolean|undefined}
*/
goog.global.CLOSURE_NO_DEPS;
/**
* A function to import a single script. This is meant to be overridden when
* Closure is being run in non-HTML contexts, such as web workers. It's defined
* in the global scope so that it can be set before base.js is loaded, which
* allows deps.js to be imported properly.
*
* The function is passed the script source, which is a relative URI. It should
* return true if the script was imported, false otherwise.
* @type {(function(string): boolean)|undefined}
*/
goog.global.CLOSURE_IMPORT_SCRIPT;
/**
* Null function used for default values of callbacks, etc.
* @return {void} Nothing.
*/
goog.nullFunction = function() {};
/**
* The identity function. Returns its first argument.
*
* @param {*=} opt_returnValue The single value that will be returned.
* @param {...*} var_args Optional trailing arguments. These are ignored.
* @return {?} The first argument. We can't know the type -- just pass it along
* without type.
* @deprecated Use goog.functions.identity instead.
*/
goog.identityFunction = function(opt_returnValue, var_args) {
return opt_returnValue;
};
/**
* When defining a class Foo with an abstract method bar(), you can do:
* Foo.prototype.bar = goog.abstractMethod
*
* Now if a subclass of Foo fails to override bar(), an error will be thrown
* when bar() is invoked.
*
* Note: This does not take the name of the function to override as an argument
* because that would make it more difficult to obfuscate our JavaScript code.
*
* @type {!Function}
* @throws {Error} when invoked to indicate the method should be overridden.
*/
goog.abstractMethod = function() {
throw Error('unimplemented abstract method');
};
/**
* Adds a {@code getInstance} static method that always returns the same
* instance object.
* @param {!Function} ctor The constructor for the class to add the static
* method to.
*/
goog.addSingletonGetter = function(ctor) {
ctor.getInstance = function() {
if (ctor.instance_) {
return ctor.instance_;
}
if (goog.DEBUG) {
// NOTE: JSCompiler can't optimize away Array#push.
goog.instantiatedSingletons_[goog.instantiatedSingletons_.length] = ctor;
}
return ctor.instance_ = new ctor;
};
};
/**
* All singleton classes that have been instantiated, for testing. Don't read
* it directly, use the {@code goog.testing.singleton} module. The compiler
* removes this variable if unused.
* @type {!Array.<!Function>}
* @private
*/
goog.instantiatedSingletons_ = [];
/**
* True if goog.dependencies_ is available.
* @const {boolean}
*/
goog.DEPENDENCIES_ENABLED = !COMPILED && goog.ENABLE_DEBUG_LOADER;
if (goog.DEPENDENCIES_ENABLED) {
/**
* Object used to keep track of urls that have already been added. This record
* allows the prevention of circular dependencies.
* @type {Object}
* @private
*/
goog.included_ = {};
/**
* This object is used to keep track of dependencies and other data that is
* used for loading scripts.
* @private
* @type {Object}
*/
goog.dependencies_ = {
pathToNames: {}, // 1 to many
nameToPath: {}, // 1 to 1
requires: {}, // 1 to many
// Used when resolving dependencies to prevent us from visiting file twice.
visited: {},
written: {} // Used to keep track of script files we have written.
};
/**
* Tries to detect whether is in the context of an HTML document.
* @return {boolean} True if it looks like HTML document.
* @private
*/
goog.inHtmlDocument_ = function() {
var doc = goog.global.document;
return typeof doc != 'undefined' &&
'write' in doc; // XULDocument misses write.
};
/**
* Tries to detect the base path of base.js script that bootstraps Closure.
* @private
*/
goog.findBasePath_ = function() {
if (goog.global.CLOSURE_BASE_PATH) {
goog.basePath = goog.global.CLOSURE_BASE_PATH;
return;
} else if (!goog.inHtmlDocument_()) {
return;
}
var doc = goog.global.document;
var scripts = doc.getElementsByTagName('script');
// Search backwards since the current script is in almost all cases the one
// that has base.js.
for (var i = scripts.length - 1; i >= 0; --i) {
var src = scripts[i].src;
var qmark = src.lastIndexOf('?');
var l = qmark == -1 ? src.length : qmark;
if (src.substr(l - 7, 7) == 'base.js') {
goog.basePath = src.substr(0, l - 7);
return;
}
}
};
/**
* Imports a script if, and only if, that script hasn't already been imported.
* (Must be called at execution time)
* @param {string} src Script source.
* @private
*/
goog.importScript_ = function(src) {
var importScript = goog.global.CLOSURE_IMPORT_SCRIPT ||
goog.writeScriptTag_;
if (!goog.dependencies_.written[src] && importScript(src)) {
goog.dependencies_.written[src] = true;
}
};
/**
* The default implementation of the import function. Writes a script tag to
* import the script.
*
* @param {string} src The script source.
* @return {boolean} True if the script was imported, false otherwise.
* @private
*/
goog.writeScriptTag_ = function(src) {
if (goog.inHtmlDocument_()) {
var doc = goog.global.document;
// If the user tries to require a new symbol after document load,
// something has gone terribly wrong. Doing a document.write would
// wipe out the page.
if (doc.readyState == 'complete') {
// Certain test frameworks load base.js multiple times, which tries
// to write deps.js each time. If that happens, just fail silently.
// These frameworks wipe the page between each load of base.js, so this
// is OK.
var isDeps = /\bdeps.js$/.test(src);
if (isDeps) {
return false;
} else {
throw Error('Cannot write "' + src + '" after document load');
}
}
doc.write(
'<script type="text/javascript" src="' + src + '"></' + 'script>');
return true;
} else {
return false;
}
};
/**
* Resolves dependencies based on the dependencies added using addDependency
* and calls importScript_ in the correct order.
* @private
*/
goog.writeScripts_ = function() {
// The scripts we need to write this time.
var scripts = [];
var seenScript = {};
var deps = goog.dependencies_;
function visitNode(path) {
if (path in deps.written) {
return;
}
// We have already visited this one. We can get here if we have cyclic
// dependencies.
if (path in deps.visited) {
if (!(path in seenScript)) {
seenScript[path] = true;
scripts.push(path);
}
return;
}
deps.visited[path] = true;
if (path in deps.requires) {
for (var requireName in deps.requires[path]) {
// If the required name is defined, we assume that it was already
// bootstrapped by other means.
if (!goog.isProvided_(requireName)) {
if (requireName in deps.nameToPath) {
visitNode(deps.nameToPath[requireName]);
} else {
throw Error('Undefined nameToPath for ' + requireName);
}
}
}
}
if (!(path in seenScript)) {
seenScript[path] = true;
scripts.push(path);
}
}
for (var path in goog.included_) {
if (!deps.written[path]) {
visitNode(path);
}
}
for (var i = 0; i < scripts.length; i++) {
if (scripts[i]) {
goog.importScript_(goog.basePath + scripts[i]);
} else {
throw Error('Undefined script input');
}
}
};
/**
* Looks at the dependency rules and tries to determine the script file that
* fulfills a particular rule.
* @param {string} rule In the form goog.namespace.Class or project.script.
* @return {?string} Url corresponding to the rule, or null.
* @private
*/
goog.getPathFromDeps_ = function(rule) {
if (rule in goog.dependencies_.nameToPath) {
return goog.dependencies_.nameToPath[rule];
} else {
return null;
}
};
goog.findBasePath_();
// Allow projects to manage the deps files themselves.
if (!goog.global.CLOSURE_NO_DEPS) {
goog.importScript_(goog.basePath + 'deps.js');
}
}
//==============================================================================
// Language Enhancements
//==============================================================================
/**
* This is a "fixed" version of the typeof operator. It differs from the typeof
* operator in such a way that null returns 'null' and arrays return 'array'.
* @param {*} value The value to get the type of.
* @return {string} The name of the type.
*/
goog.typeOf = function(value) {
var s = typeof value;
if (s == 'object') {
if (value) {
// Check these first, so we can avoid calling Object.prototype.toString if
// possible.
//
// IE improperly marshals tyepof across execution contexts, but a
// cross-context object will still return false for "instanceof Object".
if (value instanceof Array) {
return 'array';
} else if (value instanceof Object) {
return s;
}
// HACK: In order to use an Object prototype method on the arbitrary
// value, the compiler requires the value be cast to type Object,
// even though the ECMA spec explicitly allows it.
var className = Object.prototype.toString.call(
/** @type {Object} */ (value));
// In Firefox 3.6, attempting to access iframe window objects' length
// property throws an NS_ERROR_FAILURE, so we need to special-case it
// here.
if (className == '[object Window]') {
return 'object';
}
// We cannot always use constructor == Array or instanceof Array because
// different frames have different Array objects. In IE6, if the iframe
// where the array was created is destroyed, the array loses its
// prototype. Then dereferencing val.splice here throws an exception, so
// we can't use goog.isFunction. Calling typeof directly returns 'unknown'
// so that will work. In this case, this function will return false and
// most array functions will still work because the array is still
// array-like (supports length and []) even though it has lost its
// prototype.
// Mark Miller noticed that Object.prototype.toString
// allows access to the unforgeable [[Class]] property.
// 15.2.4.2 Object.prototype.toString ( )
// When the toString method is called, the following steps are taken:
// 1. Get the [[Class]] property of this object.
// 2. Compute a string value by concatenating the three strings
// "[object ", Result(1), and "]".
// 3. Return Result(2).
// and this behavior survives the destruction of the execution context.
if ((className == '[object Array]' ||
// In IE all non value types are wrapped as objects across window
// boundaries (not iframe though) so we have to do object detection
// for this edge case.
typeof value.length == 'number' &&
typeof value.splice != 'undefined' &&
typeof value.propertyIsEnumerable != 'undefined' &&
!value.propertyIsEnumerable('splice')
)) {
return 'array';
}
// HACK: There is still an array case that fails.
// function ArrayImpostor() {}
// ArrayImpostor.prototype = [];
// var impostor = new ArrayImpostor;
// this can be fixed by getting rid of the fast path
// (value instanceof Array) and solely relying on
// (value && Object.prototype.toString.vall(value) === '[object Array]')
// but that would require many more function calls and is not warranted
// unless closure code is receiving objects from untrusted sources.
// IE in cross-window calls does not correctly marshal the function type
// (it appears just as an object) so we cannot use just typeof val ==
// 'function'. However, if the object has a call property, it is a
// function.
if ((className == '[object Function]' ||
typeof value.call != 'undefined' &&
typeof value.propertyIsEnumerable != 'undefined' &&
!value.propertyIsEnumerable('call'))) {
return 'function';
}
} else {
return 'null';
}
} else if (s == 'function' && typeof value.call == 'undefined') {
// In Safari typeof nodeList returns 'function', and on Firefox typeof
// behaves similarly for HTML{Applet,Embed,Object}, Elements and RegExps. We
// would like to return object for those and we can detect an invalid
// function by making sure that the function object has a call method.
return 'object';
}
return s;
};
/**
* Returns true if the specified value is null.
* @param {?} val Variable to test.
* @return {boolean} Whether variable is null.
*/
goog.isNull = function(val) {
return val === null;
};
/**
* Returns true if the specified value is defined and not null.
* @param {?} val Variable to test.
* @return {boolean} Whether variable is defined and not null.
*/
goog.isDefAndNotNull = function(val) {
// Note that undefined == null.
return val != null;
};
/**
* Returns true if the specified value is an array.
* @param {?} val Variable to test.
* @return {boolean} Whether variable is an array.
*/
goog.isArray = function(val) {
return goog.typeOf(val) == 'array';
};
/**
* Returns true if the object looks like an array. To qualify as array like
* the value needs to be either a NodeList or an object with a Number length
* property.
* @param {?} val Variable to test.
* @return {boolean} Whether variable is an array.
*/
goog.isArrayLike = function(val) {
var type = goog.typeOf(val);
return type == 'array' || type == 'object' && typeof val.length == 'number';
};
/**
* Returns true if the object looks like a Date. To qualify as Date-like the
* value needs to be an object and have a getFullYear() function.
* @param {?} val Variable to test.
* @return {boolean} Whether variable is a like a Date.
*/
goog.isDateLike = function(val) {
return goog.isObject(val) && typeof val.getFullYear == 'function';
};
/**
* Returns true if the specified value is a string.
* @param {?} val Variable to test.
* @return {boolean} Whether variable is a string.
*/
goog.isString = function(val) {
return typeof val == 'string';
};
/**
* Returns true if the specified value is a boolean.
* @param {?} val Variable to test.
* @return {boolean} Whether variable is boolean.
*/
goog.isBoolean = function(val) {
return typeof val == 'boolean';
};
/**
* Returns true if the specified value is a number.
* @param {?} val Variable to test.
* @return {boolean} Whether variable is a number.
*/
goog.isNumber = function(val) {
return typeof val == 'number';
};
/**
* Returns true if the specified value is a function.
* @param {?} val Variable to test.
* @return {boolean} Whether variable is a function.
*/
goog.isFunction = function(val) {
return goog.typeOf(val) == 'function';
};
/**
* Returns true if the specified value is an object. This includes arrays and
* functions.
* @param {?} val Variable to test.
* @return {boolean} Whether variable is an object.
*/
goog.isObject = function(val) {
var type = typeof val;
return type == 'object' && val != null || type == 'function';
// return Object(val) === val also works, but is slower, especially if val is
// not an object.
};
/**
* Gets a unique ID for an object. This mutates the object so that further calls
* with the same object as a parameter returns the same value. The unique ID is
* guaranteed to be unique across the current session amongst objects that are
* passed into {@code getUid}. There is no guarantee that the ID is unique or
* consistent across sessions. It is unsafe to generate unique ID for function
* prototypes.
*
* @param {Object} obj The object to get the unique ID for.
* @return {number} The unique ID for the object.
*/
goog.getUid = function(obj) {
// TODO(arv): Make the type stricter, do not accept null.
// In Opera window.hasOwnProperty exists but always returns false so we avoid
// using it. As a consequence the unique ID generated for BaseClass.prototype
// and SubClass.prototype will be the same.
return obj[goog.UID_PROPERTY_] ||
(obj[goog.UID_PROPERTY_] = ++goog.uidCounter_);
};
/**
* Whether the given object is alreay assigned a unique ID.
*
* This does not modify the object.
*
* @param {Object} obj The object to check.
* @return {boolean} Whether there an assigned unique id for the object.
*/
goog.hasUid = function(obj) {
return !!obj[goog.UID_PROPERTY_];
};
/**
* Removes the unique ID from an object. This is useful if the object was
* previously mutated using {@code goog.getUid} in which case the mutation is
* undone.
* @param {Object} obj The object to remove the unique ID field from.
*/
goog.removeUid = function(obj) {
// TODO(arv): Make the type stricter, do not accept null.
// In IE, DOM nodes are not instances of Object and throw an exception if we
// try to delete. Instead we try to use removeAttribute.
if ('removeAttribute' in obj) {
obj.removeAttribute(goog.UID_PROPERTY_);
}
/** @preserveTry */
try {
delete obj[goog.UID_PROPERTY_];
} catch (ex) {
}
};
/**
* Name for unique ID property. Initialized in a way to help avoid collisions
* with other closure JavaScript on the same page.
* @type {string}
* @private
*/
goog.UID_PROPERTY_ = 'closure_uid_' + ((Math.random() * 1e9) >>> 0);
/**
* Counter for UID.
* @type {number}
* @private
*/
goog.uidCounter_ = 0;
/**
* Adds a hash code field to an object. The hash code is unique for the
* given object.
* @param {Object} obj The object to get the hash code for.
* @return {number} The hash code for the object.
* @deprecated Use goog.getUid instead.
*/
goog.getHashCode = goog.getUid;
/**
* Removes the hash code field from an object.
* @param {Object} obj The object to remove the field from.
* @deprecated Use goog.removeUid instead.
*/
goog.removeHashCode = goog.removeUid;
/**
* Clones a value. The input may be an Object, Array, or basic type. Objects and
* arrays will be cloned recursively.
*
* WARNINGS:
* <code>goog.cloneObject</code> does not detect reference loops. Objects that
* refer to themselves will cause infinite recursion.
*
* <code>goog.cloneObject</code> is unaware of unique identifiers, and copies
* UIDs created by <code>getUid</code> into cloned results.
*
* @param {*} obj The value to clone.
* @return {*} A clone of the input value.
* @deprecated goog.cloneObject is unsafe. Prefer the goog.object methods.
*/
goog.cloneObject = function(obj) {
var type = goog.typeOf(obj);
if (type == 'object' || type == 'array') {
if (obj.clone) {
return obj.clone();
}
var clone = type == 'array' ? [] : {};
for (var key in obj) {
clone[key] = goog.cloneObject(obj[key]);
}
return clone;
}
return obj;
};
/**
* A native implementation of goog.bind.
* @param {Function} fn A function to partially apply.
* @param {Object|undefined} selfObj Specifies the object which this should
* point to when the function is run.
* @param {...*} var_args Additional arguments that are partially applied to the
* function.
* @return {!Function} A partially-applied form of the function bind() was
* invoked as a method of.
* @private
* @suppress {deprecated} The compiler thinks that Function.prototype.bind is
* deprecated because some people have declared a pure-JS version.
* Only the pure-JS version is truly deprecated.
*/
goog.bindNative_ = function(fn, selfObj, var_args) {
return /** @type {!Function} */ (fn.call.apply(fn.bind, arguments));
};
/**
* A pure-JS implementation of goog.bind.
* @param {Function} fn A function to partially apply.
* @param {Object|undefined} selfObj Specifies the object which this should
* point to when the function is run.
* @param {...*} var_args Additional arguments that are partially applied to the
* function.
* @return {!Function} A partially-applied form of the function bind() was
* invoked as a method of.
* @private
*/
goog.bindJs_ = function(fn, selfObj, var_args) {
if (!fn) {
throw new Error();
}
if (arguments.length > 2) {
var boundArgs = Array.prototype.slice.call(arguments, 2);
return function() {
// Prepend the bound arguments to the current arguments.
var newArgs = Array.prototype.slice.call(arguments);
Array.prototype.unshift.apply(newArgs, boundArgs);
return fn.apply(selfObj, newArgs);
};
} else {
return function() {
return fn.apply(selfObj, arguments);
};
}
};
/**
* Partially applies this function to a particular 'this object' and zero or
* more arguments. The result is a new function with some arguments of the first
* function pre-filled and the value of this 'pre-specified'.
*
* Remaining arguments specified at call-time are appended to the pre-specified
* ones.
*
* Also see: {@link #partial}.
*
* Usage:
* <pre>var barMethBound = bind(myFunction, myObj, 'arg1', 'arg2');
* barMethBound('arg3', 'arg4');</pre>
*
* @param {?function(this:T, ...)} fn A function to partially apply.
* @param {T} selfObj Specifies the object which this should point to when the
* function is run.
* @param {...*} var_args Additional arguments that are partially applied to the
* function.
* @return {!Function} A partially-applied form of the function bind() was
* invoked as a method of.
* @template T
* @suppress {deprecated} See above.
*/
goog.bind = function(fn, selfObj, var_args) {
// TODO(nicksantos): narrow the type signature.
if (Function.prototype.bind &&
// NOTE(nicksantos): Somebody pulled base.js into the default Chrome
// extension environment. This means that for Chrome extensions, they get
// the implementation of Function.prototype.bind that calls goog.bind
// instead of the native one. Even worse, we don't want to introduce a
// circular dependency between goog.bind and Function.prototype.bind, so
// we have to hack this to make sure it works correctly.
Function.prototype.bind.toString().indexOf('native code') != -1) {
goog.bind = goog.bindNative_;
} else {
goog.bind = goog.bindJs_;
}
return goog.bind.apply(null, arguments);
};
/**
* Like bind(), except that a 'this object' is not required. Useful when the
* target function is already bound.
*
* Usage:
* var g = partial(f, arg1, arg2);
* g(arg3, arg4);
*
* @param {Function} fn A function to partially apply.
* @param {...*} var_args Additional arguments that are partially applied to fn.
* @return {!Function} A partially-applied form of the function bind() was
* invoked as a method of.
*/
goog.partial = function(fn, var_args) {
var args = Array.prototype.slice.call(arguments, 1);
return function() {
// Clone the array (with slice()) and append additional arguments
// to the existing arguments.
var newArgs = args.slice();
newArgs.push.apply(newArgs, arguments);
return fn.apply(this, newArgs);
};
};
/**
* Copies all the members of a source object to a target object. This method
* does not work on all browsers for all objects that contain keys such as
* toString or hasOwnProperty. Use goog.object.extend for this purpose.
* @param {Object} target Target.
* @param {Object} source Source.
*/
goog.mixin = function(target, source) {
for (var x in source) {
target[x] = source[x];
}
// For IE7 or lower, the for-in-loop does not contain any properties that are
// not enumerable on the prototype object (for example, isPrototypeOf from
// Object.prototype) but also it will not include 'replace' on objects that
// extend String and change 'replace' (not that it is common for anyone to
// extend anything except Object).
};
/**
* @return {number} An integer value representing the number of milliseconds
* between midnight, January 1, 1970 and the current time.
*/
goog.now = (goog.TRUSTED_SITE && Date.now) || (function() {
// Unary plus operator converts its operand to a number which in the case of
// a date is done by calling getTime().
return +new Date();
});
/**
* Evals JavaScript in the global scope. In IE this uses execScript, other
* browsers use goog.global.eval. If goog.global.eval does not evaluate in the
* global scope (for example, in Safari), appends a script tag instead.
* Throws an exception if neither execScript or eval is defined.
* @param {string} script JavaScript string.
*/
goog.globalEval = function(script) {
if (goog.global.execScript) {
goog.global.execScript(script, 'JavaScript');
} else if (goog.global.eval) {
// Test to see if eval works
if (goog.evalWorksForGlobals_ == null) {
goog.global.eval('var _et_ = 1;');
if (typeof goog.global['_et_'] != 'undefined') {
delete goog.global['_et_'];
goog.evalWorksForGlobals_ = true;
} else {
goog.evalWorksForGlobals_ = false;
}
}
if (goog.evalWorksForGlobals_) {
goog.global.eval(script);
} else {
var doc = goog.global.document;
var scriptElt = doc.createElement('script');
scriptElt.type = 'text/javascript';
scriptElt.defer = false;
// Note(user): can't use .innerHTML since "t('<test>')" will fail and
// .text doesn't work in Safari 2. Therefore we append a text node.
scriptElt.appendChild(doc.createTextNode(script));
doc.body.appendChild(scriptElt);
doc.body.removeChild(scriptElt);
}
} else {
throw Error('goog.globalEval not available');
}
};
/**
* Indicates whether or not we can call 'eval' directly to eval code in the
* global scope. Set to a Boolean by the first call to goog.globalEval (which
* empirically tests whether eval works for globals). @see goog.globalEval
* @type {?boolean}
* @private
*/
goog.evalWorksForGlobals_ = null;
/**
* Optional map of CSS class names to obfuscated names used with
* goog.getCssName().
* @type {Object|undefined}
* @private
* @see goog.setCssNameMapping
*/
goog.cssNameMapping_;
/**
* Optional obfuscation style for CSS class names. Should be set to either
* 'BY_WHOLE' or 'BY_PART' if defined.
* @type {string|undefined}
* @private
* @see goog.setCssNameMapping
*/
goog.cssNameMappingStyle_;
/**
* Handles strings that are intended to be used as CSS class names.
*
* This function works in tandem with @see goog.setCssNameMapping.
*
* Without any mapping set, the arguments are simple joined with a hyphen and
* passed through unaltered.
*
* When there is a mapping, there are two possible styles in which these
* mappings are used. In the BY_PART style, each part (i.e. in between hyphens)
* of the passed in css name is rewritten according to the map. In the BY_WHOLE
* style, the full css name is looked up in the map directly. If a rewrite is
* not specified by the map, the compiler will output a warning.
*
* When the mapping is passed to the compiler, it will replace calls to
* goog.getCssName with the strings from the mapping, e.g.
* var x = goog.getCssName('foo');
* var y = goog.getCssName(this.baseClass, 'active');
* becomes:
* var x= 'foo';
* var y = this.baseClass + '-active';
*
* If one argument is passed it will be processed, if two are passed only the
* modifier will be processed, as it is assumed the first argument was generated
* as a result of calling goog.getCssName.
*
* @param {string} className The class name.
* @param {string=} opt_modifier A modifier to be appended to the class name.
* @return {string} The class name or the concatenation of the class name and
* the modifier.
*/
goog.getCssName = function(className, opt_modifier) {
var getMapping = function(cssName) {
return goog.cssNameMapping_[cssName] || cssName;
};
var renameByParts = function(cssName) {
// Remap all the parts individually.
var parts = cssName.split('-');
var mapped = [];
for (var i = 0; i < parts.length; i++) {
mapped.push(getMapping(parts[i]));
}
return mapped.join('-');
};
var rename;
if (goog.cssNameMapping_) {
rename = goog.cssNameMappingStyle_ == 'BY_WHOLE' ?
getMapping : renameByParts;
} else {
rename = function(a) {
return a;
};
}
if (opt_modifier) {
return className + '-' + rename(opt_modifier);
} else {
return rename(className);
}
};
/**
* Sets the map to check when returning a value from goog.getCssName(). Example:
* <pre>
* goog.setCssNameMapping({
* "goog": "a",
* "disabled": "b",
* });
*
* var x = goog.getCssName('goog');
* // The following evaluates to: "a a-b".
* goog.getCssName('goog') + ' ' + goog.getCssName(x, 'disabled')
* </pre>
* When declared as a map of string literals to string literals, the JSCompiler
* will replace all calls to goog.getCssName() using the supplied map if the
* --closure_pass flag is set.
*
* @param {!Object} mapping A map of strings to strings where keys are possible
* arguments to goog.getCssName() and values are the corresponding values
* that should be returned.
* @param {string=} opt_style The style of css name mapping. There are two valid
* options: 'BY_PART', and 'BY_WHOLE'.
* @see goog.getCssName for a description.
*/
goog.setCssNameMapping = function(mapping, opt_style) {
goog.cssNameMapping_ = mapping;
goog.cssNameMappingStyle_ = opt_style;
};
/**
* To use CSS renaming in compiled mode, one of the input files should have a
* call to goog.setCssNameMapping() with an object literal that the JSCompiler
* can extract and use to replace all calls to goog.getCssName(). In uncompiled
* mode, JavaScript code should be loaded before this base.js file that declares
* a global variable, CLOSURE_CSS_NAME_MAPPING, which is used below. This is
* to ensure that the mapping is loaded before any calls to goog.getCssName()
* are made in uncompiled mode.
*
* A hook for overriding the CSS name mapping.
* @type {Object|undefined}
*/
goog.global.CLOSURE_CSS_NAME_MAPPING;
if (!COMPILED && goog.global.CLOSURE_CSS_NAME_MAPPING) {
// This does not call goog.setCssNameMapping() because the JSCompiler
// requires that goog.setCssNameMapping() be called with an object literal.
goog.cssNameMapping_ = goog.global.CLOSURE_CSS_NAME_MAPPING;
}
/**
* Gets a localized message.
*
* This function is a compiler primitive. If you give the compiler a localized
* message bundle, it will replace the string at compile-time with a localized
* version, and expand goog.getMsg call to a concatenated string.
*
* Messages must be initialized in the form:
* <code>
* var MSG_NAME = goog.getMsg('Hello {$placeholder}', {'placeholder': 'world'});
* </code>
*
* @param {string} str Translatable string, places holders in the form {$foo}.
* @param {Object=} opt_values Map of place holder name to value.
* @return {string} message with placeholders filled.
*/
goog.getMsg = function(str, opt_values) {
if (opt_values) {
str = str.replace(/\{\$([^}]+)}/g, function(match, key) {
return key in opt_values ? opt_values[key] : match;
});
}
return str;
};
/**
* Gets a localized message. If the message does not have a translation, gives a
* fallback message.
*
* This is useful when introducing a new message that has not yet been
* translated into all languages.
*
* This function is a compiler primitive. Must be used in the form:
* <code>var x = goog.getMsgWithFallback(MSG_A, MSG_B);</code>
* where MSG_A and MSG_B were initialized with goog.getMsg.
*
* @param {string} a The preferred message.
* @param {string} b The fallback message.
* @return {string} The best translated message.
*/
goog.getMsgWithFallback = function(a, b) {
return a;
};
/**
* Exposes an unobfuscated global namespace path for the given object.
* Note that fields of the exported object *will* be obfuscated, unless they are
* exported in turn via this function or goog.exportProperty.
*
* Also handy for making public items that are defined in anonymous closures.
*
* ex. goog.exportSymbol('public.path.Foo', Foo);
*
* ex. goog.exportSymbol('public.path.Foo.staticFunction', Foo.staticFunction);
* public.path.Foo.staticFunction();
*
* ex. goog.exportSymbol('public.path.Foo.prototype.myMethod',
* Foo.prototype.myMethod);
* new public.path.Foo().myMethod();
*
* @param {string} publicPath Unobfuscated name to export.
* @param {*} object Object the name should point to.
* @param {Object=} opt_objectToExportTo The object to add the path to; default
* is goog.global.
*/
goog.exportSymbol = function(publicPath, object, opt_objectToExportTo) {
goog.exportPath_(publicPath, object, opt_objectToExportTo);
};
/**
* Exports a property unobfuscated into the object's namespace.
* ex. goog.exportProperty(Foo, 'staticFunction', Foo.staticFunction);
* ex. goog.exportProperty(Foo.prototype, 'myMethod', Foo.prototype.myMethod);
* @param {Object} object Object whose static property is being exported.
* @param {string} publicName Unobfuscated name to export.
* @param {*} symbol Object the name should point to.
*/
goog.exportProperty = function(object, publicName, symbol) {
object[publicName] = symbol;
};
/**
* Inherit the prototype methods from one constructor into another.
*
* Usage:
* <pre>
* function ParentClass(a, b) { }
* ParentClass.prototype.foo = function(a) { };
*
* function ChildClass(a, b, c) {
* ChildClass.base(this, 'constructor', a, b);
* }
* goog.inherits(ChildClass, ParentClass);
*
* var child = new ChildClass('a', 'b', 'see');
* child.foo(); // This works.
* </pre>
*
* @param {Function} childCtor Child class.
* @param {Function} parentCtor Parent class.
*/
goog.inherits = function(childCtor, parentCtor) {
/** @constructor */
function tempCtor() {};
tempCtor.prototype = parentCtor.prototype;
childCtor.superClass_ = parentCtor.prototype;
childCtor.prototype = new tempCtor();
/** @override */
childCtor.prototype.constructor = childCtor;
/**
* Calls superclass constructor/method.
*
* This function is only available if you use goog.inherits to
* express inheritance relationships between classes.
*
* NOTE: This is a replacement for goog.base and for superClass_
* property defined in childCtor.
*
* @param {!Object} me Should always be "this".
* @param {string} methodName The method name to call. Calling
* superclass constructor can be done with the special string
* 'constructor'.
* @param {...*} var_args The arguments to pass to superclass
* method/constructor.
* @return {*} The return value of the superclass method/constructor.
*/
childCtor.base = function(me, methodName, var_args) {
var args = Array.prototype.slice.call(arguments, 2);
return parentCtor.prototype[methodName].apply(me, args);
};
};
/**
* Call up to the superclass.
*
* If this is called from a constructor, then this calls the superclass
* constructor with arguments 1-N.
*
* If this is called from a prototype method, then you must pass the name of the
* method as the second argument to this function. If you do not, you will get a
* runtime error. This calls the superclass' method with arguments 2-N.
*
* This function only works if you use goog.inherits to express inheritance
* relationships between your classes.
*
* This function is a compiler primitive. At compile-time, the compiler will do
* macro expansion to remove a lot of the extra overhead that this function
* introduces. The compiler will also enforce a lot of the assumptions that this
* function makes, and treat it as a compiler error if you break them.
*
* @param {!Object} me Should always be "this".
* @param {*=} opt_methodName The method name if calling a super method.
* @param {...*} var_args The rest of the arguments.
* @return {*} The return value of the superclass method.
* @suppress {es5Strict} This method can not be used in strict mode, but
* all Closure Library consumers must depend on this file.
*/
goog.base = function(me, opt_methodName, var_args) {
var caller = arguments.callee.caller;
if (goog.STRICT_MODE_COMPATIBLE || (goog.DEBUG && !caller)) {
throw Error('arguments.caller not defined. goog.base() cannot be used ' +
'with strict mode code. See ' +
'http://www.ecma-international.org/ecma-262/5.1/#sec-C');
}
if (caller.superClass_) {
// This is a constructor. Call the superclass constructor.
return caller.superClass_.constructor.apply(
me, Array.prototype.slice.call(arguments, 1));
}
var args = Array.prototype.slice.call(arguments, 2);
var foundCaller = false;
for (var ctor = me.constructor;
ctor; ctor = ctor.superClass_ && ctor.superClass_.constructor) {
if (ctor.prototype[opt_methodName] === caller) {
foundCaller = true;
} else if (foundCaller) {
return ctor.prototype[opt_methodName].apply(me, args);
}
}
// If we did not find the caller in the prototype chain, then one of two
// things happened:
// 1) The caller is an instance method.
// 2) This method was not called by the right caller.
if (me[opt_methodName] === caller) {
return me.constructor.prototype[opt_methodName].apply(me, args);
} else {
throw Error(
'goog.base called from a method of one name ' +
'to a method of a different name');
}
};
/**
* Allow for aliasing within scope functions. This function exists for
* uncompiled code - in compiled code the calls will be inlined and the aliases
* applied. In uncompiled code the function is simply run since the aliases as
* written are valid JavaScript.
*
*
* @param {function()} fn Function to call. This function can contain aliases
* to namespaces (e.g. "var dom = goog.dom") or classes
* (e.g. "var Timer = goog.Timer").
*/
goog.scope = function(fn) {
fn.call(goog.global);
};
/*
* To support uncompiled, strict mode bundles that use eval to divide source
* like so:
* eval('someSource;//# sourceUrl sourcefile.js');
* We need to export the globally defined symbols "goog" and "COMPILED".
* Exporting "goog" breaks the compiler optimizations, so we required that
* be defined externally.
* NOTE: We don't use goog.exportSymbol here because we don't want to trigger
* extern generation when that compiler option is enabled.
*/
if (!COMPILED) {
goog.global['COMPILED'] = COMPILED;
}
//==============================================================================
// goog.defineClass implementation
//==============================================================================
/**
* Creates a restricted form of a Closure "class":
* - from the compiler's perspective, the instance returned from the
* constructor is sealed (no new properties may be added). This enables
* better checks.
* - the compiler will rewrite this definition to a form that is optimal
* for type checking and optimization (initially this will be a more
* traditional form).
*
* @param {Function} superClass The superclass, Object or null.
* @param {goog.defineClass.ClassDescriptor} def
* An object literal describing the
* the class. It may have the following properties:
* "constructor": the constructor function
* "statics": an object literal containing methods to add to the constructor
* as "static" methods or a function that will receive the constructor
* function as its only parameter to which static properties can
* be added.
* all other properties are added to the prototype.
* @return {!Function} The class constructor.
*/
goog.defineClass = function(superClass, def) {
// TODO(johnlenz): consider making the superClass an optional parameter.
var constructor = def.constructor;
var statics = def.statics;
// Wrap the constructor prior to setting up the prototype and static methods.
if (!constructor || constructor == Object.prototype.constructor) {
constructor = function() {
throw Error('cannot instantiate an interface (no constructor defined).');
};
}
var cls = goog.defineClass.createSealingConstructor_(constructor, superClass);
if (superClass) {
goog.inherits(cls, superClass);
}
// Remove all the properties that should not be copied to the prototype.
delete def.constructor;
delete def.statics;
goog.defineClass.applyProperties_(cls.prototype, def);
if (statics != null) {
if (statics instanceof Function) {
statics(cls);
} else {
goog.defineClass.applyProperties_(cls, statics);
}
}
return cls;
};
/**
* @typedef {
* !Object|
* {constructor:!Function}|
* {constructor:!Function, statics:(Object|function(Function):void)}}
*/
goog.defineClass.ClassDescriptor;
/**
* @define {boolean} Whether the instances returned by
* goog.defineClass should be sealed when possible.
*/
goog.define('goog.defineClass.SEAL_CLASS_INSTANCES', goog.DEBUG);
/**
* If goog.defineClass.SEAL_CLASS_INSTANCES is enabled and Object.seal is
* defined, this function will wrap the constructor in a function that seals the
* results of the provided constructor function.
*
* @param {!Function} ctr The constructor whose results maybe be sealed.
* @param {Function} superClass The superclass constructor.
* @return {!Function} The replacement constructor.
* @private
*/
goog.defineClass.createSealingConstructor_ = function(ctr, superClass) {
if (goog.defineClass.SEAL_CLASS_INSTANCES &&
Object.seal instanceof Function) {
// Don't seal subclasses of unsealable-tagged legacy classes.
if (superClass && superClass.prototype &&
superClass.prototype[goog.UNSEALABLE_CONSTRUCTOR_PROPERTY_]) {
return ctr;
}
/** @this {*} */
var wrappedCtr = function() {
// Don't seal an instance of a subclass when it calls the constructor of
// its super class as there is most likely still setup to do.
var instance = ctr.apply(this, arguments) || this;
if (this.constructor === wrappedCtr) {
Object.seal(instance);
}
return instance;
};
return wrappedCtr;
}
return ctr;
};
// TODO(johnlenz): share these values with the goog.object
/**
* The names of the fields that are defined on Object.prototype.
* @type {!Array.<string>}
* @private
* @const
*/
goog.defineClass.OBJECT_PROTOTYPE_FIELDS_ = [
'constructor',
'hasOwnProperty',
'isPrototypeOf',
'propertyIsEnumerable',
'toLocaleString',
'toString',
'valueOf'
];
// TODO(johnlenz): share this function with the goog.object
/**
* @param {!Object} target The object to add properties to.
* @param {!Object} source The object to copy properites from.
* @private
*/
goog.defineClass.applyProperties_ = function(target, source) {
// TODO(johnlenz): update this to support ES5 getters/setters
var key;
for (key in source) {
if (Object.prototype.hasOwnProperty.call(source, key)) {
target[key] = source[key];
}
}
// For IE the for-in-loop does not contain any properties that are not
// enumerable on the prototype object (for example isPrototypeOf from
// Object.prototype) and it will also not include 'replace' on objects that
// extend String and change 'replace' (not that it is common for anyone to
// extend anything except Object).
for (var i = 0; i < goog.defineClass.OBJECT_PROTOTYPE_FIELDS_.length; i++) {
key = goog.defineClass.OBJECT_PROTOTYPE_FIELDS_[i];
if (Object.prototype.hasOwnProperty.call(source, key)) {
target[key] = source[key];
}
}
};
/**
* Sealing classes breaks the older idiom of assigning properties on the
* prototype rather than in the constructor. As such, goog.defineClass
* must not seal subclasses of these old-style classes until they are fixed.
* Until then, this marks a class as "broken", instructing defineClass
* not to seal subclasses.
* @param {!Function} ctr The legacy constructor to tag as unsealable.
*/
goog.tagUnsealableClass = function(ctr) {
if (!COMPILED && goog.defineClass.SEAL_CLASS_INSTANCES) {
ctr.prototype[goog.UNSEALABLE_CONSTRUCTOR_PROPERTY_] = true;
}
};
/**
* Name for unsealable tag property.
* @const @private {string}
*/
goog.UNSEALABLE_CONSTRUCTOR_PROPERTY_ = 'goog_defineClass_legacy_unsealable';
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