google-closure-library
Version:
Google's common JavaScript library
75 lines (60 loc) • 1.95 kB
JavaScript
/**
* @license
* Copyright The Closure Library Authors.
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @fileoverview Detection of JScript version.
*/
goog.provide('goog.userAgent.jscript');
goog.require('goog.string');
/**
* @define {boolean} True if it is known at compile time that the runtime
* environment will not be using JScript.
*/
goog.userAgent.jscript.ASSUME_NO_JSCRIPT =
goog.define('goog.userAgent.jscript.ASSUME_NO_JSCRIPT', false);
/**
* Whether we detect that the user agent is using Microsoft JScript.
* @type {boolean}
*/
goog.userAgent.jscript.HAS_JSCRIPT = false;
/**
* The installed version of JScript.
* @type {string}
*/
goog.userAgent.jscript.VERSION = '0';
/**
* Initializer for goog.userAgent.jscript. Detects if the user agent is using
* Microsoft JScript and which version of it.
*
* This is a named function so that it can be stripped via the jscompiler
* option for stripping types.
* @package
*/
goog.userAgent.jscript.init = function() {
'use strict';
var hasScriptEngine = 'ScriptEngine' in goog.global;
goog.userAgent.jscript.HAS_JSCRIPT =
hasScriptEngine && goog.global['ScriptEngine']() == 'JScript';
if (goog.userAgent.jscript.HAS_JSCRIPT) {
goog.userAgent.jscript.VERSION = goog.global['ScriptEngineMajorVersion']() +
'.' + goog.global['ScriptEngineMinorVersion']() + '.' +
goog.global['ScriptEngineBuildVersion']();
}
};
if (!goog.userAgent.jscript.ASSUME_NO_JSCRIPT) {
goog.userAgent.jscript.init();
}
/**
* Whether the installed version of JScript is as new or newer than a given
* version.
* @param {string} version The version to check.
* @return {boolean} Whether the installed version of JScript is as new or
* newer than the given version.
*/
goog.userAgent.jscript.isVersion = function(version) {
'use strict';
return goog.string.compareVersions(goog.userAgent.jscript.VERSION, version) >=
0;
};