Just like the jQuery's one http://api.jquery.com/jQuery.isWindow/. But more relible.
-
-
Save tsaniel/1264086 to your computer and use it in GitHub Desktop.
isWindow
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| function( | |
| a, // input | |
| b // placeholder for property document of a | |
| ){ | |
| return | |
| // cannot be falsy value, mainly to prevent null and undefined (regarded as global object in some browsers) | |
| !!a && | |
| // checking types with Object.prototype.toString.call is always a good way | |
| // however, for window, is a bit difficult | |
| // let's see the results in different browsers (except IE678, which return "[object Object]") | |
| // "[object Window]" | |
| // "[object DOMWindow]" | |
| // "[object global]" | |
| // so, we can simply check if the input's [[Class]] is ended with w] or l] | |
| /[wl]]/.test({}.toString.call(a)) || | |
| // believe me, IE is not a good guy | |
| // why? | |
| // because in which, window == document but document != window | |
| // what a wtf feature! | |
| a == (b=a.document) && b != a | |
| } |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| (function(a,b){return!!a&&/[wl]]/.test({}.toString.call(a))||a==(b=a.document)&&b!=a}) |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE | |
| Version 2, December 2004 | |
| Copyright (C) 2011 YOUR_NAME_HERE <YOUR_URL_HERE> | |
| Everyone is permitted to copy and distribute verbatim or modified | |
| copies of this license document, and changing it is allowed as long | |
| as the name is changed. | |
| DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE | |
| TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION | |
| 0. You just DO WHAT THE FUCK YOU WANT TO. |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| { | |
| "name": "isWindow", | |
| "description": "Check if the input is window.", | |
| "keywords": [ | |
| "window", | |
| "isWindow", | |
| "DOM", | |
| "jQUery" | |
| ] | |
| } |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| <!DOCTYPE html> | |
| <title>Foo</title> | |
| <div>Expected value: <b>true</b></div> | |
| <div>Actual value: <b id="ret"></b></div> | |
| <script> | |
| // write a small example that shows off the API for your example | |
| // and tests it in one fell swoop. | |
| var myFunction = (function(a,b){return!!a&&/[wl]]/.test({}.toString.call(a))||a==(b=a.document)&&b!=a}) | |
| document.getElementById( "ret" ).innerHTML = myFunction(window) | |
| </script> |
Not in Chrome 14.
this.constructor !== window
Damn, there it's DOMWindow... /Wi/.test(a.constructor), maybe?
{constructor:'Wi'}
Let's try this:
function(a,b){b=this.Window||this.DOMWindow;return!!a&&b?a instanceof b:a==(b=a.document)&&b!=a}
It is sad that it won't work with iframes...
Rewritten to probably work with (i)frames:
function(a,b){return!!a&&(b=a.Window||a.DOMWindow)?a instanceof b:a==(b=a.document)&&b!=a}
It cannot work with my chromium 12...
Alas, it's not exposed in Chrome. OK, let's try this:
function(a,b){return!!a&&(b=top.constructor)?a instanceof b:a==(b=a.document)&&b!=a}
It won't work with (i)frame as well, because the scope of top differs from (i)frame.
Right. Any idea how to get DOMWindow in Chrome if its not exposed?
The magic __proto__?
Doesn't help very much, because it is different between frames.
I think it is hard. In fact, the original code is enough.
Try this:
function(a,b){return a&&a==a[b='window']&&a==a[b][b]}
Clever. Exploiting the fact that any global object is exposed as a property of window, and window itself is a global object.
@phoetry: It's clever but it won't work.
var a = {};
a.window = a;
(function(a,b){return a&&a==a[b='window']&&a==a[b][b]})(a) // true
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
That's true. How about
(a||0).constructor===this.Window? Works in all modern browsers (not in IE 7 or older).