Skip to content

Instantly share code, notes, and snippets.

@tsaniel

tsaniel/LICENSE.txt

Forked from 140bytes/LICENSE.txt
Created October 5, 2011 10:05
Show Gist options
  • Star 1 You must be signed in to star a gist
  • Fork 0 You must be signed in to fork a gist
  • Save tsaniel/1264086 to your computer and use it in GitHub Desktop.
Save tsaniel/1264086 to your computer and use it in GitHub Desktop.
Download ZIP
isWindow
Raw
README.md
Raw
annotated.js
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
}
Raw
index.js
(function(a,b){return!!a&&/[wl]]/.test({}.toString.call(a))||a==(b=a.document)&&b!=a})
Raw
LICENSE.txt
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.
Raw
package.json
{
"name": "isWindow",
"description": "Check if the input is window.",
"keywords": [
"window",
"isWindow",
"DOM",
"jQUery"
]
}
Raw
test.html
<!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>
@tsaniel
Copy link
Author

tsaniel commented Dec 3, 2011

@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