JavaScript file_exists

Returns true if filename exists

function file_exists (url) {
    // Returns true if filename exists  
    // 
    // version: 909.322
    // discuss at: http://phpjs.org/functions/file_exists    // +   original by: Enrique Gonzalez
    // +      input by: Jani Hartikainen
    // +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // %        note 1: This function uses XmlHttpRequest and cannot retrieve resource from different domain.
    // %        note 1: Synchronous so may lock up browser, mainly here for study purposes.     // *     example 1: file_exists('http://kevin.vanzonneveld.net/pj_test_supportfile_1.htm');
    // *     returns 1: '123'
    
    var req = this.window.ActiveXObject ? new ActiveXObject("Microsoft.XMLHTTP") : new XMLHttpRequest();
    if (!req) {throw new Error('XMLHttpRequest not supported');}      
    // HEAD Results are usually shorter (faster) than GET
    req.open('HEAD', url, false);
    req.send(null);
    if (req.status == 200){        return true;
    }
    
    return false;
}

external links: original PHP docs | raw js source

Examples

Running

1	file_exists('http://kevin.vanzonneveld.net/pj_test_supportfile_1.htm');

Should return

'123'

Dependencies

No dependencies, you can use this function standalone.

Open syntax issues

php.js uses JsLint to help us keep our code consistent and prevent some common bugs.

Eventually we want all code to pass or at least take into consideration most fixes suggested by JsLint, following this JsLint configuration we’ve decided on.

Authors

Thanks to the following developers, you get to have file_exists goodness in JavaScript.

Enrique Gonzalez ( original )
Jani Hartikainen ( input )
Kevin van Zonneveld ( improved )

Comments

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Use:

[CODE]
your_stuff('here');
[/CODE]

for proper code formatting
By submitting code here you are allowing us to use it in php.js hence dual licensing it under the MIT and GPL licenses

Kevin van Zonneveld
18 Nov '08

@ frame: This could happen if you are writing multiple comments at the same time, cause only one allowed security key is remembered per user. Could this be your case as well?

frame
18 Nov '08

Do you have updated the link? I downloaded the lib some time before and the function was not included.. now it is o.O

Another Bug?: The security code i typed in was not valid.. for 3 times.. and also did not reload to another code.. always the same..

Kevin van Zonneveld
14 Nov '08

@ frame: But it is, what link are you using?

frame
14 Nov '08

The function file_exists isn't avaiable in php.js.

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JavaScript file_exists

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