Got network error to check if a file exists

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I got Network error to check if a file exists using the piece of code (sourced from )[^]below:

function UrlExists(url) {   // where url = 'http://xxxxx/fileName.png'  
    var http = new XMLHttpRequest();
    http.open('HEAD', url, false);
    http.send();
    return http.status != 404;
}

How to debug this Network error?
I also tried an alternative approach as shown below:

JavaScript

var fso = new ActiveXObject("Scripting.FileSystemObject");
fileBool = fso.FileExists("\\myNetworkFolder\myFile.png");

But the objective can' be created even though I use IE as the browser. How can the ActiveXObject be used?
Thanks if you can help.

What I have tried:

Got Network error to check if a file exists

Posted 28-Apr-16 9:29am

s yu

Updated 29-Apr-16 2:27am

v3

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ZurdoDev 28-Apr-16 16:21pm

1. What is the exact error?
2. No, ActiveX only runs in IE.

Sergey Alexandrovich Kryukov 28-Apr-16 20:22pm

This "alternative approach" with ActiveX is enough reason for a security-savvy users to black-list such site or Web application. :-)
—SA

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Sergey Alexandrovich Kryukov · Answer 1 · 2016-04-28T14:24:00

This name, "\\myNetworkFolder\myFile.png", is not generally accessible from the Web application. This is the UNC path name which might be accessible, in particular, through the Windows sharing service executed by other hosts of the same LAN:
Path (computing) — Wikipedia, the free encyclopedia[^].

But the server-side code is executed in the sandboxed environment which only allows access to the file system objects under the root directory set up for your site. This is done for serious security reasons.

If you really want to store images on a separate hosts, there are some (potentially heavier) alternatives. First of all, please see:
Connecting Web Sites to UNC Network Shares[^].

Also, you can serve-up those images on another host through as standard FTP server or another HTTP server. The you can access the data by your Web application's server-side code:
FtpWebRequest Class (System.Net)[^],
HttpWebRequest Class (System.Net)[^],
WebRequest Class (System.Net)[^].

But first of all, I would think about moving all these images to the location of your Web site. Why not keeping it simple?

—SA