Check if a local file exists (HTML5 FS API)

Question

I am developing a Chrome extension and I want to check if a file exists. I don't want to do anything with the file: I only want to check its existence.

If I use a XMLHttpRequest it doesn't work, because it is not allowed for security reasons. So I have to use the HTML5 FS API. The problem is that this API has no method to check if a file exists.

I have a variable called "fileExists", and I would want to know how to change its value from false to true or from true to false depending on the existence of a file (determined by a URL).

Thanks.

Answer 1

use something like:

   function exists(fileName, callback) {
        storageRootEntry.getFile(fileName, {create : false}, function() {
            callback(true);
        }, function() {
            callback(false);
        });
    }

where storageRootEntry is correctly initialized root directory. The function will returns "true" if file exists and "false" otherwise. The key point here is second parameter {create : false}