How to choose between `window.URL.createObjectURL()` and `window.webkitURL.createObjectURL()` based on browser

Question

From the Firefox developer website, I know that Firefox uses

objectURL = window.URL.createObjectURL(file);

to get url of file type, but in

Answer 1

You could define a wrapper function:

function createObjectURL ( file ) {
    if ( window.webkitURL ) {
        return window.webkitURL.createObjectURL( file );
    } else if ( window.URL && window.URL.createObjectURL ) {
        return window.URL.createObjectURL( file );
    } else {
        return null;
    }
}

And then:

// works cross-browser
var url = createObjectURL( file );