javascript - Detect if browser supports data uri scheme with iframes

Question

Internet Explorer does not support the data uri scheme for iframe urls (see http://msdn.microsoft.com/en-us/library/cc848897%28v=vs.85%29.aspx). Other browsers do. As browser detection is loaded with testing and future-proofing problems, I want to use feature detection to work around this issue.

So: how can I detect whether or not a browser supports the data uri scheme for iframes?

Answer 1

This solution by Kevin Martin is tested and seems to be giving the correct result in IE, FF and Chrome:

function iframeDataURITest(src) {
    var support,
        iframe = document.createElement('iframe');

    iframe.style.display = 'none';
    iframe.setAttribute('src', src);

    document.body.appendChild(iframe);

    try {
        support = !!iframe.contentDocument;
    } catch (e) {
        support = false;
    }

    document.body.removeChild(iframe);

    return support;
}

console.log('Empty data uri', iframeDataURITest('data:;base64,'));
console.log('"*" data uri', iframeDataURITest('data:text/html;base64,Kg=='));

Unlike some of the other suggestions, it is synchronous - no need to mess around with timeouts or callbacks.