Check whether user has a Chrome extension installed

Question

I am in the process of building a Chrome extension, and for the whole thing to work the way I would like it to, I need an external JavaScript script to be able to detect if

Answer 1

If you have control over the Chrome extension, you can try what I did:

// Inside Chrome extension
var div = document.createElement('div');
div.setAttribute('id', 'myapp-extension-installed-div');
document.getElementsByTagName('body')[0].appendChild(div);

And then:

// On web page that needs to detect extension
if ($('#myapp-extension-installed-div').length) {

}

It feels a little hacky, but I couldn't get the other methods to work, and I worry about Chrome changing its API here. It's doubtful this method will stop working any time soon.