FB.Canvas.getPageInfo

Returns a Javascript object containing information about your app's canvas page. You need to provide a callback with the API, where we fetch the new value and return it.

Since a Canvas app runs in an iframe it does not have access to window.innerHeight and window.innerWidth. This method exists to provide access to the client (browser) dimensions as well as the current scroll position and offset coordinates.

Examples

FB.Canvas.getPageInfo(
    function(info) {
        alert('Width: ' + info.clientWidth + ' Height: ' + info.clientHeight);
    }
);