Efficient callback management for window.onresize

watchResize.js

(function( window ){
    window.watchResize = function( callback ){
        var resizing;
        callback.size = 0;
        function done()
        {
            var curr_size = window.innerWidth;
            clearTimeout( resizing );
            resizing = null;
            // only run on a true resize
            if ( callback.size != curr_size )
            {
                callback();
                callback.size = curr_size;
            }
        }
        window.addEventListener('resize', function(){
            if ( resizing )
            {
                clearTimeout( resizing );
                resizing = null;
            }
            resizing = setTimeout( done, 50 );
        });
        // init
        callback();
    };
}(window));

watchResize.min.js

(function(a){a.watchResize=function(d){var c;d.size=0;function b(){var e=a.innerWidth;clearTimeout(c);c=null;if(d.size!=e){d();d.size=e}}a.addEventListener("resize",function(){if(c){clearTimeout(c);c=null}c=setTimeout(b,50)});d()}}(window));