Window Resize in JS

I will write a full article on responsive website design & JavaScript soon, but for now here’s a quick snippet! (With a little help from jQuery, naturally.)

var resizeTimeout, win = $(window);
win.bind('resize', function()
    if (resizeTimeout) clearTimeout(resizeTimeout);
    resizeTimeout = setTimeout(function()
        var width = win.width();
        /* do responsive stuff... */
    }, 100);

The basic idea is that you don’t want to be hammering the window resize event because it gets fired repeatedly when a user manually resizes their browser. Instead you should use a short timeout to wait for resizing to end.

You may ask, why am I using JavaScript at all, surely pure CSS media queries are better? For most circumstances they are, but when you’re applying interactivity to a website, that experience can differ greatly depending on the screen size. My latest build involves a lot of Google Maps work but only for larger screens (an alternate — and default before JS kicks in — content design is presented to suit smaller screens). Loading in the whole Google Maps JavaScript library ignorant of usage is a heavy burden on bandwidth.

I’m using this technique to load JavaScript and other content like high-res images very late in the game. If the window never reaches the larger breakpoints no unused resources are ever wasted.

More soon!

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