iphone/ipad triggering unexpected resize events
I'm working on a mobile version of my site. I'm using media queries and CSS as much as possible, but I'm also using some javascript to, for example, turn my navigation into a collapse/expand list on smaller devices to save room.
To handle all of this, I was attempting to use the window.resize event. This allows the magic to happen on desktop browsers while they're resized, but I'm getting resize events on iPad/iPhone when I'm not expecting them.
On desktop browsers, I only get a resize event if I actually resize the window. On mobile browsers I get the resize event when I change orientation (expected), but I also get it when I toggle to expand/collapse something.
Here's a simple example:
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>
<title>Resize test</title>
<style>
.box {height: 10000px; background: green; display: none;}
</style>
<script>
$(function(){
$(".opener").click(function(){
$(".box").slideToggle();
});
$(window).resize(function(){
alert("resized");
});
});
</script>
</head>
<body>
<a href="#" class="opener">Open/close me</a>
<div class="box"></div>
</body>
</html>
When you click the link on a desktop browser, no alert. Click the link on iPhone/iPad, you get the alert. What's the deal?
Answer
Store the window width and check that it has actually changed before proceeding with your $(window).resize function:
jQuery(document).ready(function($) {
// Store the window width
var windowWidth = $(window).width();
// Resize Event
$(window).resize(function(){
// Check window width has actually changed and it's not just iOS triggering a resize event on scroll
if ($(window).width() != windowWidth) {
// Update the window width for next time
windowWidth = $(window).width();
// Do stuff here
}
// Otherwise do nothing
});
});