Page caching and the HTML5 onPageShow window event

Just last week I was confronted with a problem that occurred only in Firefox. This is rare, since Firefox is very good at implementing HTML/CSS/JavaScript standards. Basically what I had was a report criteria page being displayed to a user and then once he hit the submit button, we pop-up a JavaScript overlay saying "Processing...". Thing is, if the user hits the browser's "Back" button (yes that horrible button), the overlay was remaining, even thought in the window onLoad event we were telling the overlay to unload itself.

I believe the problem starting with a recent version of Firefox where the browser implemented page caching. Subsequently, when the "Back" button is hit, the page is loaded from the cache and the onLoad event is not fired again. So our code to unload the overlay was not being executed.

The solution as I found it, is that in this scenario, Firefox is firing the onPageShow event, giving us a chance to do our clean up work. So we basically added the following line of code in the window onLoad event handler:

$(window).bind( "pageshow", function() { $.unblockUI(); } ); 

We still left the old code there so that it works for other browsers and older versions of Firefox.

More info on Adobe Shadow

In my last post I spoke about Adobe Shadow, their new tool for test web applications on various mobile devices concurrently. Since then, Adobe has posted a couple of short videos displaying the capabilities of Adobe Shadow. So what are you waiting for, click on the links below to check them out!

• Shadow Intro
• Remote Inspection

Adobe releases Shadow beta

In this mobile crazy world we work and live in today, as web application developers one of the hardest things to do is testing. With all the various devices and all the various screen sizes, testing your web application to make sure it looks and works properly in various permutations can be a difficult thing.

Enter Adobe Shadow, an inspection and preview tool. Here is how it works. You link a device (phone, tablet) to your main computer and then as you browse your web site on your main computer, the same web site automatically appears on your linked device(s). Furthermore you can remotely inspect the DOM and CSS from the web browser of the device, make on-the-fly changes and see them take effect in real-time. This is a great way to do testing across different devices and get your web application just right. Check out the quick tutorial video to learn more!