A common problem with input forms is that users get impatient and click the submit button twice. This can lead to double (or triple, or quadruple!) form submissions, which can really mess things up (especially if you’ve added a billing step to your form!) Stopping it can be surprisingly complex, but here’s a simple piece of browser script that will prevent most users from making multiple submissions with Gravity Forms. Continue reading
Customisation of web software sometimes requires that you get it to pass around some additional information whenever it makes a page request. Often, putting that information into a cookie isn’t appropriate, so you try to squeeze it into the page query parameters, or form post data through hidden fields. But what if the software makes AJAX requests from jQuery? Luckily, jQuery can help you intercept AJAX requests so that you can customise them too. Continue reading
If you build fragments of HTML and JavaScript dynamically from browser script, you need to take care to encode any special characters in your strings. Building your HTML using DOM createElement() and createTextNode() is often better, but sometimes the better solution is to generate a block of HTML. Here’s a couple of simple functions to do that, quickly. Continue reading
The Opera browser persistently refuses to honour “return false” in an onclick handler, and is quite possibly the only web browser that does this. Because I don’t usually add event handlers inline any more, I haven’t noticed this defect until now, but it just bit me today. Continue reading
I just went searching for a nice, simple example of populating a form from a database, using AJAX and JSON. I hope it’s just that my Google juice is depleted after a hard week, but I couldn’t easily find one. So I wrote one. Continue reading
I just stared in horror wonder at the wp-e-commerce script that handles cart updates. Wow. Just… wow. Forget any thought of nicely hooking into that to add some extra client-side actions, it’s a mess and looks like it will probably get worse before it gets better. But fortunately, there is another way. Continue reading
CSS drop-down menus are very popular on sites with a hierarchy of pages. They let you get to where you want to go without having to navigate the pages in that hierarchy. But pure-CSS menus suffer a problem: touch devices often can’t show the drop-down, because they don’t have “hover” and clicking on the top level link goes there. This snippet offers a way around that. Continue reading
Apparently, Internet Explorer 7 is stupid. I mean, it lets you create a form input element dynamically, and add it to a form, but the form doesn’t know it by name. And I only just found this out! Continue reading
Pretty much all web developers should know by now that browser sniffing is evil. If you don’t know why, you should definitely read Richard Cornford’s excellent treatise Browser Detection (and What to Do Instead). Feature detection, where you look for the specific feature you want to use, is much safer; taken to the extreme, it can end up like the rather clever Modernizr project. But what if you really do just want to know if your code has the misfortune to be running on IE7? Continue reading
I love CSS3PIE. I love that I can make use of some of the CSS3 niceties like rounded corners and box shadow, and even IE7 and IE8 can keep up with the more modern browsers and not look too shabby. But if you’re adding or moving elements around on your page dynamically, e.g. changing something from display:block to display:none and back, sometimes PIE can’t keep up and leaves a box shadow in a strange place. Continue reading