The drag-and-drop functions provided by various JavaScript libraries (jQuery, YUI, etc.) won't work in the iPhone/iPod Touch Safari web browser because the dragging gesture is used for scrolling around the web page. That's a big problem for those of us who use drag-and-drop in our web applications to allow our users to reorder the items in a list, but I've come up with an alternative method for rearranging items using the jQuery JavaScript library that works on the iPhone/iPod browser as well as regular browsers.

I used to change the styles of HTML elements by changing the CSS class or classes associated with the element because changing individual style settings was a pain with regular JavaScript. But the jQuery JavaScript library has a function that makes changing styles easy.

I recently finished a small project that involved optimizing some simple web applications for use on an iPhone/iPod Touch. I won't bore you with the specifics of the project (unless someone asks) but here are some things I learned during the process regarding page design/page behaviors.

A reader asked me if it was possible to sort/rearrange items in nested lists (lists within a main list) using the jQuery UI Sortables code. I told him that it was, and I had actually created a tool for a client recently that made use of that feature. He wanted to know more about how to do it, so I went ahead and created a downloadable working demo of how to do it.

Some of the processes you find in web applications are fairly standard. Most folks can fill out a contact form, or fill out a survey, or make a calendar entry without the need for too much explanation. But what do you do when the form involves business rules that the user may or may not know, or presents the user with a number of options? Here are some techniques I use to provide extra guidance when it's needed.

I wanted to spice up the conference promotional badges on my blog with timers that counted down the days, hours, minutes and seconds until each conference began. Here's how I programmed the timer.

This is a technique I developed recently that allows me to write a single set of server-side code to validate data submitted via an HTML form that can then be executed via AJAX if the user's browser has JavaScript enabled or executed server-side via a regular form post if JavaScript has been disabled. It makes use of the jQuery JavaScript library and a particular jQuery plug-in to make it easy to write the JavaScript functions involved. My example uses ColdFusion as the server-side language, but it could just as easily have been PHP or something else.

You can use this tool in a web application to let users manually rearrange the order in which records or items should be displayed. The new order of the items can be saved either via AJAX or via a form submission. A working example of the tool is included on the page.