Create Multi-Mobile Applications with PHP

What is a Multi-Mobile Application?

The typical job description in the technology industry doesn’t include hazardous duty pay for all of the annoying acronyms, buzzwords and overhyped slogans that get tossed around. As such, I’m always cautious about using a new one (yes, I still feel a little funny talking about AJAX). However, I have noticed a trend toward a new type of web application that is focused on the delivery of content and interactivity to end users through multiple devices (desktop browser, cell phone, traditional phone, PDA, IM client, etc.). This new breed of application, in my humble opinion, deserves its own buzzword — “Multi-mobile” applications.

Fans of XHTML+Voice and SALT will know instantly what multimodal applications are — applications that support different kinds of user input (i.e., voice, keypad, stylus) through the same interface. Multi-mobile applications are differnet. These applications deliver content that is specifically tailored to the device being employed by the end user. This content is formatted differently based on the requirements of each specific device, and the mode of input is restricted to that supported by the device. Users accessing a form requiring specific input will see different manifestations of the same interface depending on the device they are using. What makes these applications special is that a single code base provides the functionality for device independence. So, whether an end user is making a phone call, using a WAP-enabled browser or an XHTML-enabled PDA the application is built to format an interface appropriately for each device.

I think this is a pretty cool concept, one worthy of its own buzzword. Besides, describing this approach to application design literally — “parallel mono-modality” — doesn’t do it justice in my opinion (needs more zing!).

Building Multi-Mobile Applications

One of the most convenient and powerful ways for building multi-mobile applications that I have come across is a PHP class library called HAWHAW (HTML and WML Hybrid Adapted Webserver). The HAWHAW toolkit actually has two additional elements — HAWHAW XML (an XML-based markup language for creating mobile applications) and HAWXY (a proxy server written in PHP for precessing HAWHAW XML).

The HAWHAW class library comes with an excellent tutorial and a very detailed set of documentation.
As powerful and as useful as this tool is, it does have its limitations. Most are inherent in the nature of developing interfaces for multiple end user devices. Because this tool needs to generate markup for a large number of user agents, many of which have character and space limitations (the HAWHAW documentation notes that “a lot of older WAP devices can not handle more than about 1,400 bytes of compiled data.“) it pays to keep the interface simple.