RPC

Yesterday I wrote about XMLHttpRequest, and how we can use it to pull XML data from our servers dynamically into our pages without refreshing. The flip side to this is pushing content to the server. To do this we need remote scripting.

Apple once again has set up an informative page on the subject, detailing how to use iframes to accomplish this. Lately, people have come to coin this “new” technology (it’s not exactly new, the method for doing this has been around for years) as AJAX, or Asyncronous Javascript and XML. Interesting buzzword, but the entire idea of this is not limited to Javascript or XML. As Apple elequently says, the method here is called (and has been called for a long time now) RPC, or Remote Procedure Call, which is a general term used to describe the exchange of data between remote computer systems.

RPC can be done with Flash, or the like-named XML-RPC. In fact, we are using one facet of this on our Calendar, pulling dynamic data into Flash movies. Another way of accomplishing this is through iframes with Javascript. It’s nothing new, I remeber doing this with regular framesets circa ’98 or so. The difference for us now is that iframes are standard in browsers, you can get and parse XML with XMLHttpRequest, and some browsers (Mozilla, IE, etc) even have XSLT processors built into them to help with translations and to cut down on server load. Basically the technology has finally caught up to what we want to do with it.

It’s a very interesting technology that I look forward to working with. The best part about it is that it takes existing features and standards and uses them in a new and exciting way. We know Javascript and XML aren’t going away, and we know this has been built into every browser for the last several years. It’s something we can build on and feel confident about doing.