In yesterday's post I talked a little bit about some of the details on how I used messaging to connect a front end on demand request to a back end scheduled data processing mechanism. In this post we're going to talk about how to send data from a web page to a running Flex application without using HTTP. It is really quite easy.

His demo application watches a Magento instance and notifies him whenever a new sales comes in. Because of Magento's event-based system, it made the setup relatively easy. He includes the code for the observer on the Magento side and the Zend Framework-based logger code that it calls. Using the AS3Stomp library to make the connection, Kevin sets up the data provider for the Flex app to push the latest sale information into a list.

Sometimes the parsing and analysis process of PHP_Depend can consume a lot of time to finish, so I always put the shell aside and do something different. Normally I take a look at the shell every few minutes to check if the process has finished, but it also happens that I totally forget that I have started a PHP_Depend process on my system. So I need something that says to me, "Hey, mapi PHP_Depend has finished its job...", and here comes D-BUS in the game.

With the help of the DBus extension, he made a way to have the PHP_Depend process send a message (in his case one similar to a Growl popup) when the dependency checking is done. You'll need the 0.9.0 branch to get the "notify-me" command line option to make it all work.

If you wondered an API that requires polling isn't a very good thing for scalability. On my current setup I can pretty easily handle about 20 status requests per second on top of my normal traffic, the problem is its not hard for a bad polling implmentation being run by one user to make that many requests.

To solve this problem im adding an addition to the Webthumb API that will allow you to skip polling all together. The basic idea is that your make an API request and when your thumbnail is complete i'll make a GET request back too your server telling you that the request is complete.

It's a simple matter of including a new "notify" tag in the XML message to the server with a URL to make the callback to. He even includes some sample PHP code to get you started with the new feature. The script handles the automatic download of the thumbnails when called from the WebThumb service.