It wasn't readilly apparent to me how to loop through some datagrid rows in Flex. Finally, I came across Abdul Qabiz's DataGridDataExporter class, which basically does just that.

The key is to set up a cursor that will loop through the Data Provider for the datagrid.

Something like this:

That's all there is to it.

This is old news now, but it's worth noting that AppleInsider released a 3-part series of articles about Flash. Check them out here:

• Part 1: Adobe in the History and Future of Flash
• Part 2: The Many Enemies and Obstacles of Flash
• Part 3: Adobe Fights for AIR with the Open Screen Project

Whether you love Flash, hate Flash, love Adobe, hate Adobe, or are neutral with the whole thing, this series is disturbingly prejudicial and biased. Comments on the posts even say as much. This is certainly disappointing, because I like AppleInsider, Apple, Adobe, and Flash. But these articles have a predisposition that results in negative interjected commentary in what would otherwise have been an interesting consideration of the history of Flash.

Nothing Earth-shattering here. I've just come to appreciate how useful the memento design pattern can be to do web services a bit more efficiently sometimes.

My web service is a facade CFC powered by objects being generated by Transfer and ColdSpring. So I conveniently have access to the objects' getMemento() or getPropertyMemento() methods.

I had a method in the web service that would accept several arguments and perform the simple task of processing them and saving them to the database. It returned a single boolean indicating success or failure.

The web service is just used by another web server that doesn't have access to the database and can't run Transfer (because it is currently running CFMX 6). This web server hosts a page with a form; when the user submits the form, the action page invokes the web service to process and save the information.

I needed the action page to display some data that wasn't available in the form data that was transmitted. For instance, a pull-down menu allowed the user to select from a list of sessions, but all that is transmitted is the database ID of the session they chose. My action page can't display any details about that session unless it makes another web service call to retrieve the details of that session. And I have to write the code for that web service method, which up to this point was unnecessary.

Aha! I changed the web service to return a struct that still contained the success/failure boolean, but also contained mementos of the objects that were created or referenced when processing the request. Now my web server invoking the web service has all the details of the session at its disposal for display on the action page.

What's the big deal, right? Who cares about one more web service call? Well, I'd like to keep the chatter between the two machines down to a minimally required amount, and besides, thanks to getMemento(), adding all of that data to the web service's response took one line of code, and way less time than it would take to write that extra web service method to retrieve session data, and also way less time than it took to even write this blog post.

Here's the general thought process of the code in the web service (abbreviated to just show the point of mementos):

Note to self (the Flex newbie): Test your HTML wrapper for your SWF files to make sure that the user experience is a good one when you're setting up your Flex apps on your site! I took the HTML wrapper generated by Flex Builder and modified it to fit into my page. While doing so, I forgot to include the playerProductInstall.swf file with my app, so when a browser with an older Flash Player viewed the page, the JavaScript I had in place to call playerProductInstall.swf would hang since it couldn't find it. The detection for when no Flash Player is present at all (or only a really old version) was also a bit ungraceful.

But I was clueless to these poor experiences since I hadn't tested these scenarios. Fortunately, my app was just released, and only to a beta crowd.

To test the absence of Flash Player, you can download a Flash Player Uninstaller and uninstall Flash Player. I'm not sure what the best way is to install and test an old version of the Flash Player; I just had a virtual machine that had an old version on it, so I used that because it was convenient. If you google for "download flash player 8", there are some non-Adobe links that appear to be valid links, but I did not try these.

Adobe has a Flash Player Detection and Installation support page that is helpful as well.