Creating Dynamic DIV tables

While working through making a custom Facebook application (which isn't finished, but will be soon!) I wanted to use a DIV-based layout for my data, rather then the simple TABLE tags. However, it was going to be somewhat dynamic (as in, number of rows would be determined by the data). So here is how I did the creation of the table using JSTL and DIVs. Feel free to enjoy/offer your suggestions.

<div class="div_table">
<c:forEach items="${list}" var="item" varStatus="status">
<c:if test="${status.index % 3 == 0}">
<c:out value="<div style='clear:both;'></div>" escapeXml="false"/>
</c:if>

<div class="div_cell" style="float: left;">
{ put stuff here }
</div>
</c:forEach>
<c:out value="<div style='clear:both;'></div>" escapeXml="false"/>
</div>

The line:

<c:out value="<div style='clear:both;'></div>" escapeXml="false"/>

Basically is like a "new row" signal. In my case, I wanted a 3 column table.

fb_sig parameters

I've been working away at building my own java library for Facebook applications (Java-Spring-Book) and came across something today that was a little different.

For Facebook API calls, you need to have a session_key as one of your parameters. You get this key by asking for it with authToken. Nothing special here. So, my original plan was to store this session_key so that I didn't have to keep requesting one (and I'm sure many other people would do the same). For simplicity, I decided to store the key in the user's session.

As I started working away, I noticed that I wasn't able to store the key in the session (it was always blank on subsequent calls). Without going into the session more, I decided to try simple http cookies. They may not be the greatest, but they should do the job. Again, they weren't working. Cookies didn't seem to persist across subsequent calls. Strange, no?

From the looks of it, my code was working totally fine. There really wasn't any information in subsequent sessions or cookies. And from what I can tell, that's all by design. Here's my theory as to why:

• In your application setup, you can tell Facebook whether you want to use FBML or an iFrame to display your content (FBML is a bunch of custom tags that make building apps easier)
• In order to properly render your page inside of Facebook, a request from the user goes to Facebook to show an app. Facebook then sends a seperate, distinct request to my server to get my content. However, this request is different then the user's request, and appears to be blank each time (no persisted info). The result? No cookies for you!

So how can I go about "storing" a session_key? I don't think I have to. From the looks of it, when Facebook makes a request for my page it appends a bunch of "fb_sig_" parameters (including one for session_key). It looks like I can use these parameters in my calls.

I took a quick look through the Facebook docs and couldn't find anything. Anybody know where this might be at?

Building Custom Facebook Apps

Facebook...what a great thing. Taking a simple idea of friends, Mark has been able to create a company that is probably worth something in the billions. Not bad for someone whose my age. So now that I am in fourth year at UW for Systems Design, my friends and I decided that a design project around Facebook might become profitable (not to mention fun).

Now that Facebook has opened its developer platform up, anyone can make their own applications that users can add to their profile, and for the lucky ones, make a little money. There's even companies (such as Slide) that are based specifically around building custom apps.

Our goal? Well...something that makes something about building apps a little easier. And quite obviously, we have no idea what that something is.

So, now 2 months later, we are well on our way. The 2 other group members are looking at a fairly well-developed PHP library that Facebook provides. They seem to be having a lot of fun and finding it rather simple. And me? Not as much fun. I decided to take the Java approach. And let's just say it hasn't been the most enjoyable or easy experience of my life. But I am learning a lot.

Why isn't it so fun? Well, the Java library Facebook provides is for desktop applications, not web based apps...so some subtlety's cause some problems. But, me, being the try-hard that I am (ha!) has decided to build my own Java library...no small feat mind you.

But I did try something I've never done before (and have been silently inspired by my boss): I've started an open source project around it: Java Spring Book. Right now, it's in a very early stage...I'm still trying to figure out the details. Hopefully, someday it will be in a position to offer some help to new developers (who are like I was when I started).