Facebook Cookbook

FBML Caching

Problem

I’d like to take advantage of Facebook’s FBML caching to store a block of FBML that I use often.

Solution

Use the fb:ref tag. There are two ways to use it, depending on how you’ve architected your app:

By handle

If you’re developing heavily in the Facebook API, this is probably the better method for you. Use the API call setRefHandle to initialize your handle:

$facebook->api_client->fbml_setRefHandle("MyUniqueAppHandle", "Some FBML Content");

Then insert the fb:ref tag in your FBML to pull the block out and display it:

<fb:ref handle="MyUniqueAppHandle" />

Now when you want to update the content, just call setRefHandle again with new FBML and it will change everywhere you’ve put fb:ref tags.

By URL

If your app is based more on different files or pages on a server, you can still put FBML into the cache by giving it a unique URL. Create a page that only renders out the block you’d like stored, and then use the alternate form of the fb:ref tag:

<fb:ref url="http://www.someserver.com/cacheThisPage.php" />

When you want to change the content, update your page on your server and then make a simple API call to tell Facebook that it needs to reindex that URL:

$facebook->api_client->fbml.refreshRefUrl("http://www.someserver
.com/cacheThisPage.php")

Discussion

There are lots of places you might use this—really wherever you have a block of relatively static content you want to display—but the best use is probably for Profile Boxes that aren’t user-specific. In that case, you’ll want to ...