My rule of thumb for deciding what to post on this blog has been to document anything I've spent more than an hour trying to figure out. Today I've got a good one for anyone trying to create CCK fields as part of a module's installation process.

Back in Drupal 5 the Station module was made up of lot of custom code to track various values like a playlist's date or program's genre and DJs. During the upgrade to Drupal 6 I migrated that data into locked, CCK fields that were created when the module was installed. As people started to install the 6.x version of module I began getting strange bug reports about the Station Schedule that I couldn't seem to replicate on my machine.

For some work projects we've started making all the configuration changes via update functions. These get checked into version control and from there deployed to the staging site for testing, and then eventually deployed on the production site. The nice thing about update functions is that you can test it on staging and be sure that exactly the same changes will occur on the production site.

Here's a few examples, I'll continue to update it as I get more good examples.

Installing a module

Simple one liner to enable several modules:

I wasted more time that I want to admit do trying to figure this out. I was trying theme a specific CCK field named field_images on all the nodes where it appears. The devel_themer module was listing content-field-field_images.tpl.php as a candidate:

But after copying CCK's content-field.tpl.php into my theme and renaming it I couldn't seem to get the theme to pick it up. Roger López gave me the frustratingly simple answer on irc: "i think you need to have both templates in place"... duh. Copied content-field.tpl.php into my theme and everything worked great.

So building on my last post for creating CCK fields, here's some code I whipped up to migrate from the D6's core upload.module to the filefield.module. This isn't general purpose code but might help someone else out. The catch is I'd built a video node with and was using the upload module to attach exactly two files, an image and a video. The new node will have separate thumbnail and video fields. If you'll be moving to a multi-value field this code won't work for you.

The gist is the same as before, setup your field for video and your field for images then export using:

and
Then roll that into an update function that also moves the file data around in the database. Code is after the jump.

I spent some time today trying to figure out how to create a CCK field as part of an hook_update_N function. Unlike previous versions of CCK, in 6 it's very easy to manipulate the fields from code.

The first step is to create the field using CCK's UI. Once you've got the field setup the way you'd like it use PHP's var_export() to dump the contents of the node's field as an array:

This is a little snippet I came up with to get a block to show up on a single node type:

It uses the node type stored in the menu system so you don't have to match arg(0) etc.