Drupal

I recently noticed a strange little issue with Drupal 7 that seemed like either an oversight or a decision I don't agree with. Essentially, when a node is created with a menu item in place the extended flag on the menu will not be set, but the control is also not available on the menu admin page. This means that when you are trying to print out a hierarchical menu structure you need to create the page, go into the menu admin area, access the menu, click on edit to access the menu item and change the setting there.

To get around this I set about creating a little module that would add a form control to the menu options section on the node edit form. This single checkbox is used to override any settings that the menu module creates with regards to the extended menu parameter.

The first thing to do is create a simple info file for the module. I include this here for completeness.

During my work developing Drupal sites I am quite often asked if I can provide a example of form elements for designers. This is so that they can test their designs with all possible form elements that might appear in a Drupal install and make sure that the theme we create will be robust and future proof. I often find myself forgetting how to create, say, a multi select element and needed a sort of cheat sheet that I could look form elements up on.

To this end I sat down and created a list of all of the Drupal form elements and packaged them into a module so that when the path 'form_elements' is loaded a very large form with lots of elements will be rendered. There is even a tabledrag form component in there, which is used quite a bit within the Drupal administration pages.

The Login Destination module is a neat little module that allows site admins to customize where the user will be sent to when they login. It provides a few of different ways of customizing, including a PHP snippet box that allows fine grained control.

What I needed to do on a recent project was to change the login destination for a single user role, but redirect everyone else to their user profile page. This required the use of the PHP snippet box. In order to get access to the current user object I had to include it into the scope of the PHP snippet code by using the following.

The Drupal 7 Queues API is a few feature of Drupal and provides a first in first out data structure that is used internally by Drupal itself and can be completely customised.

The Queues API isn't just a part of the codebase of Drupal, it is used internally as part of several different processes. The Batch API, which allows lots of things to be done at once, is built upon the Queues API and provides some customised queue classes. I won't be going into the batch API in this post, but I might cover it in later posts.

The new cron system in Drupal 7 uses the Queues API heavily. It works by allowing other modules to create queue items during their normal hook_cron() calls, which are then run afterwards. Each module that wants to include an item in the system cron queue can do so by implementing a hook called hook_cron_queue_info(), which tells cron what function to callback when the queue items are retrieved.

This weekend I attended the Druapl7Camp 2011 in Leeds and so I booked a hotel room for the weekend and managed to find the right place on Saturday morning. I was one of the first to arrive and was able to greet people as the came through the door. With coffee flowing nicely and the wifi appearing to be stable we all set down to the first session.

Sometimes the most complex part of using SimpleTest is making sure that everything is working as it should before you start your tests. This means setting up the correct modules and creating the correct content types in advance. Because SimpleTest works by issuing CURL requests to pages the most reliable way of doing certain tasks is to use the administration forms as you normally would. Taking an example, if you want to enable a block from a module you should submit the block form, adding the blocks you need to the various different regions this like.

// Enable the different blocks
$blocks = array(
    'my_awesome_block' => 'header'
);

$this->drupalPost('admin/build/block', $blocks, 'Save blocks');

However, if you haven't given the current user 'administer blocks' access, or have forgotten to log them in, then you will get an access denied error when you try to do this.

I was testing out a new Drupal project build and found this strange error when uploading files to nodes using the Upload module. This error produced a lot of warning messages that appeared on the screen (in the process alarming my project manager) but appeared to have no impact on the actual function of the module, or the file uploaded. Essentially, when a file was uploaded the following errors were produced.

One new feature of Drupal 7 is that any title you give a node will be copied to the menu title field when you create a menu item. I wanted to replicate this functionality in Drupal 6 and so I created a function that did just that. I have used this function a few times in different projects so I'm posting it here.

This code uses the drupal_add_js() function to push a small amount of JavaScript code into the page when a node is added or edited. The hook hook_init() is used to add this content as it is run very early on in the Drupal boot cycle. I have tried putting this code into other hooks (like hook_preprocess_page()) but it isn't included, I would look into this further but this solution seems to work well.

Whilst creating a large and complex form in Drupal 6 recently I hit upon a problem that took me a couple of hours to solve so I am posting the solution here in case anyone else gets similarly stuck. I am also writing this down so that I can remember the strategy in case I have to do the same thing again.

What I was doing was creating an event booking form. The form allowed users to select from a number of times slots in a select list, but each time had a limited number of bookings. When the user submitted the form and all allocated slots for their selected time were fully booked they were shown a message asking them to select a different time slot. The original time was removed from the select list so that the user didn't try to select it again. This was fine and it all worked as expected but when this happened I also got the following error message from Drupal.

I discovered a little issue recently with the Profile module in Drupal 6 and after finding the solution I thought I would post it here in case it helps anyone else.

The problem occurs when using the list selection form item in a specific way. This form item works find for just about every situation, except one special case. Lets assume that you wanted to ask a user a question which requires a number between zero and four; you enter the following into the selection options box.

0
1
2
3
4

This is saved fine, but when the form is rendered it doesn't actually print out the option to select 0, which is odd as the value is definitely saved in the database and can be reedited in the form admin.