We just posted our new online tool which generates a full custom Drupal module. This post talks about that tool and how modules fit in to the Drupal ecosystem.

A little background first. Occasionally Jason and I will answer questions on the Drupal.org Module Development and Code Questions forum. Some time last year, someone asked for a "Hello World" module.  A "Hello World" application is a barebones implementation of any development environment. If you read any books that cover programming languages they inevitably start with a "Hello World" example. So on the Drupal.org forum, I posted a simple "Hello World" module for Drupal 7. That post generated an unusual amount of interest. Therefore we decided, rather than just repost the "Hello World" example, we would create a tool to allow folks to generate their own.

So our online tool allows you to name the module and customize the package name. The module itself, is still only going to do 2 things:

• Creates a menu item link (so folks can click and invoke the hello function).
• Creates a custom function which simply displays "Hello World"

However, for a developer, the tool

• Creates the proper directory structure and name.
• Creates the proper file listings.
• Creates a custom "info" file that allows you to install your custom module in your Drupal installation.
• The source code includes an implementation of hook_menu().

So the developer gets a starter it. You can add addition functions, menu items etc. The proper naming conventions are started for you (by our tool).

In our "proof of concept" module, we employ ajax to perform a partial page repaint. The following are screen shots of the "proof of concept" module (my_color). We demonstrate the initial form and report state, invalid data entered and finally valid (success) data entered.

In example below we demonstrate some of the new Drupal 7 database abstraction layer features.

To add a record we are using db_insert(). "db_insert()" is more elegant than it's closest Drupal 6 counterpart (e.g. drupal_write_record). The method db_insert() returns the database key generated by the database.

In our hook_form() implementation, we added ajax attributes to a couple of our form elements. The example below is our ajax response handler. In Drupal7 you can use a simple response handler which simply updates a single element (not shown here), or you can send a batch of client side commands. Our example below sends a batch of client side directives.

We are using the Drupal7 implementation of theme_table to render our report. As of version alpha 6, theme_table() requires you to include at least 2 data rows (note! may be a bug).

In the example below, we check to see if we have any records to report.

If we don't have any records to report, we notify the user there is no records, create a default display.

If we do have records to display, we add the array elements to our $vars array structure.

Drupal 7 adds "ajax" attributes to the Form API (FAPI).

In our example below, we've added ajax attributes to our "report" button. When a user "clicks" on the button, we will send a request to a server side handler named "my_color_ajax_response". When the server side handler sends a response, we replace the contents of the html div element "report_table". We use the tag "id" attribute to identify the appropriate target html div tag.

Drupal 7 automatically adds database tables described with hook_schema. In our example below, even though we don't have an implicit hook_install or hook_uninstall method defined, Drupal adds the "my_color" database table when our module is enabled, and drops the "my_color" database table when our module is un-installed.

Drupal 7 introduces dynamic class loading. When you package your modules, you need to supply Druapl with a ".info" file. Inside the ".info" file you now declare an array of file listings. Drupal's new Module Registry inventories the file listings and dynamically loads method and objects as needed.

In our example below, we have have a file listing called "my_color_class.inc". The file listing includes several application objects. Before Drupal 7 we would need to use an "include..." statement in any other file listing before we could use those objects.

my_color.info