Drupal 7.x

It has been the first time since I started blogging somewhere in 2009 that a full calendar month (of April 2012) passed without me writing any blog in that month. It feels good to be back to the blogging world.

This was the most time consuming aspect for the recent port of my Document module for Drupal 7.

You would be knowing that File system API underwent a complete revamp in Drupal 7 (see this and this link, a very good introduction of the changes and new concepts is available on Randy Fay's blog). In Drupal 6, handling file uploads was this easy:

While working on the 7.x port for my Document module for Drupal day before yesterday, I had a pretty anxious moment. As you would know, the new DBTNG database abstraction layer in Drupal 7 fundamentally changes the way your module code interacts with the db. Now instead of writing raw Sql queries, you use a set of high level objects to specify the various components of your query using a series of methods which is then translated to Sql by the DBTNG layer and executed against the database. Sample this for example:

Drupal 7 brings some important API changes and enhancements to the table, one of them being the ability to control precisely the order of execution of a particular hook between modules.

I was asked by a client last week if it is possible to control execution of specific hooks between modules. Here is the (very precisely) framed question:

While editing content on a client site last week, I got a rather confusing error in Google Chrome Developer tools:

Refused to execute a JavaScript script. Source code of script found within request.

I was incorporating Google Maps on a page through a Block and the block content had some javascript code in it. But on saving the block, two issues surfaced: 1) I got the above error in Chrome Dev tools console and 2) The Map did not show up on the page.

My recent blog post on Creating Paged and Sorted tables in Drupal 7 got a comment today asking if it was possible to implement Paging and Sorting in Drupal tables via Ajax, instead of regular Page refreshes that Drupal does by default.

My earlier blog post on creating Drupal 6 tables (I mean html tables and not database tables) complete with paging, sorting, sticky headers and other Drupal table features attracts a decent number of visitors (Analytics tell me). So, I thought of publishing another post with the same theme but this time for Drupal 7, as there are significant changes on how you would create Html tables with Drupal 7 with all the features.

Let me clarify staright away that the code below has been tested successfully against Drupal 6 only. But I believe it should work with Drupal 7 also with minor changes (if any required). Okay now, let's come to the point.

Last week, I was trying to add a custom validation method for node form of a particular content type in Drupal. My initial approach was as naive as specifying my custom validation method in hook_form_alter, something like the following:

function mymodule_form_alter(&$form, &$form_state, $form_id) {
	switch($form_id) {
		case 'artist_node_form':
$form['#validate'][] = '_mymodule_custom validation';
			break;
	}
}

I needed to remove the default "-None-"/"-Select-" option that Drupal's Form API adds to "select" form elements. Let's take an example. Consider the following "select" element definition for a form:

$element = array (
			'#type' => 'select',
			'#options' => array (
							1 => 'Very poor',
							2 => 'Not that bad',
							3 => 'Average',
							4 => 'Good',
							5 => 'Perfect',
						),
			'#required' => TRUE,
			'#title' => 'Rating',
		);