drupal 7

When you import data with Migrate (http://drupal.org/project/migrate) it is nice to have ability to update already imported data if source has changed. To track updated data Migrate uses highwater marks (more on this: http://drupal.org/node/1223936). Highwater mark is a column of a source data which has timestamp of the last data change. However, the problem with highwater mark is that you don't always have such "time tracking" enabled on source's page.

"How to find form id in Drupal" is one of the most popular questions, especially for the beginners.

More experienced developers know that to find form id you need to either look into the DOM source code or to create your own hook_form_alter() function like this:

function YOUR_MODULE_NAME_form_alter(&$form, &$form_state, $form_id) {
  dpm($form_id);
}

Time from time, while doing your custom Drupal code, you may want to load only one or several specific fields from a defined set of entities. So actually you have three approaches to this:

1. Query for entity/node set and load whole entities to get desired fields data. Works, but not a performant solution.

2. Make a direct sql query and get desired fields out of your database. Works too, is the fasted in terms of performance solution, but not too flexible and portable.

3. Leverage EntityFieldQuery() and field_attach_load(). This approach is not as fast as the second, but way more faster than loading whole nodes, it is flexible and uses field caching mechanism. If you'll decide to change your database backend later in the future, let's say to MongoDB, you'll be able to switch without changing a line in your code, neat!

A week ago Packt Publishing approached and asked me to review their new book called “Drupal Rules How-To” written by Robert Varkonyi. I like getting books for a review, because it motivates you to read. With my working schedule it’s hard to find time for another tech read, but when you give a promise to someone, you can’t retreat ;) So I agreed, read the book and here is my unbiased review.