NOTE: Support of Dreditor has been nominal for a while. It's still the preferred tool for enhancing Drupal's issue queue, but keeping track of what the "official" version is can be tricky. For now, we recommend https://dreditor.github.io/. There's also been work happening to incorporate many of Dreditor's features right into Drupal.org itself. See https://www.drupal.org/project/drupalorg/issues/1673278

Dreditor is a great community tool that assists with things like patch reviews, and generally interacting with the Drupal.org issue queue. Dreditor is not a Drupal module, but is a plugin script you use in your browser. In this lesson, Joe walks through how to get Dreditor installed (on Chrome and Firefox), and then shows you how to use it to make your work in the issue queues more efficient.

Additional resources

Dreditor project
Written Dreditor tutorial for this video

Revisions are an important concept in a content management system. Keeping track of all the edits that have been made to a particular entity over the course of its lifetime. A paper trail or sorts. This lesson takes a look at what is required in order to make our Entities support revisions.

If you've worked with Drupal's node system and enabled revisions then you've seen Drupal's basic revision handling in action. Every time you save a node, it creates a new version of that node. You can roll back to previous versions and keep track of how a piece of content has changed over time. Entity API also supports the concept of revisions and in this lesson we're going to take a look at adding revision support for our video entities.

In order to take advantage of this feature, we'll need to modify our database schema to accommodate storing multiple versions of the same entity. We'll move all fields that we want to make "revisionable" into a separate table and set up a new unique version ID field so that we can keep track of revisions.

Then we will update our hook_entity_info implementation to tell the API that we want to use the revision system and make some changes to the code in our VideoEntityController so that when an entity is updated we save a revision instead of overwriting the current data.

Finally we'll need to write a simple UI for viewing older versions of our video entity because the Entity API does not provide us with this code by default.

If you've done any module development, you're probably familiar with hook_node_view and Drupal's arrays of doom. In this lesson we'll show you how to get easier access to the same information using entity metadata wrappers. We will use the entity_metadata_wrapper function to retrieve a new EntityMetaDataWrapper object that provides an interface for easily accessing an entities property and field values. We'll use the getPropertyInfo method to expose information about individual properties, and the getIterator method to access fields that contain multiple values, such as tags. You'll see that by using meta data wrappers you can also access properties on referenced entities, such as the email address of the author of a node, without having to load that information independently.

Metadata wrappers also provide a consistent way to access properties common to all entities. For example, every entity in Drupal has a unique ID property or a human readable label, but these properties often have different names. User name vs. node title. Metadata wrappers allow you to access this information in a consistent way.

Additional resources

Entity metadata wrappers

In order to make the most of the entity APIs integration with other modules, such as Views, we need to describe the properties of our entity in more detail. The API can infer some information about a property based on our schema but we need to tell it that the integer stored in the updated_at column is actually a timestamp. We will do this by implementing hook_entity_property_info() and describing each of our entities properties. With these definitions in place you will be able to use the formatters in Views much like you would for individual fields on content types provided by core.

Note: Before you implement hook_entity_property_info() the API makes an educated guess about each property but once you've defined a single property, the API expects you to define all of the properties for your entity. Use the .install file in your module to get a complete list of the properties you need to define with hook_property_entity_info. You can also define additional properties that aren't mapped to fields in the database (these can be used for static properties).

Additional resources

Entity Property Information

This lesson takes a look at exposing the data in our entities to views. Lucky for us the entity API handles a lot of this for us. We’ll take a look at what we get for free, using the EntityDefaultViewsController class provided by Entity API module. We'll also discuss ways that we can customize this controller, which we'll tackle in a later lesson.