Drupal 8 Entity API

Las entidades se programan a través de la Entity API, y los campos a través de la Field API. Nuestro objetivo en Drupal 8 será programar más tipos de entidades y menos tipos de contenido.

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Introduction

2 types of methods (available extending Interfaces):

• Generic: $entity->id()
• Entity type: $node->getTitle()

2 types of Entity Types:

• Configuration Entity
• Content Entity
  • Building a Content Entity without Bundle.
  • Creating a custom content type that has 2 fields.
    • Adding a field to that custom content type: Add them with the UI, export them and lastly modify the yml files created.

About Bundles:

• They are Configuration Entities to enhance a Content Entity.
• Example: Article and Basic Page are Node Bundles.
• More info

About Annotations:

• You will need to use them when creating a Entity Type.
• At runtime D8 uses the doctrine annotation parser to turn the Entity into an PHP Object.

About Handlers:

• Defined in the Entity Annotation
• Common Handlers:
  • Storage Handler "storage" = "Drupal\node\NodeStorage",
  • Form Handler

  "form" = {
  "add" = "Drupal\block\BlockForm",
  "edit" = "Drupal\block\BlockForm",
  "delete" = "Drupal\block\Form\BlockDeleteForm",
  }
  

  • View builder "view_builder" = "Drupal\node\NodeViewBuilder",
  • List builder
  • Route provider
  • Access
  • Views data
  • Storage schema
  • Translation

About Links

• Defined in the Entity Annotation (Content and Configuration)
• To make these links accessible:
  • your module will need to implement its own routing.yml file
  • or use a route_provider handler in the entity annotation.

Entity Types

• They are typed objects defining a class that can be instanciated.

• Namespace: \Drupal\[module_name]\Entity

• Directory: src/Entity

• Annotations to be used: (\Drupal\Core\Entity\Annotation\EntityType)[https://api.drupal.org/api/drupal/core%21lib%21Drupal%21Core%21Entity%21Annotation%21EntityType.php/class/EntityType/8]

• Naming: Entity type names should be prefixed with the module name if the entity type and module name aren't the same.

• Interfaces: type hintfunctions and methods with Interfaces instead of classes.

  • Use descriptive method names starting with get/set/is only where needed. For example to access $node->status you will use $node->isPublished()

• Discoverability: Don't forget the id annotation key.

Have a look at theNode Entity

Have a look at Drupal 8 Entities Diagram

Working with the Entity API

• Generic methods:

  Entity::create()
  Entity::load()
  Entity::save()
  Entity::id()
  Entity::bundle()
  Entity::isNew()
  Entity::label()
  

• More methods:

  $entity->toUrl()->toString();
  $entity->access();
  

More info

• Entity API implements Typed Data
  • Examples
• Example of a Content Entity
• Example of Field Definition
  • Type of Fields, Widgets and Formatters
  • Creating a custom field
  • Creating Computed Fields
• Entities and multilang
• About Displays
• Make a Entity searchable
• Make a Entity revisionable and publishable

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Your own custom entity and plugin type

TODO: Insert data from the book

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Info from the Book "Drupal 8 Module Development"

• Have a look at this readme
• original code at packtpublishing

Getting Data from Entities

We use the entity.query service (QueryFactory) to get our data.

Method 1 using entity.query service

$query = \Drupal::entityQuery('node');

where node is the entity type

Method 2 using the entity_type.manager service

\Drupal::entityTypeManager()->getStorage('node')->getQuery();

Build Queries

// Example 1
$query
 ->condition('type', 'article')
 ->range(0,10)
 ->sort('created', 'DESC');
$ids = $query->execute();

// Example 2
$query
 ->condition('type', ['article', 'page'], 'IN');
$or = $query->orConditionGroup()
 ->condition('title', 'Drupal', 'CONTAINS')
$query->condition($or);
$ids = $query->execute();

More info at the QueryInterface class (especially the condition() method. Important: Queries for the Node entity take access restrictions into account using the context.