1. Field API
From D7 to D8
Pavel Makhrinsky

2. About
Pavel Makhrinsky
Scrum master/Senior Drupal developer
Berlingske Media

3. History
CCK1 → Drupal 5, Drupal 6
CCK2, CCK3 → Drupal 5, Drupal 6
Drupal 7 → Field API
Drupal 8 → Entity Field API

4. D8 changes overview
Fields are
- base fields (properties)
- configurable fields (entities)
Fields are classes with interfaces
Configurable fields are separate kind of entity

5. Moving field across
instances

6. Typed Data API

7. Typed Data: definition
/core/lib/Drupal/Core/Entity/Plugin/DataType/EmailItem.php
class EmailItem extends LegacyConfigFieldItem {
static $propertyDefinitions;
public function getPropertyDefinitions() {
if (!isset(static::$propertyDefinitions)) {
static::$propertyDefinitions['value'] = array(
'type' => 'email',
'label' => t('E-mail value'),
);
}
return static::$propertyDefinitions;
}
}

8. Typed Data: implementation
/**
* Plugin implementation of the 'email' field type.
* @FieldType(
* id = "email",
* label = @Translation("E-mail"),
* default_widget = "email_default",
* )
*/
class ConfigurableEmailItem extends EmailItem {
public static function schema(FieldInterface $field) {
return array(
'columns' => array(
…
}
public function getConstraints() {
$constraint_manager = Drupal::typedData()->getValidationConstraintManager();
….
}
}

9. Default field types
File
Image
List
Number
Text
File
Image
List
Number
Text
EntityReference
Date and Time
Link
E-mail
Phone

10. EntityReference

11. Date and Time
Link, E-mail, Phone

12. New, best ever, widget

13. Validation API

14. Validators: D7
FAPI validation (https://drupal.org/project/fapi_validation)
Client side validation (https://drupal.org/project/clientside_validation)
$form['myfield'] = array(
'#type' => 'textfield',
'#title' => 'My Field',
'#required' => TRUE,
'#rules' => array(
'email',
'length[10, 50]',
array('rule' => 'alpha_numeric', 'error' => 'Please, use only
alpha numeric characters at %field.'),
array('rule' => 'match_field[otherfield]', 'error callback' =>
'mymodule_validation_error_msg'),
),
'#filters' => array('trim', 'uppercase')
);

15. Validators: D8
$definition = array(
'type' => 'integer',
'constraints' => array(
'Range' => array('min' => 5),
),
);
$typed_data = Drupal::typedData()->create($definition, 10);
$violations = $typed_data->validate();
Get applied constrains
$typed_data->getConstraints().

16. Accessing Field Data

17. Drupal 7
// Entities are complex, they contain other pieces of data.
$entity;
// Fields are not complex, they only contain a list of items.
$entity->image;
// Items are complex , they contain other pieces of data. They’re also
translatable and accessible (has permissions).
$entity->image[LANGUAGE][0];
// The file ID is a primitive integer.
$entity->image[LANGUAGE][0][‘fid’];
// The alternative text is a primitive string.
$entity->image[LANGUAGE][0][‘alt’];

18. Drupal 8: under the hood
$entity instanceof EntityInterface;
$entity->get('image') instanceof FieldInterface;
$entity->get('image')->offsetGet(0) instanceof FieldItemInterface;
$entity->get('image')->offsetGet(0)->get('alt') instanceof String;
is_string($entity->get('image')->offsetGet(0)->get('alt')->getValue());

19. Drupal 8
// With magic added by the Entity API.
$string = $entity->image[0]->alt;
// With more magic added by Entity API, to fetch the first item
// in the list by default.
$string = $entity->image->alt;

20. Language handling
@see Katya Marshalkina, 16:00

21. Implementing Formatter

22. Drupal 7
function hook_field_formatter_info()
function hook_field_formatter_settings_form()
function hook_field_formatter_settings_summary()
function hook_field_formatter_view()

23. Defining dependencies
// Field formatter annotation class.
use DrupalfieldAnnotationFieldFormatter;
// Annotation translation class.
use DrupalCoreAnnotationTranslation;
// FormatterBase class.
use DrupalfieldPluginTypeFormatterFormatterBase;
// Entityinterface.
use DrupalCoreEntityEntityInterface;
// Fieldinterface
use DrupalCoreEntityFieldFieldInterface;

24. Defining formatter info
/**
* @FieldFormatter(
* id = "foo_formatter",
* label = @Translation("Foo formatter"),
* field_types = {
* "text",
* "text_long"
* },
* settings = {
* "trim_length" = "600",
* },
* )
*/
class FooFormatter extends FormatterBase { }

25. Adding settings
public function settingsForm(array $form, array &$form_state) {
$element = array();
$element['trim_length'] = array(
'#title' => t('Trim length'),
'#type' => 'number',
'#default_value' => $this->getSetting('trim_length'),
'#min' => 1,
'#required' => TRUE,
);
return $element;
}

26. Adding summary
public function settingsSummary() {
$summary = array();
$summary[] = t('Trim length: @trim_length',
array('@trim_length' => $this->getSetting('trim_length'))
);
return $summary;
}

27. Settings form
Field name Formatter name Summary

28. Alter formatter
function foo_field_formatter_settings_summary_alter(&$summary,
$context) {
if ($context['formatter']->getPluginId() == 'foo_formatter') {
if ($context['formatter']->getSetting('mysetting')) {
$summary[] = t('My setting enabled.');
}
}
}

29. Implementing Widget

30. Drupal 7
hook_field_widget_info()
hook_field_widget_settings_form()
hook_field_widget_form()
hook_field_widget_error()

31. Widget implementation
Annotation
WidgetInterface::settingsForm()
WidgetInterface::formElement()
WidgetInterface::errorElement()
WidgetInterface::settingsSummary()

32. Useful links
Original initiative
http://entity.worldempire.ch/
Plugin API
https://drupal.org/node/1637614
Field API series from Realize
http://realize.be/drupal-8-field-api-series-part-1-field-formatters
http://realize.be/drupal-8-field-api-series-part-2-field-widgets
How Entity API implements Typed Data API
https://drupal.org/node/1795854
Typed Data API
https://drupal.org/node/1794140

33. Questions?