"Generic" Field Source Plugin Deriver

Hi Christian,

Thanks for this issue. I hope I am understand what you are trying to do achieve here. I not, I will move this to its own ticket.

They are 3 levels in Field API and 3 kinds of prop types:

Indeed, we use typed_data property only with scalar prop types nowadays:

 $ grep -r typed_data src/Plugin/UiPatterns/PropType
src/Plugin/UiPatterns/PropType/UrlPropType.php:  typed_data: ['uri']
src/Plugin/UiPatterns/PropType/StringPropType.php:  typed_data: ['string']
src/Plugin/UiPatterns/PropType/NumberPropType.php:  typed_data: ['decimal', 'float', 'integer']
src/Plugin/UiPatterns/PropType/EnumPropType.php:  typed_data: ['float', 'integer', 'string'],
src/Plugin/UiPatterns/PropType/BooleanPropType.php:  typed_data: ['boolean']

Let's focus on the 3 red crosses (❌) instead

So we have much to do to cover the full field API.

Every component prop type has a (JSON) schema, every prop type has a (Typed data) schema. They may be matchable.

Example: Icon field with an Icon prop

Icon field:

  public static function propertyDefinitions(FieldStorageDefinitionInterface $field_definition): array {
    $properties = [];
    $properties['target_id'] = DataDefinition::create('string')
      ->setLabel(new TranslatableMarkup('Icon ID'))
      ->setRequired(TRUE);
    return $properties;
  }

is converted to JSON schema:

type: object
properties:
  target_id:
    type: string

Icon prop type:

type: object
properties:
  pack_id:
    "$ref": ui-patterns://identifier
  icon_id:
    type: string
  settings:
    type: object
required:
- pack_id
- icon_id

Not easy to map because it seems icon field has a single property (target_id) for 2 prop types properties (pack_id and icon_id). Maybe with a separator. Let's check that with UI Icon team.

Example: LinkItem field to Links prop

LinkItem field type :

   public static function propertyDefinitions(FieldStorageDefinitionInterface $field_definition) {
        $properties['uri'] = DataDefinition::create('uri')->setLabel(new TranslatableMarkup('URI'));
        $properties['title'] = DataDefinition::create('string')->setLabel(new TranslatableMarkup('Link text'));
        $properties['options'] = MapDataDefinition::create()->setLabel(new TranslatableMarkup('Options'));
        return $properties;
    }

is converted to JSON schema:

type: object
properties:
  title:
    type: string
  uri:
    "$ref": ui-patterns://url
  options:
    type: object

Links prop type:

type: array
items:
  type: object
  properties:
    title:
      type: string
    url:
      "$ref": ui-patterns://url
    attributes:
      "$ref": ui-patterns://attributes
    link_attributes:
      "$ref": ui-patterns://attributes
    below:
      type: array
      items:
        type: object

Not bad :) But url and uri property names don't match, so we can have 2 strategies:

• We don't care about the property names ("title", "uri", "options"), we care only about the type and we let the builder do the mapping.
• Can we use a PropTypeAdapter plugin transforming uri and url for that? They were not made for this kind of flow, but it may work.

Example: Multivalued StringItem field to List prop

StringItem field:

  public static function propertyDefinitions(FieldStorageDefinitionInterface $field_definition) {
    $properties['value'] = DataDefinition::create('string')
      ->setLabel(new TranslatableMarkup('Text value'))
      ->setSetting('case_sensitive', $field_definition->getSetting('case_sensitive'))
      ->setRequired(TRUE);
    return $properties;
  }

Is converted to this JSON schema:

type: object
properties:
  value:
    type: string

So this when multivalued:

type: array
items:
  type: object
  properties:
    value:
      type: string

List prop type:

type: array
items:
    type: ['string', 'number', 'integer']

It doesn't seem obvious at first, but it may be good match if we flat the single "value" field property.

Conclusion

None of my examples were a perfect match. But each of them is showing mechanism worth to study. There is something smart to do here.

So to handle icons the ui icon module needs three sources. One for pack_id, icon_id and one for settings.

/**
 * Plugin implementation of the source_provider.
 */
#[Source(
  id: 'icon_pack_id',
  label: new TranslatableMarkup('Foo Field(ui_patterns_test)'),
  description: new TranslatableMarkup('Foo description.'),
  prop_types: ['string'],
  deriver: CustomEntityPropertySourceDeriver::class,
  metadata:
  [
    'field_type' => ['icon'],
   'field_property' => ['target_id']
  ],
)]
final class IconPackId extends SourcePluginBase {
DO MAGIC TARGET EXPLODE HERE

So no magic just not writing a deriver