DataReferenceBase.php

<?php

namespace Drupal\Core\TypedData;


/**
 * Base class for typed data references.
 *
 * Data types based on this base class need to be named
 * "{TARGET_TYPE}_reference", whereas {TARGET_TYPE} is the referenced data type.
 * For example, an entity reference data type would have to be named
 * "entity_reference".
 * Beside that, implementing classes have to implement at least
 * \Drupal\Core\TypedData\DataReferenceInterface::getTargetIdentifier().
 *
 * @see \Drupal\Core\TypedData\DataReferenceDefinition
 */
abstract class DataReferenceBase extends TypedData implements DataReferenceInterface {
    
    /**
     * The referenced data.
     *
     * @var \Drupal\Core\TypedData\TypedDataInterface
     */
    protected $target;
    
    /**
     * {@inheritdoc}
     */
    public function getTarget() {
        return $this->target;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getValue() {
        if ($target = $this->getTarget()) {
            return $target->getValue();
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function setValue($value, $notify = TRUE) {
        $this->target = $this->getTypedDataManager()
            ->create($this->definition
            ->getTargetDefinition(), $value);
        // Notify the parent of any changes.
        if ($notify && isset($this->parent)) {
            $this->parent
                ->onChange($this->name);
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function getString() {
        if (!method_exists($this, 'getType')) {
            throw new \BadMethodCallException(get_class($this) . '::getType() not implemented');
        }
        return (string) $this->getType() . ':' . $this->getTargetIdentifier();
    }

}