RulesConditionBase.php

<?php

namespace Drupal\rules\Core;

use Drupal\Component\Plugin\Exception\ContextException;
use Drupal\Core\Condition\ConditionPluginBase;
use Drupal\rules\Context\ContextProviderTrait;

/**
 * Base class for rules conditions.
 *
 * @todo Figure out whether buildConfigurationForm() is useful to Rules somehow.
 */
abstract class RulesConditionBase extends ConditionPluginBase implements RulesConditionInterface {
    use ContextProviderTrait;
    use ExecutablePluginTrait;
    use ConfigurationAccessControlTrait;
    
    /**
     * {@inheritdoc}
     */
    public function refineContextDefinitions(array $selected_data) {
        // Do not refine anything by default.
    }
    
    /**
     * {@inheritdoc}
     */
    public function assertMetadata(array $selected_data) {
        // Nothing to assert by default.
        return [];
    }
    
    /**
     * {@inheritdoc}
     */
    public function getContextValue($name) {
        try {
            return parent::getContextValue($name);
        } catch (ContextException $e) {
            // Catch the undocumented exception thrown when no context value is set
            // for a required context.
            // @todo Remove once https://www.drupal.org/node/2677162 is fixed.
            if (strpos($e->getMessage(), 'context is required') === FALSE) {
                throw $e;
            }
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function negate($negate = TRUE) {
        $this->configuration['negate'] = $negate;
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function evaluate() {
        // Provide a reasonable default implementation that calls doEvaluate() while
        // passing the defined context as arguments.
        $args = [];
        foreach ($this->getContextDefinitions() as $name => $definition) {
            $value = $this->getContextValue($name);
            $type = $definition->toArray()['type'];
            if (substr($type, 0, 6) == 'entity') {
                if (is_array($value) && is_string($value[0])) {
                    $value = array_map([
                        $this,
                        'upcastEntityId',
                    ], $value, array_fill(0, count($value), $type));
                }
                elseif (is_string($value)) {
                    $value = $this->upcastEntityId($value, $type);
                }
            }
            $args[$name] = $value;
        }
        return call_user_func_array([
            $this,
            'doEvaluate',
        ], $args);
    }

}