OptionalContextCondition.php

<?php

namespace Drupal\condition_test\Plugin\Condition;

use Drupal\Core\Condition\ConditionPluginBase;

/**
 * Provides a condition with an optional node context.
 *
 * The context type entity:node is used since that would allow to also use this
 * for web tests with the node route context.
 *
 * @Condition(
 *   id = "condition_test_optional_context",
 *   label = @Translation("Optional context"),
 *   context_definitions = {
 *     "node" = @ContextDefinition("entity:node", label = @Translation("Node"), required = FALSE),
 *   }
 * )
 */
class OptionalContextCondition extends ConditionPluginBase {
    
    /**
     * {@inheritdoc}
     */
    public function evaluate() {
        // Grant access if no context value is given.
        return !$this->getContextValue('node');
    }
    
    /**
     * {@inheritdoc}
     */
    public function summary() {
        return $this->t('Context with optional context.');
    }

}