Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\Component\Plugin\Context;
Chris@0: 
Chris@0: use Drupal\Component\Plugin\Exception\ContextException;
Chris@0: use Symfony\Component\Validator\Constraints\Type;
Chris@0: use Symfony\Component\Validator\Validation;
Chris@0: 
Chris@0: /**
Chris@0:  * A generic context class for wrapping data a plugin needs to operate.
Chris@0:  */
Chris@0: class Context implements ContextInterface {
Chris@0: 
Chris@0:   /**
Chris@0:    * The value of the context.
Chris@0:    *
Chris@0:    * @var mixed
Chris@0:    */
Chris@0:   protected $contextValue;
Chris@0: 
Chris@0:   /**
Chris@0:    * The definition to which a context must conform.
Chris@0:    *
Chris@0:    * @var \Drupal\Component\Plugin\Context\ContextDefinitionInterface
Chris@0:    */
Chris@0:   protected $contextDefinition;
Chris@0: 
Chris@0:   /**
Chris@0:    * Create a context object.
Chris@0:    *
Chris@0:    * @param \Drupal\Component\Plugin\Context\ContextDefinitionInterface $context_definition
Chris@0:    *   The context definition.
Chris@0:    * @param mixed|null $context_value
Chris@0:    *   The value of the context.
Chris@0:    */
Chris@0:   public function __construct(ContextDefinitionInterface $context_definition, $context_value = NULL) {
Chris@0:     $this->contextDefinition = $context_definition;
Chris@0:     $this->contextValue = $context_value;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function getContextValue() {
Chris@0:     // Support optional contexts.
Chris@0:     if (!isset($this->contextValue)) {
Chris@0:       $definition = $this->getContextDefinition();
Chris@0:       $default_value = $definition->getDefaultValue();
Chris@0: 
Chris@0:       if (!isset($default_value) && $definition->isRequired()) {
Chris@0:         $type = $definition->getDataType();
Chris@0:         throw new ContextException(sprintf("The %s context is required and not present.", $type));
Chris@0:       }
Chris@0:       // Keep the default value here so that subsequent calls don't have to look
Chris@0:       // it up again.
Chris@0:       $this->contextValue = $default_value;
Chris@0:     }
Chris@0:     return $this->contextValue;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function hasContextValue() {
Chris@0:     return (bool) $this->contextValue || (bool) $this->getContextDefinition()->getDefaultValue();
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function getContextDefinition() {
Chris@0:     return $this->contextDefinition;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function getConstraints() {
Chris@0:     if (empty($this->contextDefinition['class'])) {
Chris@0:       throw new ContextException("An error was encountered while trying to validate the context.");
Chris@0:     }
Chris@0:     return [new Type($this->contextDefinition['class'])];
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function validate() {
Chris@0:     $validator = Validation::createValidatorBuilder()
Chris@0:       ->getValidator();
Chris@0:     return $validator->validateValue($this->getContextValue(), $this->getConstraints());
Chris@0:   }
Chris@0: 
Chris@0: }