Context.php

1. 8.x drupal/core/lib/Drupal/Core/Plugin/Context/Context.php
2. 8.x drupal/core/lib/Drupal/Component/Plugin/Context/Context.php

<?php

/**
 * @file
 * Contains \Drupal\Component\Plugin\Context\Context.
 */
namespace Drupal\Component\Plugin\Context;

use Drupal\Component\Plugin\Exception\ContextException;
use Symfony\Component\Validator\Constraints\Type;
use Symfony\Component\Validator\Validation;

/**
 * A generic context class for wrapping data a plugin needs to operate.
 */
class Context implements ContextInterface {

  /**
   * The value of the context.
   *
   * @var mixed
   */
  protected $contextValue;

  /**
   * The definition to which a context must conform.
   *
   * @var array
   */
  protected $contextDefinition;

  /**
   * Sets the contextDefinition for us without needing to call the setter.
   */
  public function __construct(array $context_definition) {
    $this->contextDefinition = $context_definition;
  }

  /**
   * Implements \Drupal\Component\Plugin\Context\ContextInterface::setContextValue().
   */
  public function setContextValue($value) {
    $this->contextValue = $value;
  }

  /**
   * Implements \Drupal\Component\Plugin\Context\ContextInterface::getContextValue().
   */
  public function getContextValue() {
    return $this->contextValue;
  }

  /**
   * Implements \Drupal\Component\Plugin\Context\ContextInterface::setContextDefinition().
   */
  public function setContextDefinition(array $context_definition) {
    $this->contextDefinition = $context_definition;
  }

  /**
   * Implements \Drupal\Component\Plugin\Context\ContextInterface::getContextDefinition().
   */
  public function getContextDefinition() {
    return $this->contextDefinition;
  }

  /**
   * Implements \Drupal\Component\Plugin\Context\ContextInterface::getConstraints().
   */
  public function getConstraints() {
    if (empty($this->contextDefinition['class'])) {
      throw new ContextException("An error was encountered while trying to validate the context.");
    }
    return array(
      new Type($this->contextDefinition['class']),
    );
  }

  /**
   * Implements \Drupal\Component\Plugin\Context\ContextInterface::validate().
   */
  public function validate() {
    $validator = Validation::createValidatorBuilder()
      ->getValidator();
    return $validator
      ->validateValue($this
      ->getContextValue(), $this
      ->getConstraints());
  }

}