class Context in Drupal 8

A generic context class for wrapping data a plugin needs to operate.

Hierarchy

• class \Drupal\Component\Plugin\Context\Context implements ContextInterface

3 files declare their use of Context

Context.php in core/lib/Drupal/Core/Plugin/Context/Context.php

ContextAwarePluginBase.php in core/lib/Drupal/Component/Plugin/ContextAwarePluginBase.php

ContextTest.php in core/tests/Drupal/Tests/Component/Plugin/Context/ContextTest.php

3 string references to 'Context'

Page::buildOptionsForm in core/modules/views/src/Plugin/views/display/Page.php

Provide a form to edit options for this plugin.

system.schema.yml in core/modules/system/config/schema/system.schema.yml

core/modules/system/config/schema/system.schema.yml

views.display.schema.yml in core/modules/views/config/schema/views.display.schema.yml

core/modules/views/config/schema/views.display.schema.yml

File

core/lib/Drupal/Component/Plugin/Context/Context.php, line 12

Namespace

Drupal\Component\Plugin\Context

class Context implements ContextInterface {

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

  /**
   * The definition to which a context must conform.
   *
   * @var \Drupal\Component\Plugin\Context\ContextDefinitionInterface
   */
  protected $contextDefinition;

  /**
   * Create a context object.
   *
   * @param \Drupal\Component\Plugin\Context\ContextDefinitionInterface $context_definition
   *   The context definition.
   * @param mixed|null $context_value
   *   The value of the context.
   */
  public function __construct(ContextDefinitionInterface $context_definition, $context_value = NULL) {
    $this->contextDefinition = $context_definition;
    $this->contextValue = $context_value;
  }

  /**
   * {@inheritdoc}
   */
  public function getContextValue() {

    // Support optional contexts.
    if (!isset($this->contextValue)) {
      $definition = $this
        ->getContextDefinition();
      $default_value = $definition
        ->getDefaultValue();
      if (!isset($default_value) && $definition
        ->isRequired()) {
        $type = $definition
          ->getDataType();
        throw new ContextException(sprintf("The %s context is required and not present.", $type));
      }

      // Keep the default value here so that subsequent calls don't have to look
      // it up again.
      $this->contextValue = $default_value;
    }
    return $this->contextValue;
  }

  /**
   * {@inheritdoc}
   */
  public function hasContextValue() {
    return (bool) $this->contextValue || (bool) $this
      ->getContextDefinition()
      ->getDefaultValue();
  }

  /**
   * {@inheritdoc}
   */
  public function getContextDefinition() {
    return $this->contextDefinition;
  }

  /**
   * {@inheritdoc}
   */
  public function getConstraints() {
    if (empty($this->contextDefinition['class'])) {
      throw new ContextException("An error was encountered while trying to validate the context.");
    }
    return [
      new Type($this->contextDefinition['class']),
    ];
  }

  /**
   * {@inheritdoc}
   */
  public function validate() {
    $validator = Validation::createValidatorBuilder()
      ->getValidator();
    return $validator
      ->validateValue($this
      ->getContextValue(), $this
      ->getConstraints());
  }

}

Members

Name	Modifiers	Type	Description	Overrides
Context::$contextDefinition	protected	property	The definition to which a context must conform.	1
Context::$contextValue	protected	property	The value of the context.
Context::getConstraints	public	function	Gets a list of validation constraints. Overrides ContextInterface::getConstraints	1
Context::getContextDefinition	public	function	Gets the provided definition that the context must conform to. Overrides ContextInterface::getContextDefinition	1
Context::getContextValue	public	function	Gets the context value. Overrides ContextInterface::getContextValue	1
Context::hasContextValue	public	function	Returns whether the context has a value. Overrides ContextInterface::hasContextValue	1
Context::validate	public	function	Validates the set context value. Overrides ContextInterface::validate	1
Context::__construct	public	function	Create a context object.	1