interface ContextDefinitionInterface

interface ContextDefinitionInterface {
    
    /**
     * Gets a human readable label.
     *
     * @return string
     *   The label.
     */
    public function getLabel();
    
    /**
     * Sets the human readable label.
     *
     * @param string $label
     *   The label to set.
     *
     * @return $this
     */
    public function setLabel($label);
    
    /**
     * Gets a human readable description.
     *
     * @return string|null
     *   The description, or NULL if no description is available.
     */
    public function getDescription();
    
    /**
     * Sets the human readable description.
     *
     * @param string|null $description
     *   The description to set.
     *
     * @return $this
     */
    public function setDescription($description);
    
    /**
     * Gets the data type needed by the context.
     *
     * If the context is multiple-valued, this represents the type of each value.
     *
     * @return string
     *   The data type.
     */
    public function getDataType();
    
    /**
     * Sets the data type needed by the context.
     *
     * @param string $data_type
     *   The data type to set.
     *
     * @return $this
     */
    public function setDataType($data_type);
    
    /**
     * Determines whether the data is multi-valued, i.e. a list of data items.
     *
     * @return bool
     *   Whether the data is multi-valued; i.e. a list of data items.
     */
    public function isMultiple();
    
    /**
     * Sets whether the data is multi-valued.
     *
     * @param bool $multiple
     *   (optional) Whether the data is multi-valued. Defaults to TRUE.
     *
     * @return $this
     */
    public function setMultiple($multiple = TRUE);
    
    /**
     * Determines whether the context is required.
     *
     * For required data a non-NULL value is mandatory.
     *
     * @return bool
     *   Whether a data value is required.
     */
    public function isRequired();
    
    /**
     * Sets whether the data is required.
     *
     * @param bool $required
     *   (optional) Whether the data is multi-valued. Defaults to TRUE.
     *
     * @return $this
     */
    public function setRequired($required = TRUE);
    
    /**
     * Gets the default value for this context definition.
     *
     * @return mixed
     *   The default value or NULL if no default value is set.
     */
    public function getDefaultValue();
    
    /**
     * Sets the default data value.
     *
     * @param mixed $default_value
     *   The default value to be set or NULL to remove any default value.
     *
     * @return $this
     */
    public function setDefaultValue($default_value);
    
    /**
     * Gets an array of validation constraints.
     *
     * @return array
     *   An array of validation constraint definitions, keyed by constraint name.
     *   Each constraint definition can be used for instantiating
     *   \Symfony\Component\Validator\Constraint objects.
     */
    public function getConstraints();
    
    /**
     * Sets the array of validation constraints.
     *
     * NOTE: This will override any previously set constraints. In most cases
     * ContextDefinitionInterface::addConstraint() should be used instead.
     *
     * @param array $constraints
     *   The array of constraints.
     *
     * @return $this
     *
     * @see self::addConstraint()
     */
    public function setConstraints(array $constraints);
    
    /**
     * Adds a validation constraint.
     *
     * @param string $constraint_name
     *   The name of the constraint to add, i.e. its plugin id.
     * @param array|null $options
     *   The constraint options as required by the constraint plugin, or NULL.
     *
     * @return $this
     */
    public function addConstraint($constraint_name, $options = NULL);
    
    /**
     * Gets a validation constraint.
     *
     * @param string $constraint_name
     *   The name of the constraint, i.e. its plugin id.
     *
     * @return array
     *   A validation constraint definition which can be used for instantiating a
     *   \Symfony\Component\Validator\Constraint object.
     */
    public function getConstraint($constraint_name);

}