interface ExecutionStateInterface

interface ExecutionStateInterface {
    
    /**
     * Sets a state variable based on its definition and value.
     *
     * @param string $name
     *   The context variable name.
     * @param \Drupal\rules\Context\ContextDefinitionInterface $definition
     *   The context definition of the variable.
     * @param mixed $value
     *   The variable value.
     *
     * @return $this
     */
    public function setVariable($name, ContextDefinitionInterface $definition, $value);
    
    /**
     * Sets a state variable with some typed data object.
     *
     * @param string $name
     *   The variable name.
     * @param \Drupal\Core\TypedData\TypedDataInterface $data
     *   The variable wrapped as typed data.
     *
     * @return $this
     */
    public function setVariableData($name, TypedDataInterface $data);
    
    /**
     * Gets a variable.
     *
     * @param string $name
     *   The name of the variable to return.
     *
     * @return \Drupal\Core\TypedData\TypedDataInterface
     *   The variable wrapped as typed data.
     *
     * @throws \Drupal\rules\Exception\EvaluationException
     *   Throws an EvaluationException if the variable does not exist in the
     *   state.
     */
    public function getVariable($name);
    
    /**
     * Gets the value of a variable.
     *
     * @param string $name
     *   The name of the variable to return the value for.
     *
     * @return mixed
     *   The variable value.
     *
     * @throws \Drupal\rules\Exception\EvaluationException
     *   Throws an EvaluationException if the variable does not exist in the
     *   state.
     */
    public function getVariableValue($name);
    
    /**
     * Checks if a variable exists by name in the execution state.
     *
     * @param string $name
     *   The variable name.
     *
     * @return bool
     *   TRUE if the variable exists, FALSE otherwise.
     */
    public function hasVariable($name);
    
    /**
     * Removes a variable from the state if it is set.
     *
     * @param string $name
     *   The name of the variable to remove.
     *
     * @return $this
     */
    public function removeVariable($name);
    
    /**
     * Returns a value as specified in the selector.
     *
     * @param string $property_path
     *   The property path string starting with a variable name; e.g.,
     *   "node.uid.entity.mail.value".
     * @param string $langcode
     *   (optional) The language code used to get the argument value if the
     *   argument value should be translated. Defaults to NULL.
     *
     * @return \Drupal\Core\TypedData\TypedDataInterface
     *   The variable wrapped as typed data.
     *
     * @throws \Drupal\rules\Exception\EvaluationException
     *   Throws an EvaluationException in case the selector cannot be applied.
     */
    public function fetchDataByPropertyPath($property_path, $langcode = NULL);
    
    /**
     * Mark a variable to be saved later when the execution is finished.
     *
     * @param string $selector
     *   The data selector that specifies the target object to be saved. Example:
     *   node.uid.entity.
     *
     * @return $this
     */
    public function saveChangesLater($selector);
    
    /**
     * Returns the list of variables that should be auto-saved after execution.
     *
     * @return string[]
     *   The list of data selectors that specify the target object to be saved.
     *   Example: node.uid.entity.
     */
    public function getAutoSaveSelectors();
    
    /**
     * Saves all variables that have been marked for auto saving.
     *
     * @return $this
     */
    public function autoSave();

}