[feature/system-cron] Reorganized cron task parametrization.

PHPBB3-9596

phpBB/includes/cron/cron_task.php

@@ -48,13 +48,33 @@ interface cron_task
 }
 
 /**
-* Parametrized cron task interface
+* Parametrized cron task interface.
+*
+* Parametrized cron tasks are somewhat of a cross between regular cron tasks and
+* delayed jobs. Whereas regular cron tasks perform some action globally,
+* parametrized cron tasks perform actions on a particular object (or objects).
+* Parametrized cron tasks do not make sense and are not usable without
+* specifying these objects.
+*
 * @package phpBB3
 */
 interface parametrized_cron_task extends cron_task
 {
 	/**
-	* Returns parameters of this cron task as a query string.
+	* Returns parameters of this cron task as an array.
+	*
+	* The array must map string keys to string values.
 	*/
-	public function get_url_query_string();
+	public function get_parameters();
+
+	/**
+	* Parses parameters found in $params, which is an array.
+	*
+	* $params contains user input and must not be trusted.
+	* In normal operation $params contains the same data that was returned by
+	* get_parameters method. However, a malicious user can supply arbitrary
+	* data in $params.
+	* Cron task must validate all keys and values in $params before using them.
+	*/
+	public function parse_parameters($params);
 }