Everywhere we would need the language/parent_id we already have it available by loading the associated rule. Storing the language/parent from user input and using that is a bit of a bad practice as it could lead to problems (imagine that the user input doesn't match what the rule has). With the current code there really wouldn't be a major problem (it's just for the URL and is fine in u_action), but when things like that are done on a larger scale you can accidentally create major problems and even security breaches. We don't want the language/parent used for anything except the u_action as it could cause problems, so we don't want to make them available easily (where someone could use the variable without being careful and knowing where that data is from).