Rule when a value changed


is there a possibility to create a rule which checks for changing values of a thing? I read the documentation and searched but cannot find a solution.

I have following code:

[code]QStatus is a kind of value.
QStatus are queued, begun, won and lost.

Quest is a kind of thing.
Quest has a QStatus called QuestStatus.
QuestStatus of Quest is usually queued.
Quest has a Text called beginning.
Quest has a Text called ending happily.
Quest has a Text called ending badly.[/code]

Now I want to create a rule that fires when the status of a quest changes from queued to begun. This rule should display the text of the property beginning. So if I change the status of a quest the beginning text should be displayed automatically by the rule.


You could write a phrase “begin (Q - quest)” and then always use that to set the status.

You could use scenes for this, and write “when [scene] begins” and “when [scene] ends [adverb]” rules.