[request] Statefull triggers

📐 Rule Machine®
1

It would be really nice to have trigger conditions that remember the previous state of the trigger value, and can trigger a rule when a threshold is crossed.

For example, I currently have rules to open and close my blinds when the illuminance reading on a sensor goes above or below a given threshold:

LivingRoomBlindsRule
LivingRoomBlindsRule.png1317×1156 115 KB

Currently, the only trigger that works is to trigger the rule every time the illuminance reading changes. Since the sensor reports every 5 minutes, this means that the rule runs every 5 minutes. To get the behavior I want I have to keep track of the previous illuminance value in a variable.

It would be very convenient if I could define triggers like "Illuminance of Upstairs Window Multisensor rises above 400" and "Illuminance of Upstairs Window Multisensor drops below 400" so I don't have to keep track of the previous reading explicitly within the rule logic.

2

Maybe I'm not understanding you. Why can't you use those as triggers?

12%20PM

When you press Done, this is what the trigger looks like. Isn't this what you want?

17%20PM

3

As far as I can tell, "becomes" is just bad wording on those triggers. It's really "is". The rule will trigger each time the sensor reports a value as long as that value is greater than the target. That's not what I want. I want it to trigger once, when the value transitions from less than the target to greater, and not trigger again until the value drops back below the target.

4

The Illuminance device IS sending a report. Every 5 mins. Hiding the compare doesn't change the work the hub has to do. You do it in the Rule or the Hub does it 'under the covers' -- I don't see what is gained by burying the event handing.

1 Like
5

You can use a Private Boolean in the rule to ensure it fires only once when Illuminance > 400

Trigger Rule 1:

Illuminance > 400

Actions Rule 1:

IF Private Boolean False: Exit Rule
IF (Illuminance > 400) THEN
    Set Private Boolean False
    Do Stuff
END-IF

Trigger Rule 2:

Illuminance < 400

Actions Rule 2:

Set Private Boolean True for Rule 1
6

@csteele It doesn't change the work the hub has to do. I picked a simple example, but I have rules where hiding the state in the trigger would make them much easier to read and reason about.

@aaiyar That's fairly similar to the private variable approach I'm using. The early-return is a bit nicer than the if conditions I have though.

7

Except it doesn't need to keep track of the previous illuminance using a variable. So even though it is broken into two rules, it should be faster.

1 Like