Union of two groups? Jython Rules for groups

[Mr-JR (James R)]

I’m writing rules in Jython.

I’ve read through the DP for Groups (Thank you @rlkoshak) But I’m not sure how to solve this issue: I have two groups: SecurityGroup_Away and SecurityGroup_Home … Those groups contain sensors and contacts that I care about monitoring if I am Home and the other set if I am Away. There is overlap between the groups. Then I have the Rule:

@rule("Security Check", description="Security alarm for Away and Home setting")
@when("Member of SecurityGroup_Away changed")
@when("Member of SecurityGroup_Home changed")

The problem is: For a particular sensor, I will get a trigger for each Group that contains it, therefore get two triggers in some cases. One solution I was thinking is just to have a group that contains ALL possible sensors that I might care about and have the Rule trigger on changes to that group, then test to see which group that trigger is a member of. Then I can take actions for the Away or Home group.

Is there a better way to do this?

Design Pattern: Working with Groups in Rules

Please see Design Pattern: What is a Design Pattern and How Do I Use Them for how to read and use DPs. Problem Statement Often one finds a number of Rules that are very similar and that all work on similar Items resulting in a lot of duplicated code. One way to solve this problem is through the use of Groups. Concept [image] This DP is not a standard DP in that it provides a single concrete template to follow to solve a specific problem. Instead this DP is more of a grand exploration of some …

[Mr-JR (James R)]

I guess the other obvious way is to simply split it into two rules, then check which mode I’m in… should have thought about the problem longer before posting.

[rlkoshak (Rich Koshak)]

Other ideas:

• Set a timer for half a second or so for a given Item that has triggered the rule. When the rule triggers and a timer exists, exit. That will cause the rule to ignore the second trigger.

• Just have one Group and dynamically adjust the membership of that Group when you change from home to away. However, this approach has a limitation that the Rule itself will have to be reloaded because a Member of trigger unrolls to a separate trigger for each member of the Group at load time. I’ve an openhab-rules-tools library that shows how to do that but it’s written for OH 2.5 and I don’t yet know if it will work for OH 2.x. I’ve not been able to update my Python libraries for 3.x yet.

• You don’t say what the rule does. Maybe it can be constructed such that it doesn’t matter if it runs twice.

[Mr-JR (James R)]

Thanks those are good suggestions too … I hadn’t thought about dynamically adjusting the list, I’ll take a look at what you wrote.

@rlkoshak

You don’t say what the rule does. Maybe it can be constructed such that it doesn’t matter if it runs twice.

Ultimately the rule sends a notification to my Telegram account and/or sets an in-house alarm … it was getting two back to back notifications that was undesired.

[rlkoshak (Rich Koshak)]

@Mr-JR

it was getting two back to back notifications that was undesired.

Sounds like a job for rate limiting. Unfortunately the Python version of that library still uses Joda DateTime and will need modifications to work in OH 3. I’ll happily accept PRs though. But I’d like to maintain OH 2.x compatibility which makes it a little trickier than just replacing Joda DateTime with ZonedDateTime.

I use that library for things like low battery alerts or “fill the humidifier” alerts so they only get sent once a day. But it supports times from milliseconds to days.

[Mr-JR (James R)]

@rlkoshak

Sounds like a job for rate limiting.

Bingo, there will be other cases where I will/might get multiple triggers for the same class events in some period of time.