When the state changes the change event is triggered 3 times

[felipelerena]

I have not much else to add

this will trigger the change event 3 times

[Vantive1]

I have had the same problem. State changes producing multiple (3) output messages. After I changed the "History" setting, i.e. the number of states to keep, and then did a re-deploy, the issue disappeared. Now I can't reproduce the problem.

[Vantive1]

Now the problem is back again, changing history setting wasn't a permanent workaround. Please have a look at this problem, thanks!

[youzer-name]

Seeing the same issue. It seems like each time I redeploy, the number of messages increases. Changing the history number seems to fix it, as did changing the name of the state variable. It seems like editing anything about the variable fixes it, but I haven't figure out yet what initially causes the problem, other than it seems to happen after I redeploy. I had to resort to putting a throttle node after one of my states to avoid duplicate messages.

[youzer-name]

I tried to look at the source code for this node, but I really don't understand what's going on under the hood so I'm afraid I'm not going to be able to contribute a fix for this issue. I can only offer up some observations that might help someone else find the source of the issue.

The trigger for the duplicate messages appears to be changing the "Fire On" setting of the getState Node from "initializing" to either "state change" or "both". Each time this setting is changed and the node is redeployed, an additional duplicate message gets added. Changing back to "initializing" doesn't add a duplicate. Changing from initializing to either of the other two options, or changing from "state change" to "both" (or vice-versa) adds another duplicate message.

The issue only affects the specific getState node that is being updated. A second getState node looking at the same state variable in the same flow will continue to work normally while the other flow outputs 2 or more messages per state change.

Restarting Node Red fixes the duplicate messages.

The only other way to fix the affected node is to click the edit button to go to the settings of the state variable config node and save some edit to the config. Changing the name, the label, or the history setting all fixed the issue. I also tested going into the variable config editor from a different node that wasn't outputting multiple messages. Editing the variable from that other node and redeploying only changed nodes also worked.

So the issue seems to be related to what happens when you select either "State change" or "Both" as the Fire On setting of a specific node. It doesn't affect other nodes using the same variable, and it can be fixed by making changes to the variable config.

Again, I tried to trace the code to see what's being done when the user makes those selections, but I don't have enough experience with Javascript to figure it out. In the meantime, I've placed a 100ms Throttle node after every getState node in my flows so I don't have to worry about duplicate messages. That's a bit of an ugly workaround, so I'm hoping someone can find the source of the issue and contribute a fix to this project.