Trigger http update by a rule

Setup, Configuration and Use Scripts & Rules
1

I am using OH3 with the http binding. I use it to send command via an optical interface to by heater.
Unfortunately that fails now and again so I thought I could do a write - read back operation.

like e.g.

I know delays are evil, but the pseudo code of the intended function is:

while ( heaterstatus != "automatic) {
    heater.sendCommand("automatic") 
    heaterstatus.triggerUpdate()
   delay(1000)
}

Is there a way to initiate a http channel update (like triggerUpdate) from a rule ?

2

Just send the right command. :slight_smile:

The while loop is a bad idea though. It can cause the rule to completely stop working.

3

Well, that was pseudo code. The problem is, that the heater sometimes does not receive the command and therefore I need to implement some verification.

Is there something like

Item.triggerUpdate()

?

4

No, there is no triggerUpdate() command, just a sendCommand(). You have to send the command over and over again until it is executed correctly.

a rule for that issue:

var Timer tHeatSwitch = 0
var strHeatCommand = "none"

rule "set heater reliably"
when
    Item heater received command
then
    tHeatSwitch?.cancel
    strHeatCommand = receivedCommand.toString
    tHeatSwitch = createTimer(now.plusSeconds(10),[|
        if(heaterstatus.state.toString != strHeatCommand)
            heater.sendCommand(strHeatCommand)
    ])
end

If command and resulting status are different, you have to incorporate that in an appropriate way, e.g. a hashmap to get the expected status for the received command.

Some additional info:

  • As it’s http, please keep in mind that it takes some time to send and receive. There is a timeout parameter, the timer loop should be at least twice as long as the timeout.
  • This rule will trigger itself, so no need to do it via rescheduling the timer.
  • If done correctly, you will only need one rule for all commands to this item.
  • If you are using more than one of this items, it’s possible to create a rule which will take care of all of them, but it will be way more complex, so if you don’t use a mass of them, just create one rule for each item of that kind.