Hi everyone.
As some of you, I was missing the mqtt eventbus feature in MQTTv2, so after reading across the forums and encountering quite some errors I finally managed to mimic the eventbus feature by using rules.
I thought I would share this. I’m not a script or rule guru, so I’m sure this can be optimised.
In PaperUI I created:
MQTT broker: mqtt:broker:8ca384dd
Publish Trigger channel: mqtt:broker:8ca384dd:pub
The Publish Trigger listens to everything (#) and the delimiter is “#”.
a Group item dg_AllItems
my mqqteventbus.rules
import org.eclipse.smarthome.model.script.ScriptServiceUtil
// MQTT naming convention i use:
//
//commandPublishTopic = /openHAB/out/${item}/command
//stateSubscribeTopic = /openHAB/in/${item}/state
// MASTER
var boolean commandSubscribeTopic = false
var boolean stateSubscribeTopic = true
var boolean statePublishTopic = false
var boolean commandPublishTopic = true
// SLAVE
// var boolean commandSubscribeTopic = true
// var boolean stateSubscribeTopic = false
// var boolean statePublishTopic = true
// var boolean commandPublishTopic = false
// We need a group with all items as a Member of trigger.
// Creating one dynamicly. (Group dg_AllItems)
// ScriptServiceUtil.getItemRegistry.getItems() can not be used as a Member of trigger (I've tried :-)
rule "populate dynamic group dg_AllItems"
when
Time cron "0 0/1 * * * ?"
then
// add all items to the group
ScriptServiceUtil.getItemRegistry.getItems().forEach[item | dg_AllItems.addMember(item) ]
// remove all items which no longer exist
dg_AllItems.members.filter(s | ScriptServiceUtil.getItemRegistry.getItems().filter[i | i.name.contains(s.name)].length == 0).forEach[item | dg_AllItems.removeMember(item)]
// remove the group from itself (odd.)
dg_AllItems.removeMember(dg_AllItems)
//DEBUG dg_AllItems.members.forEach[ item | logInfo("dg_AllItems_member",item.name) ]
end
rule "Publish command to broker"
when
Member of dg_AllItems received command
then
if (commandPublishTopic){
val actions = getActions("mqtt","mqtt:broker:8ca384dd")
actions.publishMQTT("/openHAB/out/"+triggeringItem.name+"/command",receivedCommand.toString)
}
end
rule "Publish state to broker"
when
Member of dg_AllItems changed
then
if (statePublishTopic){
val actions = getActions("mqtt","mqtt:broker:8ca384dd")
actions.publishMQTT("/openHAB/in/"+triggeringItem.name+"/state",triggeringItem.state.toString)
}
end
rule "Subscribe to broker"
when
Channel "mqtt:broker:8ca384dd:pub" triggered
then
var evnt_payload = receivedEvent.getEvent.toString.split("#")
var mqtttopic = evnt_payload.get(0).toString.split("/")
var mqttcommand = evnt_payload.get(1)
var mqttitem = mqtttopic.get(mqtttopic.length-2)
var mqttcommandorstate = mqtttopic.get(mqtttopic.length-1)
var ItemExists = dg_AllItems.members.filter[item | item.name.contains(mqttitem)].length
if (ItemExists > 0){
if (commandSubscribeTopic && mqttcommandorstate == "command") {
sendCommand(mqttitem,mqttcommand)
}
else {
if (stateSubscribeTopic && mqttcommandorstate == "state") {
postUpdate(mqttitem,mqttcommand)
}
}
}
end
The Time cron rule is only there because I didn’t want to add each Item to the group manually, so updating the group every minute is a bit of an overkill. Of course you could always use a specific “Eventbus” group to control which items are used or not.
225 x Active x 80 x 1.2.0 x Paho MQTT Client
226 x Active x 80 x 0.10.0.oh240 x Eclipse SmartHome MQTT Binding
227 x Active x 80 x 0.10.0.oh240 x Eclipse SmartHome MQTT Thing Binding
228 x Active x 80 x 0.10.0.oh240 x Eclipse SmartHome MQTT Transport Bundle
About that Publish Trigger Channel. From my understanding this is needed to react on published messages on the broker. But I need to publish to the broker…
Didn’t try that one.
But other items created via paperUI are working correctly.
I’m able to receive and publish messages with these items, it’s just the rule that gives me problems.
So there is nothing wrong with the broker itself.
For some reason it’s working now.
Unfortunatly I’m unable to pinpoint where it went wrong.
When I output the ‘actions’ variable to the console (logInfo) it still gives me a null value, but the broker is receiving messages.
The only difference is that I removed whitespaces before and after the equation mark, and I created a new broker connection (for testing) in PaperUI.
Now both of the broker connections are working.
Thanks for the help.
Sorry, but can you or @vzorglub please explain why the actions variable needs to be declared globally? As a programmer I would consider the declaration in the if blocks cleaner and would want to avoid global variables whereever possible.
There’s an error in the “Publish state to broker” rule. There’s no such thing as “receivedCommand” in the case of a member changing. What you need to do is “triggeringItem.state.toString()” instead. Maybe you want to update your code.
For those who want to stick closer to the original publish/subscribe topics of the old evenbus (for example because your master or client is not openhab). Check the eventbus.cfg file for the original topics. Change the “publish to xxx” rules accordingly and instead in the subscribe “Subscribe to broker” rule change line “var mqttcommandorstate = mqtttopic.get(mqtttopic.length-1)” to “var mqttcommandorstate = mqtttopic.get(2)”
With these simply modifications I could re-use my old master which is a HomeControl Android App where I didn’t want to remap hundreds of mqtt paths
This rule works perfectly. I would like to extend it with a system start so that all values of the items are sent when the system starts up. Is this possible?
You shouldn’t need to. The rule will trigger when items change value regardless. That will happen at start-up to
You could add a trigger to the group building rule:
rule "populate dynamic group dg_AllItems"
when
Time cron "0 0/1 * * * ?" or
System started
then
// add all items to the group
ScriptServiceUtil.getItemRegistry.getItems().forEach[item | dg_AllItems.addMember(item) ]
// remove all items which no longer exist
dg_AllItems.members.filter(s | ScriptServiceUtil.getItemRegistry.getItems().filter[i | i.name.contains(s.name)].length == 0).forEach[item | dg_AllItems.removeMember(item)]
// remove the group from itself (odd.)
dg_AllItems.removeMember(dg_AllItems)
//DEBUG dg_AllItems.members.forEach[ item | logInfo("dg_AllItems_member",item.name) ]
end
