OH3 error in rule to show me "time since last state update"

Setup, Configuration and Use Scripts & Rules
1

Hi,
i have a sitemap where i can see, how long in minutes the last update of an item was ago.

So with cron i get a new calculation every minute and i can see: last update: 5 minutes, 6 minutes and so on

Here is my rule:

rule "Update Xiaomi Temp time since"
when
    Time cron "0 * * * * ?"
then
	if(SystemStarting.state == OFF) {
	gXiaomiZeit.members.forEach[ DateTimeItem lastTime |
	logInfo("temp-anz-5 rule","lastTime : "+lastTime)
		val lastMillis = (lastTime.state as DateTimeType).getZonedDateTime().toInstant().toEpochMilli()
        val mins = (now.toInstant().toEpochMilli() - lastMillis) / 60000
        //val split = lastTime.split("_") // so we can reconstruct the time_since Item name
		val split = lastTime.name.split('_')
        (split.get(0)+"_"+split.get(1)+"_"+split.get(2)+"_time_since").postUpdate(mins.toString)
    ]
	}
end

loginfo output and error in openhab log:

2022-12-20 14:32:00.519 [INFO ] [ab.core.model.script.temp-anz-5 rule] - lastTime : Xiaomi_Temp_1_last_connection (Type=DateTimeItem, State=NULL, Label=Temp 1, Category=clock, Groups=[gXiaomiZeit])

2022-12-20 14:32:00.520 [ERROR] [internal.handler.ScriptActionHandler] - Script execution of rule with UID 'temperatur_anzeigen-5' failed: Could not cast NULL to org.openhab.core.library.types.DateTimeType; line 100, column 21, length 30 in temperatur_anzeigen

2022-12-20 14:32:06.520 [WARN ] [b.core.model.script.actions.BusEvent] - Cannot convert '2022-12-20T14:32:06.520505+01:00[Europe/Berlin]' to a state type which item 'Xiaomi_Temp_10_last_connection' accepts: [DateTimeType, UnDefType].

Any ideas how to solve this?

Do you need more information?

2

Now I understand it! :slight_smile: :slight_smile:

As I said before, you need to check whether lastTime.state is a DateTimeType before casting it.

Maybe something like this:

gXiaomiZeit.members.forEach[ DateTimeItem lastTime |
    var status = ""
    if (lastTime.state instanceof DateTimeType) {
      val lastMillis = (lastTime.state as DateTimeType).getZonedDateTime().toInstant().toEpochMilli()
      val mins = (now.toInstant().toEpochMilli() - lastMillis) / 60000
      status = mins.toString
    }
    val split = lastTime.name.split('_')
    (split.get(0)+"_"+split.get(1)+"_"+split.get(2)+"_time_since").postUpdate(status)
]
}

Updated… I REALLY hate rulesdsl now… so tedious

3

And using Duration

val mins = java.time.Duration.between(now, (lastTime.state as DateTimeType).zonedDateTime).toMinutes

How does this work? Is that something new added to the language? It should be:

postUpdate(split.get(0)+"_"+split.get(1)+"_"+split.get(2)+"_time_since", mins)

You don’t show your Item naming pattern but I bet something like: lastTime.name.replace('sensor', 'time_since') would make more sense here than splitting and reassembling the name like this.

1 Like
4

That rule worked for years with OH2.

And my naming can be seen in the Log-Output.

I have Xiaomi Zigbee Temperature Sensors.

Items:
number: Xiaomi_Temp_1
datetime: Xiaomi_Temp_1_last_connection

By the way… With the new rule errors are gone, but now i get warnings:

2022-12-21 14:27:01.471 [WARN ] [b.core.model.script.actions.BusEvent] - Cannot convert '' to a state type which item 'Xiaomi_Temp_1_time_since' accepts: [DecimalType, QuantityType, UnDefType].

It seems, that i get no value to my datetime item. I will wait some time until the Temp Sensors give me new values.

5

This did not ever work in OH2.

Maybe your Item got updated by some other method that you’ve overlooked - another rule, a timestamp profile, say.

6

Ahh your “time_since” item is a Numeric item! I thought it was a String item.

If I were you I would either change it to a DateTime item (and do the formatting of time / duration using state description format thingy), or a String. But assuming you want to keep things as is, what would you want the “time_since” to be updated to, if the lastTime is NULL? That’s what you need to do in the “else” clause.

GOOD catch! I didn’t even pay attention to that!

Incorporating the excellent suggestions from @rlkoshak:

gXiaomiZeit.members.forEach[ DateTimeItem lastTime |
    val timeSinceItemName = lastTime.name.replace('sensor', 'time_since')
    if (lastTime.state instanceof DateTimeType) {
      val mins = java.time.Duration.between((lastTime.state as DateTimeType).zonedDateTime, now).toMinutes
      postUpdate(timeSinceItemName, mins.toString)
    } else {
      postUpdate(timeSinceItemName, NULL)
    }
]

Note I switched the order for Duration.between. I think it should be Duration.between(older, newer) to get a positive duration. See Duration (Java Platform SE 8 )

1 Like