JSONPATH transform help

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1

If have trouble getting the state to update to item from mqtt.
topic from mqtt is : '{“state”:“OFF”,“color”:null}

On the thing configuration of a Generic MQTT, i enter the following at the Incoming Value Transformations:
“JSONPATH:$.state”

But that result in the following error
2023-05-05 16:43:37.269 [WARN ] [t.generic.ChannelStateTransformation] - Transformation service “JSONPATH for pattern $.state” not found!
2023-05-05 16:43:37.269 [WARN ] [ab.binding.mqtt.generic.ChannelState] - Command ‘{“state”:“OFF”,“color”:null}’ from channel ‘mqtt:topic:2613cfa615:89551dcf62:state’ not supported by type ‘OnOffValue’: No enum constant org.openhab.core.library.types.OnOffType.{“state”:“OFF”,“color”:null}

I have the same with the brightnes of a light
2023-05-05 16:29:52.360 [WARN ] [t.generic.ChannelStateTransformation] - Transformation service “JSONPATH for pattern $[brightness”] not found!
2023-05-05 16:29:52.360 [WARN ] [ab.binding.mqtt.generic.ChannelState] - Command ‘{“brightness”:100,“color”:null}’ from channel ‘mqtt:topic:2613cfa615:89551dcf62:brightness’ not supported by type ‘PercentageValue’: Unknown String!

i tested the jsonpath with online validators and those ‘find’ the state or brightness.

2

JSONpath transform is not installed by default. Have you installed it? (Settings → Bindings then under the Others tab).

3

Thank you for the quick reply, but i do have JSONPath transformation installed. Runing OH 3.3 by the way.

4

Well, the problem is not your actual path string. As you point out, that works in an outside test. The error message is pretty unambiguous, your JSONpath transform cannot be found by OH. The subsequent errors just occur because the untransformed value is not valid when then passed by the channel to the item.

This means either the transform is not installed or at least something has happened to break its install, or your reference to it is incorrect in your configuration. If you’re sure the transform binding is working properly (i.e., it works in some other context on your system), then you’ll have to actually show us the exact configuration you’re using.

5

I uninstalled jsonpath, restarted openhab and then installed. Now it works fine. Thank you for pointing to a broken installation of my jsonpath. I did not use it anywhere else on my system.