HTTP Binding cannot get value via jsonpath

Add-ons Bindings
1

I want to get the value ETHEUR.last out of here:
https://apiv2.bitcoinaverage.com/indices/global/ticker/short?crypto=ETH&fiat=EUR

the json is:

{
    "ETHEUR": {
        "last": 937.7577893018137,
        "timestamp": 1516477208,
        "averages": {
            "day": 782.0905275642145
        }
    }
}

I tested it here:

And the json-string should be:

$.ETHEUR.last

But this gives me an error

Number nuEthereum "Ethereum: [%.2f °C]" { http="<[http://apiv2.bitcoinaverage.com/indices/global/ticker/short?crypto=ETH&fiat=EUR:60000:JSONPATH($.ETHEUR.last)]" }

2018-01-20 21:03:07.397 [WARN ] [.core.transform.TransformationHelper] - Cannot get service reference for transformation service of type JSONPATH
2018-01-20 21:03:07.397 [WARN ] [ab.binding.http.internal.HttpBinding] - Couldn't transform response because transformationService of type 'JSONPATH' is unavailable

If I use this, I get to much, looks like json does not work

String stEthereum "Ethereum: [%s]" { http="<[https://apiv2.bitcoinaverage.com/indices/global/ticker/short?crypto=ETH&fiat=EUR:60000:JSONPATH($.ETHEUR)]" }

2018-01-20 20:58:39.496 [vent.ItemStateChangedEvent] - stEthereum changed from {
    "ETHEUR": {
        "averages": {
            "day": 782.5499795844371
        },
        "last": 937.8747521049567,
        "timestamp": 1516478252
    }
} to {
    "ETHEUR": {
        "last": 937.7548494130491,
        "timestamp": 1516478309,
        "averages": {
            "day": 782.5760137173403
        }
    }
}

Whatever I do I cannot get the value of last. Any idea what I’m doing wrong?

2

Looks like, the JSONPATH transformation isn’t active?
Did you install it?
in PaperUI:

  • Add-Ons => Transformations => JSONPatch and klick on INSTALL

in files add in addon.cfg type in “jsonpath” (lowercase)

...
# A comma-separated list of transformation services to install (e.g. "map,jsonpath")
transformation = map,jsonpath
...
3

@binderth
Shame on me. That was the problem, I installed it an all is working perfect, thanks.