JSON transform problem in OH 2.3

[Michal_Szymanski]

When I migratete to OH 2.3 problem wit JSON transform appeared:

forecastJson="{\"cod\":\"200\",\"message\":0.0025,\"cnt\":8,\"list\":[{\"dt\":1534572000,\"main\":{\"temp\":18.32,\"temp_min\":18.32,\"temp_max\":19.62,\"pressure\":1021.48,\"sea_level\":1031.67,\"grnd_level\":1021.48,\"humidity\":83,\"temp_kf\":-1.31},\"weather\":[{\"id\":803,\"main\":\"Clouds\",\"description\":\"broken clouds\",\"icon\":\"04d\"}],\"clouds\":{\"all\":68},\"wind\":{\"speed\":2.71,\"deg\":337.008},\"sys\":{\"pod\":\"d\"},\"dt_txt\":\"2018-08-18 06:00:00\"},{\"dt\":1534582800,\"main\":{\"temp\":22.64,\"temp_min\":22.64,\"temp_max\":23.51,\"pressure\":1022.21,\"sea_level\":1032.39,\"grnd_level\":1022.21,\"humidity\":74,\"temp_kf\":-0.87},\"weather\":[{\"id\":801,\"main\":\"Clouds\",\"description\":\"few clouds\",\"icon\":\"02d\"}],\"clouds\":{\"all\":24},\"wind\":{\"speed\":3.02,\"deg\":354.507},\"sys\":{\"pod\":\"d\"},\"dt_txt\":\"2018-08-18 09:00:00\"},{\"dt\":1534593600,\"main\":{\"temp\":24.32,\"temp_min\":24.32,\"temp_max\":24.76,\"pressure\":1022.01,\"sea_level\":1032.15,\"grnd_level\":1022.01,\"humidity\":74,\"temp_kf\":-0.44},\"weather\":[{\"id\":500,\"main\":\"Rain\",\"description\":\"light rain\",\"icon\":\"10d\"}],\"clouds\":{\"all\":20},\"wind\":{\"speed\":2.51,\"deg\":350.5},\"rain\":{\"3h\":0.495},\"sys\":{\"pod\":\"d\"},\"dt_txt\":\"2018-08-18 12:00:00\"},{\"dt\":1534604400,\"main\":{\"temp\":24.38,\"temp_min\":24.38,\"temp_max\":24.38,\"pressure\":1021.82,\"sea_level\":1032.09,\"grnd_level\":1021.82,\"humidity\":66,\"temp_kf\":0},\"weather\":[{\"id\":500,\"main\":\"Rain\",\"description\":\"light rain\",\"icon\":\"10d\"}],\"clouds\":{\"all\":0},\"wind\":{\"speed\":3.06,\"deg\":348.503},\"rain\":{\"3h\":2.1},\"sys\":{\"pod\":\"d\"},\"dt_txt\":\"2018-08-18 15:00:00\"},{\"dt\":1534615200,\"main\":{\"temp\":21.07,\"temp_min\":21.07,\"temp_max\":21.07,\"pressure\":1021.97,\"sea_level\":1032.35,\"grnd_level\":1021.97,\"humidity\":56,\"temp_kf\":0},\"weather\":[{\"id\":800,\"main\":\"Clear\",\"description\":\"clear sky\",\"icon\":\"01d\"}],\"clouds\":{\"all\":0},\"wind\":{\"speed\":2.81,\"deg\":325.002},\"rain\":{},\"sys\":{\"pod\":\"d\"},\"dt_txt\":\"2018-08-18 18:00:00\"},{\"dt\":1534626000,\"main\":{\"temp\":15.67,\"temp_min\":15.67,\"temp_max\":15.67,\"pressure\":1023.38,\"sea_level\":1033.67,\"grnd_level\":1023.38,\"humidity\":68,\"temp_kf\":0},\"weather\":[{\"id\":800,\"main\":\"Clear\",\"description\":\"clear sky\",\"icon\":\"01n\"}],\"clouds\":{\"all\":0},\"wind\":{\"speed\":2.56,\"deg\":333.501},\"rain\":{},\"sys\":{\"pod\":\"n\"},\"dt_txt\":\"2018-08-18 21:00:00\"},{\"dt\":1534636800,\"main\":{\"temp\":12.21,\"temp_min\":12.21,\"temp_max\":12.21,\"pressure\":1023.52,\"sea_level\":1033.85,\"grnd_level\":1023.52,\"humidity\":89,\"temp_kf\":0},\"weather\":[{\"id\":800,\"main\":\"Clear\",\"description\":\"clear sky\",\"icon\":\"01n\"}],\"clouds\":{\"all\":0},\"wind\":{\"speed\":1.28,\"deg\":157.002},\"rain\":{},\"sys\":{\"pod\":\"n\"},\"dt_txt\":\"2018-08-19 00:00:00\"},{\"dt\":1534647600,\"main\":{\"temp\":11.15,\"temp_min\":11.15,\"temp_max\":11.15,\"pressure\":1023,\"sea_level\":1033.33,\"grnd_level\":1023,\"humidity\":87,\"temp_kf\":0},\"weather\":[{\"id\":800,\"main\":\"Clear\",\"description\":\"clear sky\",\"icon\":\"01n\"}],\"clouds\":{\"all\":0},\"wind\":{\"speed\":1.72,\"deg\":177.001},\"rain\":{},\"sys\":{\"pod\":\"n\"},\"dt_txt\":\"2018-08-19 03:00:00\"}],\"city\":{\"id\":3092909,\"name\":\"Lublewo Gdanskie\",\"coord\":{\"lat\":54.2846,\"lon\":18.5039},\"country\":\"PL\"}}"
var String[] rainValues  = transform("JSONPATH","$.list[*].rain.3h", forecastJson).replace("[", "").replace("]", "").split(",") 

returned:
JsonPath expressions with more than one result are not allowed, please adapt your selector.

I found such thread:

JSONPATH Transformation Service vs. JSONPATH

Purpose Explain recent history of the functionality, along with faults Describe a breaking change that is committed to ESH and is currently in the OH 2.3.0 snapshot Describe what I have proposed in the issue that the breaking PR was trying to resolve My current workaround History of functionlity from OH 2.0.0 to OH 2.3.0 snapshot 1194 (January 23) [approximately] The JSONPATH Transformation Service uses Jayway JSONPATH. When the path is definite, JSONPATH returns a string value, and the JSON…

but still I do not know how to change my code

[Udo_Hartmann]

Well, you are trying to create a string list and that’s not possible any more. You have to select a single value for JSON transformation.

[job (Joachim Boeddeker)]

I switched to the jq executable. If you are on linux this is easy. Instead of http binding and jsonpath transformation i now use exec binding with curl and jq.

jq - commandline JSON processor [version 1.5-1-a5b5cbe]
Usage: jq [options] <jq filter> [file...]

        jq is a tool for processing JSON inputs, applying the
        given filter to its JSON text inputs and producing the
        filter's results as JSON on standard output.
        The simplest filter is ., which is the identity filter,
        copying jq's input to its output unmodified (except for
        formatting).
        For more advanced filters see the jq(1) manpage ("man jq")
        and/or https://stedolan.github.io/jq

[vzorglub (Vincent Regaud)]

You could use a js transform to return a string with the values split by ,
and then use a string.split(",").get(*) to assign to the different items:

rainvalues.js

(function(datastring) {
var data = JSON.parse(datastring);
var listValues = data.list;
var text = "";
var i;
for (i = 0; i < listValues.length; i++) {
    if (listValues[i].hasOwnProperty('rain')) {
        if (listValues[i].rain['3h'] !== undefined) {
            text = text + listValues[i].rain['3h'].toString() + ",";
        }
    }
}
text = text.substring(0, text.length-1);
return text;
})(input)

In your rule:

var String rainValues  = transform("JS","$.list[*].rain.3h", rainvalues.js)
item1.postUpdate(rainValues.split(",").get(0))
item2.postUpdate(rainValues.split(",").get(1))
...

The only issue is that you don’t know how many rainValues you are going to get

[5iver (Scott Rushworth)]

If you’d like to use jq, this filter will work return exactly what the JSONPATH did…

[.list[].rain."3h" | numbers]

[Michal_Szymanski]

@vzorglub

var String rainValues = transform(“JS”,“$.list[*].rain.3h”, rainvalues.js)

When I try it I’ve got:

2018-08-20 12:25:01.278 [ERROR] [ntime.internal.engine.ExecuteRuleJob] - Error during the execution of rule 'Wtr_algorithm': The name 'rainvalues' cannot be resolved to an item or type; line 400, column 65, length 10

In my code:

var String rainValuesStr  = transform("JS","$.list[*].rain.3h", rainvalues.js)
logInfo( "FILE", "Wtr_algorithm: rainValuesStr [" + rainValuesStr +  "]")

and I’ve added js file to ‘transform’ directory.

Michal

[vzorglub (Vincent Regaud)]

My fault.
Put rain values.js in “”

[Michal_Szymanski]

When you use “” it will be treated as a string that should be converted.

Michal

[Michal_Szymanski]

How do you execute jq from OH? Using Exec binding?

[vzorglub (Vincent Regaud)]

I got it the wrong way around:

var String rainValues = transform("JS", "rainvalues.js", forecastJson)

[5iver (Scott Rushworth)]

@Michal_Szymanski

How do you execute jq from OH? Using Exec binding?

I use it with executeCommandLine. There is an example in the post you linked to in the OP, which also includes getting the data through curl. This may work for you…

import java.util.List
...
val String forecastJson="{\"cod\":\"200\",\"message\":0.0025,\"cnt\":8,\"list\":[{\"dt\":1534572000,\"main\":{\"temp\":18.32,\"temp_min\":18.32,\"temp_max\":19.62,\"pressure\":1021.48,\"sea_level\":1031.67,\"grnd_level\":1021.48,\"humidity\":83,\"temp_kf\":-1.31},\"weather\":[{\"id\":803,\"main\":\"Clouds\",\"description\":\"broken clouds\",\"icon\":\"04d\"}],\"clouds\":{\"all\":68},\"wind\":{\"speed\":2.71,\"deg\":337.008},\"sys\":{\"pod\":\"d\"},\"dt_txt\":\"2018-08-18 06:00:00\"},{\"dt\":1534582800,\"main\":{\"temp\":22.64,\"temp_min\":22.64,\"temp_max\":23.51,\"pressure\":1022.21,\"sea_level\":1032.39,\"grnd_level\":1022.21,\"humidity\":74,\"temp_kf\":-0.87},\"weather\":[{\"id\":801,\"main\":\"Clouds\",\"description\":\"few clouds\",\"icon\":\"02d\"}],\"clouds\":{\"all\":24},\"wind\":{\"speed\":3.02,\"deg\":354.507},\"sys\":{\"pod\":\"d\"},\"dt_txt\":\"2018-08-18 09:00:00\"},{\"dt\":1534593600,\"main\":{\"temp\":24.32,\"temp_min\":24.32,\"temp_max\":24.76,\"pressure\":1022.01,\"sea_level\":1032.15,\"grnd_level\":1022.01,\"humidity\":74,\"temp_kf\":-0.44},\"weather\":[{\"id\":500,\"main\":\"Rain\",\"description\":\"light rain\",\"icon\":\"10d\"}],\"clouds\":{\"all\":20},\"wind\":{\"speed\":2.51,\"deg\":350.5},\"rain\":{\"3h\":0.495},\"sys\":{\"pod\":\"d\"},\"dt_txt\":\"2018-08-18 12:00:00\"},{\"dt\":1534604400,\"main\":{\"temp\":24.38,\"temp_min\":24.38,\"temp_max\":24.38,\"pressure\":1021.82,\"sea_level\":1032.09,\"grnd_level\":1021.82,\"humidity\":66,\"temp_kf\":0},\"weather\":[{\"id\":500,\"main\":\"Rain\",\"description\":\"light rain\",\"icon\":\"10d\"}],\"clouds\":{\"all\":0},\"wind\":{\"speed\":3.06,\"deg\":348.503},\"rain\":{\"3h\":2.1},\"sys\":{\"pod\":\"d\"},\"dt_txt\":\"2018-08-18 15:00:00\"},{\"dt\":1534615200,\"main\":{\"temp\":21.07,\"temp_min\":21.07,\"temp_max\":21.07,\"pressure\":1021.97,\"sea_level\":1032.35,\"grnd_level\":1021.97,\"humidity\":56,\"temp_kf\":0},\"weather\":[{\"id\":800,\"main\":\"Clear\",\"description\":\"clear sky\",\"icon\":\"01d\"}],\"clouds\":{\"all\":0},\"wind\":{\"speed\":2.81,\"deg\":325.002},\"rain\":{},\"sys\":{\"pod\":\"d\"},\"dt_txt\":\"2018-08-18 18:00:00\"},{\"dt\":1534626000,\"main\":{\"temp\":15.67,\"temp_min\":15.67,\"temp_max\":15.67,\"pressure\":1023.38,\"sea_level\":1033.67,\"grnd_level\":1023.38,\"humidity\":68,\"temp_kf\":0},\"weather\":[{\"id\":800,\"main\":\"Clear\",\"description\":\"clear sky\",\"icon\":\"01n\"}],\"clouds\":{\"all\":0},\"wind\":{\"speed\":2.56,\"deg\":333.501},\"rain\":{},\"sys\":{\"pod\":\"n\"},\"dt_txt\":\"2018-08-18 21:00:00\"},{\"dt\":1534636800,\"main\":{\"temp\":12.21,\"temp_min\":12.21,\"temp_max\":12.21,\"pressure\":1023.52,\"sea_level\":1033.85,\"grnd_level\":1023.52,\"humidity\":89,\"temp_kf\":0},\"weather\":[{\"id\":800,\"main\":\"Clear\",\"description\":\"clear sky\",\"icon\":\"01n\"}],\"clouds\":{\"all\":0},\"wind\":{\"speed\":1.28,\"deg\":157.002},\"rain\":{},\"sys\":{\"pod\":\"n\"},\"dt_txt\":\"2018-08-19 00:00:00\"},{\"dt\":1534647600,\"main\":{\"temp\":11.15,\"temp_min\":11.15,\"temp_max\":11.15,\"pressure\":1023,\"sea_level\":1033.33,\"grnd_level\":1023,\"humidity\":87,\"temp_kf\":0},\"weather\":[{\"id\":800,\"main\":\"Clear\",\"description\":\"clear sky\",\"icon\":\"01n\"}],\"clouds\":{\"all\":0},\"wind\":{\"speed\":1.72,\"deg\":177.001},\"rain\":{},\"sys\":{\"pod\":\"n\"},\"dt_txt\":\"2018-08-19 03:00:00\"}],\"city\":{\"id\":3092909,\"name\":\"Lublewo Gdanskie\",\"coord\":{\"lat\":54.2846,\"lon\":18.5039},\"country\":\"PL\"}}".replace("\"","\\\"")
val List<String> rainValues = executeCommandLine("/bin/sh@@-c@@/usr/bin/echo \"" + forecastJson + "\" | /usr/bin/jq '.list[].rain.\"3h\" | numbers'",1000).split("\n")
logDebug("Rules","Test: rainValues=[{}]",rainValues.toString)

This logs…

Test: rainValues=[[0.495, 2.1]]

[Michal_Szymanski]

@vzorglub

I got it the wrong way around:

Ok it works

			var String[] rainValues  = transform("JS","rainvalues.js",forecastJson).replace("[", "").replace("]", "").split(",") 

  			rainfallMm = 0

			if(rainValues.get(0)!="NULL")		
				for (var i = 0; i < rainValues.length; i++) {						
					rainfallMm = rainfallMm  + (Double::parseDouble(rainValues.get(i)))
				}

[vzorglub (Vincent Regaud)]

Yeahhhh!!!