How to configure value_template to extract data from JSON array without name

Configuration
1

Hi,
I would appreciate help with configuring a REST full sensor to extract multiple sensors from one REST call using templates.
I can extract any value, e.g. temperatur from the first element of the array with below configuration.

However struggle to figure out how I can access any attribute of the second element of the array.
For example the value for JSON Path $.[?(@.etagenname=="OG")].raeume[?(@.name=="Bad")].temperatur

Here is my configuration

sensor:
  - platform: rest
    resource: http://192.168.2.3/get/json/v1/1/temps
    scan_interval: 60
    name: temperatur_sensor
    value_template: 'OK'
    json_attributes:
      - temperature
      - raeume
  - platform: template
    sensors:
      wohnzimmer_ist_temperatur_neu:
        device_class: temperature
        unit_of_measurement: "Ā°C"
        value_template: "{{ states.sensor.temperatur_sensor.attributes.raeume[0].temperatur|round(2) }}"

which returns 17.73 as desired.

My JSON looks like below:

[
    {
        "etagenname": "DG",
        "id": 1,
        "raeume": [
            {
                "total_offset": 0.2,
                "solltemperatur": 12,
                "temperatur": 17.725490196078432,
                "name": "Bad"
            },
            {
                "total_offset": 0.2,
                "solltemperatur": 18,
                "temperatur": 19.137254901960784,
                "name": "Lena"
            }
        ]
    },
    {
        "etagenname": "OG",
        "id": 2,
        "raeume": [
            {
                "total_offset": -0.11529411764705755,
                "solltemperatur": 19.9,
                "temperatur": 16.764705882352942,
                "name": "Bad"
            },
            {
                "total_offset": 0.08,
                "solltemperatur": 16,
                "temperatur": 18.352941176470587,
                "name": "Schlafzimmer"
            }
        ]
    }
]
1 Like
2

Hmm. I would jump on Discord and ask the devs if the RESTfull sensor supports a JSON array at the top level. Possibly it only grabs the first element.

If not the only suggestion I would have is to retrieve the raw data and load the array into an object then process that, or maybe do it with Node Red.

3

You can use top level arrays.

Use this tool to get the path to the data you want. Just replace x with value_json

https://jsonpathfinder.com/

You can get all the temperature sensors with the one rest call using the new rest integration rather than the rest sensor platform. No template sensors required:

rest:
  - resource: http://192.168.2.3/get/json/v1/1/temps
    scan_interval: 60
    sensor:
      - name: "DG Bad" #change this to what you want
        value_template: "{{ value_json[0].raeume[0].temperatur }}"
        device_class: temperature
        unit_of_measurement: "Ā°C"
      - name: "DG Lena" #change this to what you want
        value_template: "{{ value_json[0].raeume[1].temperatur }}"
        device_class: temperature
        unit_of_measurement: "Ā°C"
      - name: "OG Bad" #change this to what you want
        value_template: "{{ value_json[1].raeume[0].temperatur }}"
        device_class: temperature
        unit_of_measurement: "Ā°C"
      - name: "OG Schlafzimmer" #change this to what you want
        value_template: "{{ value_json[1].raeume[1].temperatur }}"
        device_class: temperature
        unit_of_measurement: "Ā°C"
2 Likes
4

Ah - makes sense when you see it done that way.

5

Thanks for the tip.

This is working, reading the documentation and posts here in the community I however got the impression that using the template sensor is the way how extracting multiple sensors from one REST call should be done.
Could you share a bit of light for a HA green-horn on the difference between the two approaches?
Will your sample extract the sensor values from a single rest call or will a rest call per sensor be initiated?

6

Thatā€™s the way it was done until the rest integration was introduced. You can still do it that way but itā€™s more work and less efficient.

7

Thanks for the clarification, sounds great!

9

is there a way to use a filter to find the index. like raeme[?ā€˜nameā€™=ā€˜Badā€™] instead of raeume[1] or raeume[2]

sincearly
Fredrik

10

Apologies for the hijack but this looks like the same issue that I am trying to solve though I cant seem to get it working using the solution from Post #3.

I too have an unlabelled JSON top level that looks like this;

[
	{
		"releaseDate": "2023-03-05",
		"mediaItem": {
			"id": 11,
			"title": "The Last of Us",
			"releaseDate": "2023-01-15",
			"slug": "the-last-of-us-2023",
			"mediaType": "tv",
			"seen": true
		},
		"episode": {
			"id": 240,
			"title": "When We Are in Need",
			"episodeNumber": 8,
			"seasonNumber": 1,
			"releaseDate": "2023-03-05",
			"seen": true,
			"isSpecialEpisode": false
		}
	},
	{
		"releaseDate": "2023-03-08",
		"mediaItem": {
			"id": 33,
			"title": "The Mandalorian",
			"releaseDate": "2019-11-12",
			"slug": "the-mandalorian-2019",
			"mediaType": "tv",
			"seen": true
		},
		"episode": {
			"id": 267,
			"title": "Chapter 18",
			"episodeNumber": 2,
			"seasonNumber": 3,
			"releaseDate": "2023-03-08",
			"seen": false,
			"isSpecialEpisode": false
		}
	}
]

and my config looks like thisā€¦

rest:
  - resource: http://resource url (Produced the above JSON)
    scan_interval: 60
    sensor:
      - name: "upcoming_ep1"
        value_template: "{{ value_json[0].releaseDate }}"
      - name: "upcoming_ep2"
        value_template: "{{ value_json[1].releaseDate }}"

I am only trying to fetch the release date currently as that seemed a simple place to start as itā€™s a basic entry rather than being a further nested entry but even that is not working. In the Developer > Sates tab, I canā€™t even find the ā€œupcoming_ep1ā€ or ā€œep2ā€ entities. Iā€™ve checked configuration and restarted HA and still nothing.

Any ideas what Iā€™ve missed? sure its something simple.

11

Hi,
if you want to get the release date for the episode, you would need to modify your value_template like below:

rest:
  - resource: http://resource url (Produced the above JSON)
    scan_interval: 60
    sensor:
      - name: "upcoming_ep1"
        value_template: "{{ value_json[0].episode.releaseDate }}"
      - name: "upcoming_ep2"
        value_template: "{{ value_json[1].episode.releaseDate }}"
12

Must be something in the logs. Your sensor configuration looks good and the template is correct (@urmel ā€” there is a releaseDate as well as an episode.releaseDate). Make sure you only have one top-level rest: declaration.