Creating a new JSON by extracting a specific branch or node from an existing JSON data

Question

Creating a new JSON by extracting a specific branch or node from an existing JSON data

I have a Nuki Smartlock and when I make two API calls to the Nuki Bridge, I receive JSON responses. I want to apply the same logic to both responses:

When requesting for current states, the JSON looks like this:

[{
  "deviceType": 0,
  "nukiId": 1234,
  "name": "NukiDoor",
  "firmwareVersion": "2.9.10",
  "lastKnownState": {
    "mode": 2,
    "state": 3,
    "stateName": "unlocked",
    "batteryCritical": false,
    "batteryCharging": false,
    "batteryChargeState": 72,
    "doorsensorState": 2,
    "doorsensorStateName": "door closed",
    "timestamp": "2021-01-04T13:02:52+00:00"
  }
}]

And if I perform an Action (like opening the door), I get this additional JSON data:

{
  "deviceType": 0,
  "nukiId": 1234,
  "mode": 2,
  "state": 3,
  "stateName": "unlocked",
  "batteryCritical": "OFF",
  "batteryCharging": "OFF",
  "batteryChargeState": 72,
  "doorsensorState": 2,
  "doorsensorStateName": "door closed"
}

Therefore, the .lastKnowState node from the Status-Request matches the pure JSON structure of the Action-JSON.

To achieve this consistency in JavaScript, we need to "extract" the lastKnownState node from the first JSON response. How can this be done effectively?

javascript json

Answer 1

Answer №1

In the data you are receiving, there is a JSON array containing one object which includes another nested JSON object called lastKnownState. To access the information within this nested object, you first need to extract the object at index 0 of the array. This will give you the outer JSON object that contains your desired lastKnownState. Then, you can use dot notation to specifically extract the details from the lastKnownState JSON.

For a more in-depth understanding of how to work with JSON objects and arrays, I recommend checking out the following resources: https://developer.mozilla.org/en-US/docs/Learn/JavaScript/Objects/Basics

You might also find this guide helpful: https://developer.mozilla.org/en-US/docs/Learn/JavaScript/Objects/JSON

const data = [{
  "deviceType": 0,
  "nukiId": 1234,
  "name": "NukiDoor",
  "firmwareVersion": "2.9.10",
  "lastKnownState": {
    "mode": 2,
    "state": 3,
    "stateName": "unlocked",
    "batteryCritical": false,
    "batteryCharging": false,
    "batteryChargeState": 72,
    "doorsensorState": 2,
    "doorsensorStateName": "door closed",
    "timestamp": "2021-01-04T13:02:52+00:00"
  }
}];

const lastKnownState = data[0].lastKnownState;

console.log(lastKnownState, null, 2)

Answer 2

In the data you are receiving, there is a JSON array containing one object which includes another nested JSON object called lastKnownState. To access the information within this nested object, you first need to extract the object at index 0 of the array. This will give you the outer JSON object that contains your desired lastKnownState. Then, you can use dot notation to specifically extract the details from the lastKnownState JSON.

For a more in-depth understanding of how to work with JSON objects and arrays, I recommend checking out the following resources: https://developer.mozilla.org/en-US/docs/Learn/JavaScript/Objects/Basics

You might also find this guide helpful: https://developer.mozilla.org/en-US/docs/Learn/JavaScript/Objects/JSON

const data = [{
  "deviceType": 0,
  "nukiId": 1234,
  "name": "NukiDoor",
  "firmwareVersion": "2.9.10",
  "lastKnownState": {
    "mode": 2,
    "state": 3,
    "stateName": "unlocked",
    "batteryCritical": false,
    "batteryCharging": false,
    "batteryChargeState": 72,
    "doorsensorState": 2,
    "doorsensorStateName": "door closed",
    "timestamp": "2021-01-04T13:02:52+00:00"
  }
}];

const lastKnownState = data[0].lastKnownState;

console.log(lastKnownState, null, 2)

Creating a new JSON by extracting a specific branch or node from an existing JSON data

Answer №1

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