What is the JavaScript library or module that can update json based on jsonpath?

Question

I've used some Java library to achieve this before. I thought since json is more intrinsic to JavaScript to Java, it should be quite easy to find a library that does that. But surprisingly no.

An example of what I look for is: given a Json object:

 {
  "store": {
    "book": [
      {
        "category": "reference",
        "author": "Nigel Rees",
        "title": "Sayings of the Century",
        "price": 8.95
      },
      {
        "category": "fiction",
        "author": "Evelyn Waugh",
        "title": "Sword of Honour",
        "price": 12.99
      },
      {
        "category": "fiction",
        "author": "Herman Melville",
        "title": "Moby Dick",
        "isbn": "0-553-21311-3",
        "price": 8.99
      },
      {
        "category": "fiction",
        "author": "J. R. R. Tolkien",
        "title": "The Lord of the Rings",
        "isbn": "0-395-19395-8",
        "price": 22.99
      }
    ],
    "bicycle": {
      "color": "red",
      "price": 19.95
    }
  }
}

and a Jsonpath like:

 '$..author'

I can call a JavaScript function that takes JsonObject, JsonPath and newValue (Shakespeare) as the input parameters, and change the value of all occurrences of the JSONPATH to a new value, e.g. to

 {
  "store": {
    "book": [
      {
        "category": "reference",
        "author": "Shakespeare",
        "title": "Sayings of the Century",
        "price": 8.95
      },
      {
        "category": "fiction",
        "author": "Shakespeare",
        "title": "Sword of Honour",
        "price": 12.99
      },
      {
        "category": "fiction",
        "author": "Shakespeare",
        "title": "Moby Dick",
        "isbn": "0-553-21311-3",
        "price": 8.99
      },
      {
        "category": "fiction",
        "author": "Shakespeare",
        "title": "The Lord of the Rings",
        "isbn": "0-395-19395-8",
        "price": 22.99
      }
    ],
    "bicycle": {
      "color": "red",
      "price": 19.95
    }
  }
}

Any suggestions?

Answer 1

Try to use jsonpath npm package.

use apply method to change values of a JSON object and returns nodes. You'll need to add some method that will change the value according to the path from each node.

const _ = require('lodash');
var jp = require('jsonpath');
const data = {
"store": {
  "book": [ 
    {
      "category": "reference",
      "author": "Nigel Rees",
      "title": "Sayings of the Century",
      "price": 8.95
    }, {
      "category": "fiction",
      "author": "Evelyn Waugh",
      "title": "Sword of Honour",
      "price": 12.99
    }, {
      "category": "fiction",
      "author": "Herman Melville",
      "title": "Moby Dick",
      "isbn": "0-553-21311-3",
      "price": 8.99
    }, {
       "category": "fiction",
      "author": "J. R. R. Tolkien",
      "title": "The Lord of the Rings",
      "isbn": "0-395-19395-8",
      "price": 22.99
    }
  ],
  "bicycle": {
    "color": "red",
    "price": 19.95
  }
}
  }
    var nodes = jp.apply(data, '$..author', function(value) { return value.toUpperCase() });
    // [
    //   { path: ['$', 'store', 'book', 0], value: 'NIGEL REES' },
    //   { path: ['$', 'store', 'book', 1], value: 'EVELYN WAUGH' },
    //   { path: ['$', 'store', 'book', 2], value: 'HERMAN MELVILLE' },
    //   { path: ['$', 'store', 'book', 3], value: 'J. R. R. TOLKIEN' }
    // ]

    function chnageValueByPath(object, path, value) {
       if(Array.isArray(path) && path[0] === '$') {
            const pathWithoutFirstElement = path.slice(1);
            _.set(object, pathWithoutFirstElement, value);
       }
    }

    function changeValuesByPath(object, nodes, lastPropertyName) {
        nodes.forEach((node)=> {
            chnageValueByPath(object, node.path.concat(lastPropertyName), node.value);
        })

        return object;
    }

    const result = changeValuesByPath(data, nodes, 'author');
    console.log(result);