Javascript update values in nested object by array path

Question

Given the nested object:

{
    name: 'UK',
    toggled: false,
    active: false,
    children: [{
            name: 'Region 1',
            active: false,
            toggled: false,
            children: [{
                    name: 'Heathrow T1',
                    toggled: false,
                    active: false,
                    children: []
                },
                {
                    name: 'HTT',
                    toggled: false,
                    active: false,
                    children: []
                },
            ]
        },
        {
            name: 'Region 2',
            active: false,
            toggled: false,
            children: [{
                name: Gatwick North,
                active: false,
                toggled: false,
                children: []
            }]
        }
    ]
}

and the given path

['UK', 'Region 2', 'Gatwick North']

how can I manage to add active/toggled properties to true for the path in the nested object matching the above array.

The output should be the following:

{
    name: 'UK',
    toggled: true,
    active: true,
    children: [{
            name: 'Region 1',
            active: false,
            toggled: false,
            children: [{
                    name: 'Heathrow T1',
                    toggled: false,
                    active: false,
                    children: []
                },
                {
                    name: 'HTT',
                    toggled: false,
                    active: false,
                    children: []
                },
            ]
        },
        {
            name: 'Region 2',
            active: true,
            toggled: true,
            children: [{
                name: 'Gatwick North',
                active: true,
                toggled: true,
                children: []
            }]
        }
    ]
}

I was trying to implement this with recursion with no success so far. I was searching through questions and none of them matched my current situation.

Please show what you tried rather than merely writing that you did. — Dexygen, Nov 27 '18 at 10:45

score 3 · Accepted Answer · answered Nov 27 '18 at 11:15

simple example of using recursion, explanations are in code as comments

const obj = {name: 'UK',toggled: false,active: false,children: [{name: 'Region 1',active: false,toggled: false,children: [{name: 'Heathrow T1',toggled: false,active: false,children: []},{name: 'HTT',toggled: false,active: false,children: []},]},{name: 'Region 2',active: false,toggled: false,children: [{name: 'Gatwick North',active: false,toggled: false,children: []}]}]};

const checkAndChange = (obj) => { // function that will check if name exists in array and change toggle and active properties
  const arr = ['UK', 'Region 2', 'Gatwick North'];
  if (arr.includes(obj.name)) {
    obj.toggled = true;
    obj.active = true;
  }
}

const recursion = (obj) => {
   const o = obj;
   checkAndChange(o); // check if name exists in array and change toggle and active properties
   if (o.children.length > 0) { // check if has children
     o.children.forEach(v => { // if has children do the same recursion for every children
       recursion(v);
      });
   }
   return o; // return final new object
}

console.log(recursion(obj));

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Dilip Belgumpi · Answer 2 · 2018-11-27T11:26:56.237

0

Use recursive method to find the path and update the value.

var obj = [{name: 'UK',toggled: false,active: false,children: [{name: 'Region 1',active: false,toggled: false,children: [{name: 'Heathrow T1',toggled: false,active: false,children: []},{name: 'HTT',toggled: false,active: false,children: []},]},{name: 'Region 2',active: false,toggled: false,children: [{name: 'Gatwick North',active: false,toggled: false,children: []}]}]}];

function FilterArray(temp2,i){
 temp2.filter(function(el){
      if(el['name']==path[i]){
         el['toggled']=true;
          el['active']=true;
        if(i!=path.length-1){
          FilterArray(el['children'],++i);
        }
      }
  });
}

console.log("Before");
console.log(obj);
var path=['UK', 'Region 2', 'Gatwick North'];
FilterArray(obj,0);

console.log("After");
console.log(obj);

edited Nov 27 '18 at 11:26

answered Nov 27 '18 at 11:13

Dilip Belgumpi

658
4
13

your example isn't working, properties are still false – Artyom Amiryan Nov 27 '18 at 11:16
@ArtyomAmiryan I thought only last children toggle should be true. Now edited the code, please check – Dilip Belgumpi Nov 27 '18 at 11:19
The dataset it was supposed to be an object, not an array – Gusti Nov 28 '18 at 08:20

score 0 · Answer 3 · answered Nov 13 '19 at 20:18

Based on this answer on a very similar question:

function deep_value(obj, path){
    for (var i=0; i<path.length; i++){
        obj = obj[path[i]];
    };
    return obj;
};

Use it like this:

var obj = {
  foo: { bar: 'baz' }
};

alert(deep_value(obj, ['foo','bar'])); // alerts "baz"

Extra: the same function can also be used for arrays

var arr = [
  ['item 0.0', 'item 0.1'],
  ['item 1.0', 'item 1.1'],
  ['item 2.0', 'item 2.1'],
]
console.log(deep_value(arr, [2,1])); // logs "item 2.1"

Codepen

score 0 · Answer 4 · edited Dec 06 '19 at 21:12

This will work for nested arrays.

parameters:
- array: array to update
- path: what to update ([0] - array[0], [2,1] - array[2][1], etc.)
- data: data to assign

    function updateArray(array, path, data) {
        const index = path.shift();
        if (path.length) {
            if (!Array.isArray(array[index])) {
                array[index] = [];
            }
            updateArray(array[index], path, data);
        } else {
            array[index] = data;
        }
    }

Javascript update values in nested object by array path

4 Answers4

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