JS: array of objects into object with nesting

Question

I need to convert this kind of array:

const obj = [{
    name: 'firstLink',
    type: 'topic',
    id: 'ab75ca14-dc7c-4c3f-9115-7b1b94f88ff6',
    spacing: 1, // root
}, {
    name: 'secondLink',
    type: 'source',
    id: 'd93f154c-fb1f-4967-a70d-7d120cacfb05',
    spacing: 2, // child of previous object
}, {
    name: 'thirdLink',
    type: 'topic',
    id: '31b85921-c4af-48e5-81ae-7ce45f55df81',
    spacing: 1, // root
}]

Into this object:

const map = {
    'ab75ca14-dc7c-4c3f-9115-7b1b94f88ff6': {
        name: 'firstLink',
        type: 'topic',
        children: {
            'd93f154c-fb1f-4967-a70d-7d120cacfb05': {
                name: 'secondLink',
                type: 'source',
            }
        },
    },
    '31b85921-c4af-48e5-81ae-7ce45f55df81': {
        name: 'thirdLink',
        type: 'topic',
    }
}

There might be up to 10 nestings, may be more (defined as spacing in the array). How can i do that? I can use only pure js and lodash library.

then it should become a child of the last object with spacing: 2 — stkvtflw
– stkvtflw, Commented Jun 6, 2016 at 11:55
How do you know which child belongs to which parent? Is it guaranteed to be the previous array element? — Patrick Evans
– Patrick Evans, Commented Jun 6, 2016 at 12:02
I would advise you to refactor this using links like paranedId. Sou you don't need to order your array properly.. Just point parentid: 'ab75ca14-dc7c-4c3f-9115-7b1b94f88ff6' instead of spacing: 2 — Max
– Max, Commented Jun 6, 2016 at 12:36
@Max, it's impossible, because the array is actually interpreted lines of text. — stkvtflw
– stkvtflw, Commented Jun 6, 2016 at 13:47

Nina Scholz · Accepted Answer · 2016-06-06 14:32:19Z

You could use an array as reference to the inserted nested object.

var obj = [{ name: 'firstLink', type: 'topic', id: 'ab75ca14-dc7c-4c3f-9115-7b1b94f88ff6', spacing: 1, }, { name: 'secondLink', type: 'source', id: 'd93f154c-fb1f-4967-a70d-7d120cacfb05', spacing: 2, }, { name: 'thirdLink', type: 'topic', id: '31b85921-c4af-48e5-81ae-7ce45f55df81', spacing: 1, }],
    map = {};

obj.forEach(function (a) {
    this[a.spacing - 1][a.id] = { name: a.name, type: a.type, children: {}};
    this[a.spacing] = this[a.spacing - 1][a.id].children;
}, [map]);

console.log(map);

If you do not like empty children objects, you could use this proposal. It creates children properties only if necessary.

var obj = [{ name: 'firstLink', type: 'topic', id: 'ab75ca14-dc7c-4c3f-9115-7b1b94f88ff6', spacing: 1, }, { name: 'secondLink', type: 'source', id: 'd93f154c-fb1f-4967-a70d-7d120cacfb05', spacing: 2, }, { name: 'thirdLink', type: 'topic', id: '31b85921-c4af-48e5-81ae-7ce45f55df81', spacing: 1, }],
    map = {};

obj.forEach(function (a) {
    this[a.spacing - 1].children = this[a.spacing - 1].children || {};
    this[a.spacing - 1].children[a.id] = { name: a.name, type: a.type};
    this[a.spacing] = this[a.spacing - 1].children[a.id];
}, [map]);

map = map.children;
console.log(map);

Collectives™ on Stack Overflow

JS: array of objects into object with nesting

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related