How to properly un-nest and flatten an array of javascript objects with an array inside them (X-amount of times)

Question

I'm currently working with an array of javascript objects with X-amount of array's with the same type of object inside it, in a specific property (in this case, 'modelChildren')

I would like to flatten this into just one array of objects, and return the level at which it was found. The solution does not have to be plain javascript, as I use lodash for many situations. Ideally I would also like to remove the 'modelChildren' field once finished.

Any help would be appreciated. Thanks!

input:

[{
  id: 1,
  name: foo
  modelChildren: [
   {
    id: 2,
    name: bar,
    modelChildren: [
      {
      id: 3,
      name: foobar
      },
      {
      id: 4,
      name: foobarfoo
      }
    ] 
   }
  ] 
}]

expected result:

[{
   id: 1,
   name: foo,
   level: 1
 {
   id: 2,
   name: bar,
   level: 2
 },
 {
   id: 3,
   name: foobar,
   level: 3
 },
 {
   id: 4,
   name: foobarfoo
   level: 3
 }]

libik · Accepted Answer · 2017-01-04 16:05:52Z

This can be quite easy, it is just Tree Traversal

So you just need to traverse it and remember the level, while storing "nodes" when you are in them.

For example this code

const source = [{
    id: 1,
    name: 'foo',
    modelChildren: [
        {
            id: 2,
            name: 'bar',
            modelChildren: [
                {
                    id: 3,
                    name: 'foobar'
                },
                {
                    id: 4,
                    name: 'foobarfoo'
                }
            ]
        }
    ],
}, {
    id: 5,
    name: 'foo',
    modelChildren: [
        {
            id: 6,
            name: 'bar',
            modelChildren: [
                {
                    id: 7,
                    name: 'foobar'
                },
                {
                    id: 8,
                    name: 'foobarfoo'
                }
            ]
        },
        {
            id: 9,
            name: 'bar',
            modelChildren: [
                {
                    id: 10,
                    name: 'foobar'
                },
                {
                    id: 11,
                    name: 'foobarfoo'
                }
            ]
        }
    ],
}
];
const newSource = [];
const _ = require('lodash');

function doIt(items, level) {
    if (!items) {
        return;
    }

    items.forEach(item => {
        newSource.push(_.merge({level}, _.pick(item, ['id', 'name'])));
        doIt(item.modelChildren, level + 1);
    })
}

doIt(source, 1);
console.log(newSource);

Having this output

[ { level: 1, id: 1, name: 'foo' },
  { level: 2, id: 2, name: 'bar' },
  { level: 3, id: 3, name: 'foobar' },
  { level: 3, id: 4, name: 'foobarfoo' },
  { level: 1, id: 5, name: 'foo' },
  { level: 2, id: 6, name: 'bar' },
  { level: 3, id: 7, name: 'foobar' },
  { level: 3, id: 8, name: 'foobarfoo' },
  { level: 2, id: 9, name: 'bar' },
  { level: 3, id: 10, name: 'foobar' },
  { level: 3, id: 11, name: 'foobarfoo' } ]

Collectives™ on Stack Overflow

How to properly un-nest and flatten an array of javascript objects with an array inside them (X-amount of times)

1 Answer 1

Comments

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Related