row-to-tree

Converts an array of objects into a tree structure, backend or frontend, with an optimal linear complexity O(n), taking into account various useful options to manage your data. If you want to test it, go to the demo!

There is no dependency in this ultralight library, all the code is here!

Why?

When you make a SQL request, you often get an array of rows, each of them being linked to another one in a parent/child relation. And you may want to use this array to display a tree, for example in a Vuetify component.

This module helps you convert the original array into an array of parents and child, building the expected tree:

Example

The test file provides an example of what could be done. Suppose you have the following table:

id	id_parent	name
1	null	ROOT
2	1	NODE
4	1	LEAF SISTER
6	2	OTHER LEAF
5	null	NEW ROOT

You will end up with an array of objects,

How?

Installation

npm install --save row-to-tree

Usage

const { rowToTree } = require("row-to-tree");

const data = [
  { id: 1, id_parent: null, name: "ROOT" },
  { id: 2, id_parent: 1, name: "NODE" },
  { id: 4, id_parent: 1, name: "LEAF SISTER" },
  { id: 6, id_parent: 2, name: "OTHER LEAF" },
  { id: 5, id_parent: null, name: "NEW ROOT" },
];

console.log(rowToTree(data));

You will get this nested array:

[
  {
    id: 1,
    id_parent: null,
    name: "ROOT",
    children: [
      {
        id: 2,
        id_parent: 1,
        name: "NODE",
        children: [
          {
            id: 6,
            id_parent: 2,
            name: "OTHER LEAF",
            children: [],
          },
        ],
      },
      {
        id: 4,
        id_parent: 1,
        name: "LEAF SISTER",
        children: [],
      },
    ],
  },
  {
    id: 5,
    id_parent: null,
    name: "NEW ROOT",
    children: [],
  },
];

API

rowToTree(data, options)

Convert an array of objects into a tree structure: returns an array of root objects.

Key		Type	Optional	Description	Default
data		Array	❌	the array of objects to convert
options		JSON	✅	the JSON of customized paramaters	{}
├──	idKey	String	✅	the name of the key that identifies an object	"id"
├──	parentKey	String	✅	the name of the key that identifies the parent of an object	"id_parent"
├──	childrenKey	String	✅	the name of the key that will contain the children of an object	"children"
└──	cleanEmptyChildren	Boolean	✅	delete the `childrenKey` if the node has no child, i.e. a leaf.	false

Licence

MIT