We Keep Coding

Form a nested tree from an array of objects in javascript

So there is array of objects of below format
let inputs = [
{
"id": "614344d9d9c21c0001e6af2e",
"groupName": "Unassigned",
"parentGroup": "null"
},
{
"id": "614447da152f69c3c1d52f2e",
"groupName": "P1",
"parentGroup": "null"
},
{
"id": "614447da152f69c3c1d52f38",
"groupName": "K1",
"parentGroup": "C1"
},
{
"id": "614447da152f69c3c1d52f3e",
"groupName": "A2",
"parentGroup": "C2"
},
{
"id": "614447da152f69c3c1d52f40",
"groupName": "G1",
"parentGroup": "P2"
},
{
"id": "614447da152f69c3c1d52f46",
"groupName": "F1",
"parentGroup": "null"
},
{
"id": "614447da152f69c3c1d52f30",
"groupName": "P2",
"parentGroup": "null"
},
{
"id": "614447da152f69c3c1d52f36",
"groupName": "C2",
"parentGroup": "P1"
},
{
"id": "614447da152f69c3c1d52f3c",
"groupName": "A1",
"parentGroup": "C2"
},
{
"id": "614447da152f69c3c1d52f34",
"groupName": "C1",
"parentGroup": "P1"
},
{
"id": "614447da152f69c3c1d52f32",
"groupName": "P3",
"parentGroup": "null"
},
{
"id": "614447da152f69c3c1d52f3a",
"groupName": "K2",
"parentGroup": "C1"
},
{
"id": "614447da152f69c3c1d52f42",
"groupName": "GG1",
"parentGroup": "G1"
},
{
"id": "614447da152f69c3c1d52f44",
"groupName": "GGG1",
"parentGroup": "GG1"
}
]
i am trying to create a tree structure of format
{name:'p1',children:[{name:'c1':children:[]}]}
so i sorted all the elements of given array considering element with parentGroup as "null" to be at the top of the array.
let finalArr = [];
inputs.sort((a,b)=> (a.parentGroup === "null") ? -1 : 1);
And for each element of the inputs array, i was iterating below logic
inputs.forEach(ele => {
if(ele.parentGroup === "null"){
let child= {name:ele.groupName,children:[]};
finalArr.push(child);
}else{
finalArr.forEach(item => {
this.findNode(item,ele);
})
}
});
If the 'parentGroup' of element is "null", then create a leaf kind of obj and push the element to 'finalArr' array
Else, then iterate across all the elements of 'finalArr' over a recursion function
public findNode(ele, obj){
if(ele.children.length === 0){
if(ele.name === obj.parentGroup){
let child = {name:obj.groupName, children:[]};
ele.children.push(child);
}
}else{
let j = ele.children.length-1;
this.findNode(ele.children[j--],obj);
}
}
This recursion function will check the element has children or not, if no children, then compare the parentGroup of given obj, with name of element from 'FinalArr'.
if so ,push the current obj to the children of the element of finalArr.
else, that is, when children has more elements, the same recursion will be triggered until depth of the element is reached.
With this i tought i would make a tree structure with given inputs array, but when a parent has more children, of same level, this logic fails,
so the inputs array has 'c1' which is a child of 'p1', but nly the child 'c2' resides, not sure the what is that i missed.

You could take a standard algorithm for getting a tree with given data
const
getTree = (data, id, parent, root, fn = o => o) => {
var t = {};
data.forEach(o => ((t[o[parent]] ??= {}).children ??= []).push(Object.assign(t[o[id]] = t[o[id]] || {}, fn(o))));
return t[root].children;
},
data = [{ id: "614344d9d9c21c0001e6af2e", groupName: "Unassigned", parentGroup: "null" }, { id: "614447da152f69c3c1d52f2e", groupName: "P1", parentGroup: "null" }, { id: "614447da152f69c3c1d52f38", groupName: "K1", parentGroup: "C1" }, { id: "614447da152f69c3c1d52f3e", groupName: "A2", parentGroup: "C2" }, { id: "614447da152f69c3c1d52f40", groupName: "G1", parentGroup: "P2" }, { id: "614447da152f69c3c1d52f46", groupName: "F1", parentGroup: "null" }, { id: "614447da152f69c3c1d52f30", groupName: "P2", parentGroup: "null" }, { id: "614447da152f69c3c1d52f36", groupName: "C2", parentGroup: "P1" }, { id: "614447da152f69c3c1d52f3c", groupName: "A1", parentGroup: "C2" }, { id: "614447da152f69c3c1d52f34", groupName: "C1", parentGroup: "P1" }, { id: "614447da152f69c3c1d52f32", groupName: "P3", parentGroup: "null" }, { id: "614447da152f69c3c1d52f3a", groupName: "K2", parentGroup: "C1" }, { id: "614447da152f69c3c1d52f42", groupName: "GG1", parentGroup: "G1" }, { id: "614447da152f69c3c1d52f44", groupName: "GGG1", parentGroup: "GG1" }],
tree = getTree(data, 'groupName', 'parentGroup', null, ({ groupName: name }) => ({ name }));
console.log(tree);
.as-console-wrapper { max-height: 100% !important; top: 0; }

I think the issue is how finalArr is used to generate the html elements.
When doing console.log(finalArr) it looks like the code block below. So it seems to me like the code you have to build the structure of finalArr is working fine.
// console.log(finalArr)
[
{ "name": "P3", "children": [] },
{
"name": "P2",
"children": [
{
"name": "G1",
"children": [
{ "name": "GG1", "children": [
{ "name": "GGG1", "children": [] }
]
}
]
}
]
},
{ "name": "F1", "children": [] },
{
"name": "P1",
"children": [
{ "name": "C2", "children": [
{ "name": "A1", "children": [] }
]
}
]
},
{ "name": "Unassigned", "children": [] }
]
EDIT
As OP mentioned in the comment C1 was missing. I've introduced a root element that will have the finalArr as its children and changed the findNode to use a for loop instead of forEach. In this way we can also break when we find the node and not continue recursing.
As part of the initial sorting we will sort the inputs by parentGroup so we ensure that a childs parent is added in the tree structure before we try to find it with findNode.
I believe this produces the correct result:
inputs.sort((a, b) => (a.parentGroup === "null" ? -1 : 1));
// Sort by parentGroup
let root = inputs.pop();
let inputsDescending = [root];
let max = inputs.length * inputs.length;
let c = 0;
while (inputs.length > 0 && max > c) {
const child = inputs.pop();
const hasParentGroup = inputsDescending.find(
(parent) => parent.groupName === child.parentGroup
);
if (hasParentGroup || child.parentGroup === "null") {
inputsDescending.push(child);
} else {
inputs.unshift(child);
}
}
let rootEle = { name: "root", children: [] };
inputsDescending.forEach((obj) => {
if (obj.parentGroup === "null") {
let child = { name: obj.groupName, children: [] };
rootEle.children.push(child);
} else {
findNode(rootEle, obj);
}
});
function findNode(ele, obj) {
if (ele.name === obj.parentGroup) {
let child = { name: obj.groupName, children: [] };
ele.children.push(child);
return true;
} else {
const c = ele.children.length;
if (c > 0) {
for (let i = 0; c > i; i++) {
const found = findNode(ele.children[i], obj);
if (found) break;
}
}
}
}
const finalArr = rootEle.children;
Now finalArr looks like this:
[
{ "name": "Unassigned", "children": [] },
{
"name": "P1",
"children": [
{
"name": "C1",
"children": [
{ "name": "K1", "children": [] },
{ "name": "K2", "children": [] }
]
},
{
"name": "C2",
"children": [
{ "name": "A2", "children": [] },
{ "name": "A1", "children": [] }
]
}
]
},
{ "name": "F1", "children": [] },
{
"name": "P2",
"children": [
{ "name": "G1", "children": [
{ "name": "GG1", "children": [] }
]
}
]
},
{ "name": "P3", "children": [] }
]

Normalize JSON to a custom schema

I have an array of objects with the following format
var arr = [
{
"productId": "123456",
"productName": "Test Product 1",
"description": [
"This is delicious",
"Suitable for vegetarian"
],
"attributes": {
"internalId": "091283"
"category": "Dairy"
},
"order": 1
}
];
And I am trying to map into something like below
[
[{
{
"name": "productId",
"value": "123456"
},
{
"name": "productName",
"value": "Test Product 1"
},
{
"name": "description",
"value": ["This is delicious", "Suitable for vegetarian"]
},
{
"name": "attributes",
"value": {
{
"name": "internalId",
"value": "091283"
},
{
"name": "category",
"value": "Dairy"
}
}
},
{
"name": "order",
"value": 1
}
}]
]
I tried mapping simple properties before going further and now stuck at getting only the last property of each object in the loop.
Suppose I don't know what are the format of incoming data and how can I normalize the JSON object to the format I want?
normalizeJson = (array) => {
for(i = 0; i < array.length; i++){
normalizedJson[i] = {};
Object.keys(array[i]).forEach(key => {
if (array[i][key] && typeof array[i][key] === "object") {
// normalizeJson(obj[key]);
// console.log(key + ' is object');
return;
} else {
o = {};
o["name"] = key;
o["value"] = array[i][key];
normalizedJson[i] = o;
// normalizedJson[i]["name"] = key;
// normalizedJson[i].value = array[i][key];
// console.log(key);
return;
}
});
}
console.log(normalizedJson);
};
Or is there any library I can use in order to achieve this?

Try this
var obj = [
{
productId: "123456",
productName: "Test Product 1",
description: ["This is delicious", "Suitable for vegetarian"],
attributes: {
internalId: "091283",
category: "Dairy",
},
order: 1,
},
];
function normalizeObject(obj) {
var result = [];
if (Array.isArray(obj)) {
for (let i of obj) {
result.push(normalizeObject(i));
}
} else if (typeof obj == "object") {
for (let i of Object.keys(obj)) {
result.push({ name: i, value: normalizeObject(obj[i]) });
}
} else {
return obj;
}
return result;
}
console.log(JSON.stringify(normalizeObject(obj), null, 2));
This looping method called recursion. Which is loop by calling function itself.

How to fetch parent ids recursively from json strings

{
"id": "1",
"name": "root",
"children": [
{
"id": "1.1",
"name": "Child 1",
"children": [
{
"id": "1.1.1",
"name": "Child 1-1",
"children": [
{
"id": "1-1-1",
"name": "Child 1-1-1",
"children": [
]
}
]
},
{
"id": "1.1.2",
"name": "Child 1-2",
"children": [
]
},
{
"id": "1.1.3",
"name": "Child 1-3",
"children": [
]
}
]
},
{
"id": "1.2",
"name": "Child 2",
"children": [
{
"id": "1.2.1",
"name": "Child 2-2",
"children": [
]
}
]
}
]
}
This is the JSON string as the response. Had to fetch for the parent elements recursively all the parents id.
For instance, input is 1.2.1 then it returns [1.2]
input is 1.1.3 then it returns [1.1, 1]
How can I achieve this?

Just a simple recursion using dfs
const data = JSON.parse('{"id":"1","name":"root","children":[{"id":"1.1","name":"Child 1","children":[{"id":"1.1.1","name":"Child 1-1","children":[{"id":"1-1-1","name":"Child 1-1-1","children":[]}]},{"id":"1.1.2","name":"Child 1-2","children":[]},{"id":"1.1.3","name":"Child 1-3","children":[]}]},{"id":"1.2","name":"Child 2","children":[{"id":"1.2.1","name":"Child 2-2","children":[]}]}]}')
function dfs (target, node) {
if (node.id === target) { return node.id }
if (!node.children) { return false } // we could even skip that line since in your data you seem to have an empty array
const has = node.children.find(c => dfs(target, c))
return has && [node.id].concat(has.id)
}
console.log(dfs('1.2.1', data))
console.log(dfs('1.1.3', data))

You could take an iterative and recursive approach and
chcek if the given data is not an object, then return
check for the id and if found return an empty array, which gets filled by the calling function
iterate children with a short circuit on found and call the function again.
function getParentIds(object, id) {
var ids;
if (!object || typeof object !== 'object') return; // no object
if (object.id === id) return []; // id found
return object.children.some(o => ids = getParentIds(o, id)) // call recursive function
? [...ids, object.id] // if found, take ids
: undefined; // otherwise return falsy
}
var data = { id: "1", name: "root", children: [{ id: "1.1", name: "Child 1", children: [{ id: "1.1.1", name: "Child 1-1", children: [{ id: "1-1-1", name: "Child 1-1-1", children: [] }] }, { id: "1.1.2", name: "Child 1-2", children: [] }, { id: "1.1.3", name: "Child 1-3", children: [] }] }, { id: "1.2", name: "Child 2", children: [{ id: "1.2.1", name: "Child 2-2", children: [] }] }] };
console.log(getParentIds(data, '1.2.1')); // ['1.2']
console.log(getParentIds(data, '1.1.3')); // ['1.1', '1']
console.log(getParentIds(data, 'foo')); // undefined
.as-console-wrapper { max-height: 100% !important; top: 0; }

You would have to parse the complete object to recursively inject the parent ids in child objects. Something like this will do the thing.
function injectParents(data, parents) {
if(!parents) {
parents = [];
}
parents.push(data.id);
data.children.map(child=>{
child.parents = parents;
if(child.children && child.children.length>0) {
child = injectParents(child, Array.from(parents));
}
return child;
});
return data;
}
Then you would normally call it like
const injectedResponse = injectParents(response, null);

you can use
for(let x in arrayName){
//here you can access the json
console.log(arayName(x).id)
}

Is this what are you looking for?
//Input
let input = '1.2.1';
//Data
data = JSON.parse('{"id":"1","name":"root","children":[{"id":"1.1","name":"Child 1","children":[{"id":"1.1.1","name":"Child 1-1","children":[{"id":"1-1-1","name":"Child 1-1-1","children":[]}]},{"id":"1.1.2","name":"Child 1-2","children":[]},{"id":"1.1.3","name":"Child 1-3","children":[]}]},{"id":"1.2","name":"Child 2","children":[{"id":"1.2.1","name":"Child 2-2","children":[]}]}]}')
//Main function start here
function findIdWhereChild(data, input) {
if (data.children?.find(x => x.id == input)) {
return data.id;
}
else {
if (data.children.length > 0) {
for (let i = 0; i < data.children.length; i++) {
let findalResult = findIdWhereChild(data.children[i], input);
if (findalResult) {
return findalResult;
};
};
} else {
return undefined;
}
}
};
//Execution LOGs
console.log(findIdWhereChild(data, input));

Loop through nested array, find specific leaf node by id, and remove it

JSFiddle
I have a nested array with at most 6 levels. The 6th level is called gls, which holds objects of gls from a database. What I need to do is find a specific gl and remove it from the overall array. I'm able to find the specific element with the following function;
const removeFromData = function(nodes, id) {
return nodes.some((node) => {
if (node.gls) {
node.gls.forEach((gl) => {
if (gl.id === id) {
console.log(gl, id);
}
});
} else if (node.children) {
return removeFromData(node.children, id);
}
});
}
However, I'm struggling to actually remove it from the data array. Trying to get the index by doing data.indexOf(gl) obviously returns -1 as it doesn't search through the nested elements. What's the best way to accomplish this?
const id = 1000;
const data = [{
"id": 1, "name": "Node 1", "children": [{
"id": 2, "name": "Node 1.1", "children": [{
"id": 4, "name": "Node 1.1.1", "leaf": true, "children": [], "gls": [{
"id": 1000, "name": "GL1", "code": "0100"
}, {
"id": 1001, "name": "GL2", "code": "0200"
}]
}, {
"id": 5, "name": "Node 1.1.2", "leaf": true, "children": [], "gls": [{
"id": 2000, "name": "GL3", "code": "0300"
}, {
"id": 2001, "name": "GL4", "code": "0400"
}]
}]
}, {
"id": 3, "name": "Node 1.2", "children": [{
"id": 6, "name": "Node 1.2.1", "leaf": true, "children": [], "gls": [{
"id": 3000, "name": "GL5", "code": "0500"
}, {
"id": 3001, "name": "GL6", "code": "0600"
}]
}]
}]
},
{
"id": 7, "name": "Node 2", "children": [{
"id": 8, "name": "Node 2.1", "children": [{
"id": 9, "name": "Node 2.1.1", "leaf": true, "children": [], "gls": [{
"id": 4000, "name": "GL7", "code": "0700"
}, {
"id": 4001, "name": "GL8", "code": "0800"
}]
}]
}]
}
];
let removeFromData = function(nodes, id) {
return nodes.some((node) => {
if (node.gls) {
node.gls.forEach((gl) => {
if (gl.id === id) {
document.querySelector('#target').innerText = `found ${gl.name}, ${gl.id} with needle ${id}`;
}
});
} else if (node.children) {
return removeFromData(node.children, id);
}
});
}
removeFromData(data, id);
<p id="target"></p>

forEach passes three arguments to the callback, the second of which is the index of the entry being visited. So you can use that index with splice (if you want to modify in place):
const removeFromData = function(nodes, id) {
return nodes.some((node) => {
if (node.gls) {
node.gls.forEach((gl, index) => {
// -----------------------^^^^^^^
if (gl.id === id) {
//console.log(gl, id);
node.gls.splice(index, 1); // <=== Removes the entry
}
});
} else if (node.children) {
return removeFromData(node.children, id);
}
});
}
I notice you're using some, which suggests you want to stop when you've found the entry and perhaps also return a flag indicating success/failure. If so, I'd use some instead of forEach on the nodes.gls search or possibly use findIndex instead. With some:
const removeFromData = function(nodes, id) {
return nodes.some((node) => {
if (node.gls) {
return node.gls.some((gl, index) => {
if (gl.id === id) {
//console.log(gl, id);
node.gls.splice(index, 1); // <=== Removes the entry
return true;
}
});
} else if (node.children) {
return removeFromData(node.children, id);
}
});
}
With findIndex:
const removeFromData = function(nodes, id) {
return nodes.some((node) => {
if (node.gls) {
const index = node.gls.findIndex((gl) => {
return gl.id === id;
});
if (index === -1) {
return false;
}
node.gls.splice(index, 1);
return true;
} else if (node.children) {
return removeFromData(node.children, id);
}
});
}

Effective ways to check if the given ID exist inside nested objects in Javascript

What is the best way to check if the given ID exist inside nested objects in JavaScript.
Object
campusElement = {
"id": "C1",
"name": "camp",
"buildings": [{
"id": "B1",
"name": "B-name",
"floors": [{
"id": "F1",
"name": "F-name",
"rooms": [{
"id": "R1",
"name": "R-name"
}]
}]
}]
}
currently I'm looping through entire objects and doing
component.ts
isIdExists(elementID: string) {
var isIdUnique = false;
if (campusElement.id === elementID) {
isIdUnique = true;
} else {
for (const building of campusElement.buildings) {
if (building.id === elementID) {
isIdUnique = true;
break;
} else {
for (const floor of building.floors) {
if (floor.id === elementID) {
isIdUnique = true;
break;
} else {
for (const room of floor.rooms) {
if (room.id === elementID) {
isIdUnique = true;
break;
}
}
}
}
}
}
}
return isIdUnique;
}
is there a better way to do this?

"Best" is subjective, but you could write a generic recursive function that looks for a property with a specified name and value, and if it doesn't find it at the top level iterate over all properties to check for any that are arrays and if so check each of the array elements recursively:
function propertyExists(obj, propName, propValue) {
if (obj[propName] === propValue)
return true
for (var k in obj) {
if (Array.isArray(obj[k]) && obj[k].some(function(v) {
return typeof v === "object" && propertyExists(v, propName, propValue)
})) {
return true
}
}
return false
}
campusElement = {
"id": "C1",
"name": "camp",
"buildings": [{
"id": "B1",
"name": "B-name",
"floors": [{
"id": "F1",
"name": "F-name",
"rooms": [{
"id": "R1",
"name": "R-name"
}]
}]
}]
}
console.log(propertyExists(campusElement, "id", "C1")) // true
console.log(propertyExists(campusElement, "id", "R1")) // true
console.log(propertyExists(campusElement, "name", "R-name")) // true
console.log(propertyExists(campusElement, "id", "no matching value")) // false
console.log(propertyExists(campusElement, "no matching prop name", "C1")) // false
console.log(propertyExists(campusElement, "rooms", "X1")) // false

now I am doing this this using java script "includes"
findIfIdExists(object, key, value){
return JSON.stringify(object).includes('"'+key+'":"'+value+'"');
}
and
console.log(findIfIdExists(campusElement, 'id', 'C1')); //true