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how to populate tree from flatTreeNode?

I have treeFlatNode array i want to structure it in tree format. or can i display this array in tree directly in angular.
data=[
{
expandable: true
level: 0
name: "2021-12-31"
path: null
},
{
expandable: false
level: 2
name: "A.txt"
path: "2021-12-31/B/C/A.txt"
}
]
required format
tree=[
name:"2021-12-03",
children:[
name:"B",
children:[{
name:"C"
children:[{
name:"A.txt"
children:[]
}]
}]
]
]

You could use an object (map) that maps a (sub)path to a node in the final tree. If it doesn't exist yet, it is added to the parent's children.
As your tree structure actually represents a forest (there can be multiple roots), I would name the result variable forest instead of tree
Snippet:
function toForest(data) {
const roots = [];
const map = {};
for (const obj of data) {
let key = "";
let children = roots;
for (const name of (obj.path ?? obj.name).split("/")) {
let child = map[key += "/" + name];
if (!child) children.push(map[key] = child = { name, children: [] });
({children} = child);
}
}
return roots;
}
// Example run
let data = [{expandable: true,level: 0,name: "2021-12-31",path: null}, {expandable: false,level: 2,name: "A.txt",path: "2021-12-31/B/C/A.txt"}];
let forest = toForest(data);
console.log(forest);

So, to transform your data structure to the desired one, you can use following function (with comments =) ):
transform(data){
const tree = [];
for (let node of data) {
// If there's no path it's a parent node
// but add it only if it doesn't exist yet
if (node.path === null && tree.every(n => n.name !== node.name)) {
tree.push({ name: node.name, children: [] });
continue;
}
// Extract name of parent node and other nodes
const [parentNodeName, ...pathElems]: string[] = node.path.split('/');
// Look-up for the parent node
let parentNode = tree.find(t => t.name === parentNodeName);
// If parent doesn't exist yet, so we create it here
if (!parentNode) {
parentNode = { name: parentNodeName, children: [] }
}
let children = parentNode.children;
// If the level of the node is relevant
// otherwise simply iterate over all pathElems
for(let i = 0; i <= node.level; i ++) {
let child = children.find(c => c.name === pathElems[i]);
// If the child doesn't exist yet - create it
if (!child) {
child = {
name: pathElems[i],
children: []
}
children.push(child);
children = child.children;
continue;
}
// Child does exist, so use it's children for the next iteration
children = child.children;
}
}
return tree;
}
And you can call this function, for example, in ngOnInit:
ngOnInit() {
this.tree = this.transform(this.data);
}

I do not use Angular, but if you just need to convert your flat to nested:
var data = [
{
expandable: true,
level: 0,
name: "2021-12-31",
path: null
},
{
expandable: false,
level: 2,
name: "A.txt",
path: "2021-12-31/B/C/A.txt"
}
]
var to_nested = function(flat) {
var nested = []
var cache = {}
var l = flat.length
var cache_assert = function(name) {
if (cache[name] == null) {
cache[name] = {
name: name,
children: []
}
}
}
for (var i = 0; i < l; i++) {
var current_node = flat[i]
cache_assert(current_node.name)
if (current_node.path == null) {
nested.push(cache[current_node.name])
} else {
var names = current_node.path.split("/")
var parent_name = names.shift()
cache_assert(parent_name)
names.forEach(function(name) {
cache_assert(name)
cache[parent_name].children.push(cache[name])
parent_name = name
})
}
}
return nested
}
var a = to_nested(data)
console.log('a: ', a)
console.log('a: ', a[0].children)
console.log('a: ', a[0].children[0].children)
And if you want to return to flat:
var level = 0
var cache = []; cache[level] = a.slice(0)
var parent = []; parent[level] = null
var index = []; index[level] = 0
while (level >= 0) {
var node = cache[level][index[level]]
if (node != null) {
console.log('node: ', node)
if (
node['children'] != null &&
Object.prototype.toString.call(node['children']) === '[object Array]' &&
node['children'].length
) {
level++
index[level] = 0
parent[level] = Object.assign({}, node)
delete parent[level]['children']
cache[level] = node['children'].slice(0)
} else {
index[level]++
}
} else {
parent[level] = null
level--
index[level]++
}
}

How to change the object depending value type javascript?

How to change the nested object to new object in javascript.
I have a object obj in which if details is arrays, then take first array value as value in javascript.
function newObj(obj1) {
let map = {};
obj1.forEach(e => {
let details = e.details;
Object.values(details).forEach(value => {
if (Array.isArray(value) && value.length > 0) {
map[value[0]] = value[0];
}
else if (typeof value === 'object') {
Object.values(value).forEach(val => { map[val] = val; });
}
})
});
return map;
}
var obj1 = [
{
details : {
"info" : ["stocks", "finance", ""],
"sales" : ["analytics"]
}
}
];
var obj2 = [
{
details : {
"city" : "SG"
}
}
];
var r1 = this.newObj(obj1);
var r2 = this.newObj(obj2);
Expected Output
//for obj1 (show only first value of array)
{
info : "stocks",
sales : "analytics"
}
//obj2
{
city : "SG"
}

I think you have overcomplicated this. Look at the example below. The logic goes like this:
Iterate over details keys
If a value under the key is an array, then create the key in the map and assign the value[0]
If a value under the key is not an array, then simply copy its value into the map
And that's enough to achieve what you want.
function newObj(obj){
let map = {};
obj.forEach(e => {
let details = e.details;
Object.keys(details).forEach(key => {
var value = details[key];
if (Array.isArray(value) && value.length > 0){
map[key] = value[0];
} else {
map[key] = value;
}
});
});
return map;
}
var obj1 = [
{
details: {
"info":["stocks","finance",""],
"sales":["analytics"]
}
}
];
var obj2 = [
{
details: {
"city":"SG"
}
}
];
var r1 = newObj(obj1);
var r2 = newObj(obj2);
console.log(r1);
console.log(r2);

Here's a very concise solution thanks to destructuring assignments:
function newObj(obj) {
const [{ details }] = obj;
const entries = Object.entries(details)
.map(([key, value]) => ([key, Array.isArray(value) ? value[0] : value]));
return Object.fromEntries(entries);
}
Live example:
'use strict';
function newObj(obj) {
const [{ details }] = obj;
const entries = Object.entries(details)
.map(([key, value]) => ([key, Array.isArray(value) ? value[0] : value]));
return Object.fromEntries(entries);
}
const obj1 = [
{
details: {
info: ['stocks', 'finance', ''],
sales: ['analytics']
}
}
];
const obj2 = [
{
details: {
city: 'SG'
}
}
];
console.log(newObj(obj1));
console.log(newObj(obj2));

How to update async await function when a variable change?

genderPie()
let filter = {};
async function genderPie() {
const d = await getData();
const g = await d.reduce((a, o) => (o.GEN && a.push(o.GEN), a), []);
const gender = Object.keys(g).length;
const m = await d.reduce((a, o) => (o.GEN == 1 && a.push(o.GEN), a), []);
const male = Object.keys(m).length;
const f = await d.reduce((a, o) => (o.GEN == 2 && a.push(o.GEN), a), []);
const female = Object.keys(f).length;
var data = [{
name: 'male',
y: male,
id: 1
}, {
name: 'female',
y: female,
id: 2
}];
chart = new Highcharts.Chart({
plotOptions: {
pie: {
innerSize: '80%',
dataLabels: {
connectorWidth: 0
}
}
},
series: [{
"data": data,
type: 'pie',
animation: false,
point: {
events: {
click: function(event) {
filter.GEN = '' + this.id + '';
}
}
}
}],
"chart": {
"renderTo": "gender"
},
});
}
async function getData() {
buildFilter = (filter) => {
let query = {};
for (let keys in filter) {
if (filter[keys].constructor === Array && filter[keys].length > 0) {
query[keys] = filter[keys];
}
}
return query;
}
//FILTER DATA
//Returns the filtered data
filterData = (dataset, query) => {
const filteredData = dataset.filter((item) => {
for (let key in query) {
if (item[key] === undefined || !query[key].includes(item[key])) {
return false;
}
}
return true;
});
return filteredData;
};
//FETCH JSON
const dataset = [{
"GEN": "2"
}, {
"GEN": "1"
}, {
"GEN": "1"
}, {
"GEN": "2"
},
{
"GEN": "2"
}, {
"GEN": "2"
}, {
"GEN": "2"
}, {
"GEN": "1"
}
]
//BUILD THE FILTER
const query = buildFilter(filter);
const result = filterData(dataset, query);
console.log(result)
return result
}
<script src="https://code.highcharts.com/highcharts.js"></script>
<div id="gender"></div>
does anyone can explain me how to handle the following?
I have two functions that filter data and than I build a chart with Hichart
Each time a user click for example a slice of a pie chart an event is fired and an object is populated.
That object allows me to filter the dataset and redraw the chart
The last thing I'm missing is about to update the filtering functions based on the object to be populated
first I'll do this
async function getData() {
buildFilter = (filter) => {
let query = {};
for (let keys in filter) {
if (filter[keys].constructor === Array && filter[keys].length > 0) {
query[keys] = filter[keys];
}
}
return query;
}
then
filterData = (data, query) => {
const filteredData = data.filter( (item) => {
for (let key in query) {
if (item[key] === undefined || !query[key].includes(item[key])) {
return false;
}
}
return true;
});
return filteredData;
};
const query = buildFilter(filter);
const result = filterData(data, query);
my object is
let filter = {}
when a user click the slice myobject become for example
let filter = {
gen: "1"
}

Take a look at this StackBlitz project.
In getData(), I simplified your filter to this one:
return data.filter(item => {
for (const property of Object.keys(filter)) {
if (item[property] !== filter[property]) {
return false;
}
}
return true;
});
and when a slice is clicked, I call genderPie() again, after updating the filter.
You might want to separate the data request from the filtering, so that the data is downloaded only once, not every time a filter is changed.

restructure json based on parent

I am studying the use of reduce in javascript, and I am trying to restructure an Array of Objects in a generic way - need to be dynamic.
flowchart - i get totaly lost
I started with this through.
Every ID becomes a Key.
Every PARENT identifies which Key it belongs to.
i have this:
const in = [
{
"id": "Ball",
"parent": "Futebol"
},
{
"id": "Nike",
"parent": "Ball"
},
{
"id": "Volley",
"parent": null
}
]
i want this
out = {
"Futebol": {
"Ball": {
"Nike": {}
}
},
"Volley": {}
}
i try it - and i had miserably failed.
const tree = require('./mock10.json')
// Every ID becomes a Key.
// Every PARENT identifies which Key it belongs to.
const parsedTree = {}
tree.reduce((acc, item) => {
if (parsedTree.hasOwnProperty(item.parent)){
if (parsedTree[`${item.parent}`].length > 0) {
parsedTree[`${item.parent}`][`${item.id}`] = {}
} else {
parsedTree[`${item.parent}`] = { [`${item.id}`]: {} }
}
} else {
// i get lost in logic
}
}, parsedTree)
console.log(parsedTree)

Got a working code for you, feel free to ask me about the implementation
Hope it helps :)
const arrSample = [
{
"id": "Ball",
"parent": "Futebol"
},
{
"id": "Nike",
"parent": "Ball"
},
{
"id": "Volley",
"parent": null
}
]
const buildTree = (arr) => {
return arr.reduce(([tree, treeMap], { id, parent }) => {
const val = {}
treeMap.set(id, val)
if (!parent) {
tree[id] = val
return [tree, treeMap]
}
if (!treeMap.has(parent)) {
const parentVal = { [id]: val }
treeMap.set(parent, parentVal)
tree[parent] = parentVal
return [tree, treeMap]
}
const newParentValue = treeMap.get(parent)
newParentValue[id] = val
treeMap.set(parent, newParentValue)
return [tree, treeMap]
}, [{}, new Map()])
}
const [result] = buildTree(arrSample)
console.log(JSON.stringify(result, 0, 2))

You could use reduce method for this and store each id on the first level of the object. This solution will work if the objects in the array are in the correct order as in the tree structure.
const data = [{"id":"Futebol","parent":null},{"id":"Ball","parent":"Futebol"},{"id":"Nike","parent":"Ball"},{"id":"Volley","parent":null}]
const result = data.reduce((r, { id, parent }) => {
if (!parent) {
r[id] = {}
r.tree[id] = r[id]
} else if (r[parent]) {
r[parent][id] = {}
r[id] = r[parent][id]
}
return r
}, {tree: {}}).tree
console.log(result)

If reduce solution is just an option, you can try this way:
var input = [
{
"id": "Ball",
"parent": "Futebol"
},
{
"id": "Nike",
"parent": "Ball"
},
{
"id": "Volley",
"parent": null
}
];
var output = {};
input.forEach(item => {
var temp = input.find(x => x.id === item.parent);
if (temp) {
temp[item.id] = {};
}
});
input = input.filter(item => !input.find(x => x.hasOwnProperty(item.id)));
input.forEach(item => {
if (!item.parent) {
output[item.id] = {};
} else {
for (var [id, value] of Object.entries(item)) {
if (typeof value === 'object') {
output[item.parent] = { [item.id]: { id: {} } };
}
}
}
})
console.log(output);

I have tried many things, but none works if we use an Array.prototype.reduce
As there are missing parents, and the elements are out of order, plus the fact that there can be an infinity of levels, I really do not believe that this question can be resolved with a simple reduce
This code should work whatever the cases :
- if all parents are not declared
- if there are infinitely many levels
- if they are in disorder
const origin =
[ { id: 'Ball', parent: 'Futebol' }
, { id: 'Nike', parent: 'Ball' }
, { id: 'Volley', parent: null }
, { id: 'lastOne', parent: 'level4' } // added
, { id: 'level4', parent: 'Nike' } // added
, { id: 'bis', parent: 'Nike' } // added
];
const Result = {} // guess who ?
, Parents = [] // tempory array to keep parents elements address by key names
;
let nbTodo = origin.length // need this one to verify number of elements to track
;
// set all the first levels, add a todo flags
origin.forEach(({id,parent},i,ori)=>
{
ori[i].todo = true // adding todo flag
if (parent===null)
{
Result[id] = {} // new first level element
ori[i].todo = false // one less :)
nbTodo--
Parents.push(({ref:id,path:Result[id]}) ) // I know who you are!
}
else if (origin.filter(el=>el.id===parent).length===0) // if he has no parent...
{
Result[parent] = {} // we create it one
Parents.push({ref:parent,path:Result[parent]} )
}
})
// to put the children back in their parents' arms
while(nbTodo>0) // while there are still some
{
origin.forEach(({id,parent,todo},i,ori)=> // little by little we find them all
{
if(todo) // got one !
{
let pos = Parents.find(p=>p.ref===parent) // have parent already been placed?
if(pos)
{
ori[i].todo = false // to be sure not to repeat yourself unnecessarily
nbTodo-- // one less :)
pos.path[id] = {} // and voila, parentage is done
Parents.push(({ref:id,path:pos.path[id]}) ) // he can now take on the role of parent
}
}
})
}
for (let i=origin.length;i--;) { delete origin[i].todo } // remove todo flags
console.log( JSON.stringify(Result, 0, 2) )
.as-console-wrapper { max-height: 100% !important; top: 0; }
I finaly made this one, based on this previous on, and done with a first step by a reduce...
to by pass the Array of Parents, I made a recursive function for searching each parent elements thru the levels of parsedTree result.
here is the code:
const Tree =
[ { id: 'Ball', parent: 'Futebol' }
, { id: 'Nike', parent: 'Ball' }
, { id: 'Volley', parent: null }
, { id: 'lastOne', parent: 'level4' } // added
, { id: 'level4', parent: 'Nike' } // added
, { id: 'bis', parent: 'Nike' } // added
];
const parsedTree = Tree.reduce((parTree, {id,parent},i ) => {
Tree[i].todo = false
if (parent===null)
{ parTree[id] = {} }
else if (Tree.filter(el=>el.id===parent).length===0) // if he has no parent...
{ parTree[parent] = { [id]: {} } }
else
{ Tree[i].todo = true }
return parTree
}, {})
function parsedTreeSearch(id, part) {
let rep = null
for(let kId in part) {
if (kId===id)
{ rep = part[kId] }
else if (Object.keys(part[kId]).length)
{ rep = parsedTreeSearch(id, part[kId]) }
if (rep) break
}
return rep
}
while (Boolean(Tree.find(t=>t.todo))) {
Tree.forEach(({id,parent,todo},i)=>{ // little by little we find them all
if (todo) {
let Pelm = parsedTreeSearch(parent, parsedTree)
if (Boolean(Pelm)) {
Pelm[id] = {}
Tree[i].todo = false
} } }) }
for (let i=Tree.length;i--;) { delete Tree[i].todo } // remove todo flags
console.log( JSON.stringify( parsedTree ,0,2))
.as-console-wrapper { max-height: 100% !important; top: 0; }

Recursively find keys on an object

I have a javascript object structured like this;
brand: {
group: {
subGroup: {
items: []
},
otherSub: {
items: []
}
}
}
Given an array of keys ['brand', 'group', 'newGroup', 'newSubGroup'] I want to split the keys into found and missing keys. So for the structure above I should get back;
present = ['brand', 'group']
missing = ['newGroup', 'newSubGroup']
I'm using ES6 and have lodash available, but struggling to find a clean way to produce this.
This is not to just check existence, it's recursively find the keys and return those present and the remaining ones.

Here's a pretty sketchy way that works.
const find = (keys, obj) => {
const string = JSON.stringify(obj);
return keys.reduce(({ present, missing }, key) => {
const match = string.match(new RegExp(`"${key}":`));
if (match) {
present.push(key);
} else {
missing.push(key);
}
return { present, missing };
}, { present: [], missing: [] });
}

You can use this function made for you ;)
var getAttrs = function(obj) {
return [].concat.apply([], Object.keys(obj).map(function (key) {
var results = [key]
if (typeof obj[key] === 'object') {
Array.prototype.push.apply(results, getAttrs(obj[key]))
}
return results
}))
}
It return the list of properties and children properties.
getAttrs({brand: {
group: {
subGroup: {
items: []
},
otherSub: {
items: []
}
}
}})
> ["brand", "group", "subGroup", "items", "otherSub", "items"]
And you can use it like so:
var lookingFor = ['brand', 'group', 'newGroup', 'newSubGroup']
var existings = getAttrs(obj)
var missings = []
var presents = []
lookingFor.forEach(attr => {
if (existings.indexOf(attr) === -1) {
missings.push(attr)
} else {
presents.push(attr)
}
})

I wrote a function to recursively get unique keys from a nested object, then filtered the array of all the keys you mentioned checking which were present in the result of my function.
var thisObject = {
brand: {
group: {
subGroup: {
items: []
},
otherSub: {
items: []
}
}
}
};
var arr_full = ['brand', 'group', 'newGroup', 'newSubGroup'] ;
var key_array = [];
function addToKeyArray( key_array, object ){
for( var key in object ){
// only get unique keys
if( key_array.indexOf( key ) === -1 ){
key_array.push( key );
}
// concat the result of calling this function recurrsively on object[key]
key_array.concat( addToKeyArray( key_array, object[key] ) );
}
return key_array;
}
var test = addToKeyArray( [], thisObject );
var missing = arr_full.filter( function( el ) {
return test.indexOf( el ) < 0;
});
console.log( test );
console.log( missing )

You can create recursive function using for...in loop inside another function and return object as result..
var obj = {"brand":{"group":{"subGroup":{"items":[]},"otherSub":{"items":[]}}}}
var keys = ['brand', 'group', 'newGroup', 'newSubGroup'] ;
function findKeys(data, keys) {
keys = keys.slice();
function findPresent(data, keys) {
var result = []
for(var i in data) {
if(typeof data[i] == 'object') result.push(...findPresent(data[i], keys))
var index = keys.indexOf(i);
if(index != -1) result.push(...keys.splice(index, 1))
}
return result
}
return {present: findPresent(data, keys), missing: keys}
}
console.log(findKeys(obj, keys))

To keep things clean and readable you can use "for in", inside a nested function for your recursion.
function recur(obj) {
let preMiss = {
present: [],
missing: []
}
let root = traverse => {
for (let key in traverse) {
if (Array.isArray(traverse[key].items)) {
preMiss.missing.push(key);
}
if (typeof traverse[key] === 'object' && !Array.isArray(traverse[key].items)) {
preMiss.present.push(key);
root(traverse[key])
}
}
}
root(obj);
return preMiss;
}
const object = {
brand: {
group: {
subGroup: {
items: []
},
otherSub: {
items: []
}
}
}
}
console.log(Object.entries(recur(object)));

var toFind = ['brand', 'group', 'newGroup', 'newSubGroup'],
found = [];
var o = {
brand: {
group: {
subGroup: {
items: []
},
otherSub: {
items: []
}
}
}
}
//called with every property and its value
function process(key,value) {
var i = toFind.indexOf(key);
if(i !== -1){
found.push(key);
toFind.splice(i, 1);
}
}
function traverse(o,func) {
if(!toFind.length) return;
for (var i in o) {
func.apply(this,[i,o[i]]);
if (o[i] !== null && typeof(o[i])=="object") {
//going one step down in the object tree!!
traverse(o[i],func);
}
}
}
traverse(o,process);
console.log(found); // present
console.log(toFind); // absent
Traverse method taken from https://stackoverflow.com/a/722732/1335165

Even though this question is a bit older, I want to present a rather short solution to the problem.
const recursivelyGetKeys = obj => Object.keys(obj).map(key => typeof obj[key] === 'object'
? [...recursivelyGetKeys(obj[key]), key] : [key]).reduce((p, c) => [...p, ...c], [])
This function will return all keys in the object, so a call to the array arr with
const arr = {
brand: {
group: {
subGroup: {
items: []
},
otherSub: {
items: []
}
}
}
}
will output:
const keys = recursivelyGetKeys(arr) // = ["items", "subGroup", "items", "otherSub", "group", "brand"]
Now to find the intersection set of this and find = ['brand', 'group', 'newGroup', 'newSubGroup'], do:
const found = keys.filter(key => find.some(val === key))
const missing = keys.filter(key => find.every(val !== key))