Hi I have a function that takes nested array of parents containing children and flatten it. However, I would like to also keep track of all of its higher nodes ids.
Example data structure:
[{ id: 1, type: "group", name: "Colors", items: [ { id: 2, type: "item", name: "Red", items: [] }, { id: 3, type: "item", name: "Purple2", items: [] }, { id: 4, type: "item", name: "Black", items: [ { id: 5, type: "item", name: "Purple3", items: [], }, { id: 6, type: "item", name: "Purple4", items: [] }, ], }, ], }] This is current end result (this is exactly what I want to achieve), but potentially functions below can be refactored.
{id: 1, name: "Colors", depth: 1, parentId: null, main: []} 1: {id: 2, name: "Red", depth: 2, parentId: 1, main: [1]} 2: {id: 3, name: "Purple2", depth: 2, parentId: 1, main: [1]} 3: {id: 4, name: "Black", depth: 2, parentId: 1, main: [1]} 4: {id: 5, name: "Purple3", depth: 3, parentId: 4, main: [1,4]} // main stores id of all higher parents e.g. id 4 = "black" and parent of 4 = "Colors" 5: {id: 6, name: "Purple4", depth: 3, parentId: 4, main: [1,4]} My current flatten array function:
const flattenArr = (data, depth = 1, parent = null) => { const result = []; data.forEach((item) => { const { id, name, items } = item; result.push({ id, name, depth, parentId: parent, main: [], }); if (items) result.push(...flattenArr(items, depth + 1, item.id)); }); return result; }; The function below is used to keep track of all parent ids. However it does not seem to be most optimal solution that I can use therefore I would like to know whether it can be improved possibly to be done all in one recursive function.
const collectParents = (arr) => { for (let b = 0; b < arr.length; b++) { if (arr[b].depth !== 1) { arr[b].main.push( ...arr[b - 1].main, arr[b - 1].depth === arr[b].depth - 1 ? arr[b - 1].id : null ); } } arr.forEach((x) => (x.main = x.main.filter((i) => i !== null))); }; 
