I am trying to create a category tree using the array of json objects below.
I want to set a category as a child of another category if its parent equals the id of the other, and I want the posts also to be a children of that category instead of having a separate field for posts, I'll add a flag field that if it is a category or not isParent.
It looks like its working alright, but as you may see, if a category has both category and post as child, it'll only show the categories. Another problem with that is if the post has a null value on its array, it will still push them as children.
What are the mistakes in my code, or is there a simpler or better solution to this?
var tree = unflatten(getData());
var pre = document.createElement('pre');
console.log(tree);
pre.innerText = JSON.stringify(tree, null, 4);
document.body.appendChild(pre);
function unflatten(array, parent, tree) {
tree = typeof tree !== 'undefined' ? tree : [];
parent = typeof parent !== 'undefined' ? parent : {
id: 0
};
_.map(array, function(arr) {
_.set(arr, 'isParent', true);
});
var children = _.filter(array, function(child) {
return child.parent == parent.id;
});
if (!_.isEmpty(children)) {
if (parent.id == 0) {
tree = children;
} else {
parent['children'] = children;
}
_.each(children, function(child) {
var posts = _.map(child.posts, function(post) {
return _.set(post, 'isParent', false);
});
child['children'] = posts;
delete child.posts;
unflatten(array, child);
});
}
return tree;
}
function getData() {
return [{
"id": "c1",
"parent": "",
"name": "foo",
"posts": [{
"id": "p1"
}]
}, {
"id": "c2",
"parent": "1",
"name": "bar",
"posts": [{
"id": "p2"
}]
}, {
"id": "c3",
"parent": "",
"name": "bazz",
"posts": [
null
]
}, {
"id": "c4",
"parent": "3",
"name": "sna",
"posts": [{
"id": "p3"
}]
}, {
"id": "c5",
"parent": "3",
"name": "ney",
"posts": [{
"id": "p4"
}]
}, {
"id": "c6",
"parent": "5",
"name": "tol",
"posts": [{
"id": "p5"
}, {
"id": "p6"
}]
}, {
"id": "c7",
"parent": "5",
"name": "zap",
"posts": [{
"id": "p7"
}, {
"id": "p8"
}, {
"id": "p9"
}]
}, {
"id": "c8",
"parent": "",
"name": "quz",
"posts": [
null
]
}, {
"id": "c9",
"parent": "8",
"name": "meh",
"posts": [{
"id": "p10"
}, {
"id": "p11"
}]
}, {
"id": "c10",
"parent": "8",
"name": "ror",
"posts": [{
"id": "p12"
}, {
"id": "p13"
}]
}, {
"id": "c11",
"parent": "",
"name": "gig",
"posts": [{
"id": "p14"
}]
}, {
"id": "c12",
"name": "xylo",
"parent": "",
"posts": [{
"id": "p15"
}]
}, {
"id": "c13",
"parent": "",
"name": "grr",
"posts": [{
"id": "p16"
}, {
"id": "p17"
}, {
"id": "p14"
}, {
"id": "p18"
}, {
"id": "p19"
}, {
"id": "p20"
}]
}]
}
<script src="//cdn.jsdelivr.net/lodash/3.10.1/lodash.min.js"></script>
Expected Output
So the expected output will be more like:
[
{
id: 'c1',
isParent: true,
children: [
{
id: 'c2',
isParent: true,
children: []
},
{
id: 'p1'
isParent: false
}
]
}
]
And so on..
Your code is very imperative. Try focusing on the "big picture" of data flow instead of writing code by trial-and-error. It's harder, but you get better results (and, in fact, usually it's faster) :)
My idea is to first group the categories by their parents. This is the first line of my solution and it actually becomes much easier after that.
_.groupBy and _.keyBy help a lot here:
function makeCatTree(data) {
var groupedByParents = _.groupBy(data, 'parent');
var catsById = _.keyBy(data, 'id');
_.each(_.omit(groupedByParents, ''), function(children, parentId) {
catsById['c' + parentId].children = children;
});
_.each(catsById, function(cat) {
// isParent will be true when there are subcategories (this is not really a good name, btw.)
cat.isParent = !_.isEmpty(cat.children);
// _.compact below is just for removing null posts
cat.children = _.compact(_.union(cat.children, cat.posts));
// optionally, you can also delete cat.posts here.
});
return groupedByParents[''];
}
I recommend trying each part in the developer console, then it becomes easy to understand.
I have made a small fidde that I think that is what you want.
http://jsfiddle.net/tx3uwhke/
var tree = buildTree(getData());
var pre = document.getElementById('a');
var jsonString = JSON.stringify(tree, null, 4);
console.log(jsonString);
pre.innerHTML = jsonString;
document.body.appendChild(pre);
function buildTree(data, parent){
var result = [];
parent = typeof parent !== 'undefined' ? parent : {id:""};
children = _.filter(data, function(value){
return value.parent === parent.id;
});
if(!_.isEmpty(children)){
_.each(children, function(child){
if (child != null){
result.push(child);
if(!_.isEmpty(child.posts)){
var posts = _.filter(child.posts, function(post){
return post !== null && typeof post !== 'undefined';
});
if(!_.isEmpty(posts)){
_.forEach(posts, function(post){
post.isParent = false;
});
}
result = _.union(result, posts);
delete child.posts;
}
ownChildren = buildTree(data, child);
if(!_.isEmpty(ownChildren)){
child.isParent = true;
child.children = ownChildren;
}else{
child.isParent = false;
}
}
});
}
return result;
}
EDIT: made a new fiddle to contain the isParent part you can find it here
While this problem looks simple, I can remember to have struggled achieving it in a simple way. I therefore created a generic util to do so
You only have to write maximum 3 custom callbacks methods.
Here is an example:
import { flattenTreeItemDeep, treeItemFromList } from './tree.util';
import { sortBy } from 'lodash';
const listItems: Array<ListItem> = [
// ordered list arrival
{ id: 1, isFolder: true, parent: null },
{ id: 2, isFolder: true, parent: 1 },
{ id: 3, isFolder: false, parent: 2 },
// unordered arrival
{ id: 4, isFolder: false, parent: 5 },
{ id: 5, isFolder: true, parent: 1 },
// empty main level folder
{ id: 6, isFolder: true, parent: null },
// orphan main level file
{ id: 7, isFolder: false, parent: null },
];
const trees = treeItemFromList(
listItems,
(listItem) => listItem.isFolder, // return true if the listItem contains items
(parent, leafChildren) => parent.id === leafChildren.parent, // return true if the leaf children is contained in the parent
(parent, folderChildren) => parent.id === folderChildren.parent // return true if the children is contained in the parent
);
console.log(trees);
/*
[
{
children: [
{
children: [{ data: { id: 3, isFolder: false, parent: 2 }, isLeaf: true }],
data: { id: 2, isFolder: true, parent: 1 },
isLeaf: false,
},
{
children: [{ data: { id: 4, isFolder: false, parent: 5 }, isLeaf: true }],
data: { id: 5, isFolder: true, parent: 1 },
isLeaf: false,
},
],
data: { id: 1, isFolder: true, parent: null },
isLeaf: false,
},
{ children: [], data: { id: 6, isFolder: true, parent: null }, isLeaf: false },
{
data: {
id: 7,
isFolder: false,
parent: null,
},
isLeaf: true,
},
]
*/
I did not check with your example as all cases are different, you however need to implement only 3 methods to let the algorithm build the tree for you:
If the item is a folder or a leaf (in your case just check if the children contain any non falsy item) i.e. listItem.posts.some((value)=>!!value)
if a parent contains the leaf child, (parent, child) => !!parent.posts.filter((val)=>!!val).find(({id})=>child.id === id)
if a parent contains the folder: optional if this is the same logic as for a leaf child.
Related
I am trying to delete an object in a nested object(hierarchical) array with a parent-child relationship. I want to delete an object from this which has the attribute 'required' as false and 'name' is empty or null. When I delete this object, if it is a parent object, I want the children to be attached to the grandparent (parent's parent object). But when I delete it in recursion, the whole element including the child gets deleted. Please help with the recursive approach.
The following is the structure
{
"name": "abc",
"nodeId": 1,
"parentNodeId": null,
"required": true,
"children": [
{
"name": "",
"nodeId": 2,
"parentNodeId": 1,
"required": false,
"children": [
{
"name": "",
"nodeId": 3,
"parentNodeId": 2,
"required": false,
"children": [
{
"name": "xyz",
"nodeId": 4,
"parentNodeId": 3,
"required": true,
"children": []
}
]
},
{
"name": "pqr",
"nodeId": 5,
"parentNodeId": 2,
"required": true,
"children": []
}
]
}
]
}
In the above scenario, the child with name 'xyz' should directly be attached to the nodeId of 1 (abc) as its immediate parents are to be deleted.
I have found this particular solution for deletion based on given condition, but it doesn't retain the child elements.
removeFromTree(root, parent, idx) {
if (!root.name && root.required === false) {
if (parent) {
parent.modelLines.splice(idx, 1);
}
else return null;
}
if (root.modelLines != null) {
for (const [i, e] of root.children.entries()) {
this.removeFromTree(e, root, i);
}
}
return tree;
};
Please help to address this scenario
You can use the below code snippet to achieve your requirement:
removeFromTree = function(node) {
var childrenHolder = []
var accumulator = []
for(const [i, child] of node.children.entries()) {
var holder = removeFromTree(child);
if (child.name || child.required === true) {
childrenHolder.push(child)
}
else {
accumulator = [...accumulator, ...holder]
}
}
node.children = [...childrenHolder,...accumulator]
for( var [i, child] of node.children.entries()) {
child.parentNodeId = node.nodeId
}
return node.children
}
let data = {
"rec": [{
"id": "25837",
"contentId": "25838"
},
{
"id": "25839",
"contentId": "25838"
},
{
"id": "25838"
},
{
"id": "25636",
"contentId": "25837"
}, {
"id": "25640",
"contentId": "25839"
}
]
};
I have a javascript object which I have to manipulate to below format.
{
"childern": [{
"id": "25838",
"childern": [{
"id": "25837",
"contentId": "25838",
"childern": [{
"id": "25636",
"contentId": "25837"
}]
},
{
"id": "25839",
"contentId": "25838",
"childern": [{
"id": "25640",
"contentId": "25839"
}]
}
]
}]
}
If any object dont have contentId it should be at parent level. then all the objects having contentId same as parent id should be at its child level and so on.
I have created a fiddle here but logic is not completed. Any idea or reference to achieve this.
You could create recursive function with reduce method to get the desired result.
let data = {"rec":[{"id":"25837","contentId":"25838"},{"id":"25839","contentId":"25838"},{"id":"25838"},{"id":"25636","contentId":"25837"},{"id":"25640","contentId":"25839"}]}
function nest(data, pid) {
return data.reduce((r, e) => {
if (pid == e.contentId) {
const obj = { ...e }
const children = nest(data, e.id);
if (children.length) obj.children = children
r.push(obj)
}
return r;
}, [])
}
const result = nest(data.rec);
console.log(result[0])
I'm trying to filter this objects array and keep the original one aside.
{"departments":
[
{
“name": “AAA",
“selected”: true,
"courses": [
{
"name": “course1",
“selected”: true,
“titles”:
[{
"name": “title1",
“selected”: true
},
{
"name": “title2",
“selected”: false
}]
},
{
"name": “course2",
“selected”: false,
“titles”:
[{
"name": “title1",
“selected”: false
}]
}
]
},
{
“name": “BBB",
“selected”: false,
"courses": [{...}]
{...}
]
}
I want to find all the selected departments, courses and titles. And it should be in the same format.
I tried with below code, but it change original data. I want to keep that aside too.
const depts = departments.filter((dept: any) => {
if (dept.selected) {
dept.courses = dept.courses.filter((course: any) => {
if (course.selected) {
if (course.titles) {
course.titles = course.titles.filter(({selected}: any) => selected);
}
return true;
}
return false;
});
return true;
}
return false;
});
What would be considered the best solution in this case?
Shorter alternative can be to use the JSON.parse reviver parameter :
var arr = [{ name: "AAA", selected: true, courses: [{name: "course1", selected: true, titles: [{ name: "title1", selected: true }, { name: "title1", selected: false }]}, { name: "course2", selected: false, titles: [{ name: "title1", selected: false }]}]}]
var result = JSON.parse(JSON.stringify(arr), (k, v) => v.map ? v.filter(x => x.selected) : v)
console.log( result )
your filtering logic seems to be correct. only problem is that code changes original array. in order to overcome this problem just create a deep clone of original array and run filtering logic on it
filterArray() {
const clone = JSON.parse(JSON.stringify(this.departments));
const depts = clone.filter((dept: any) => {
if (dept.selected) {
dept.courses = dept.courses.filter((course: any) => {
if (course.selected) {
if (course.titles) {
course.titles = course.titles.filter(({ selected }: any) => selected);
}
return true;
}
return false;
});
return true;
}
return false;
});
console.log(depts);
}
here is a demo https://stackblitz.com/edit/angular-xx1kp4
const filterSelected = obj => {
return {
...obj,
departments: obj.departments.map(dep => {
return {
...dep,
courses: dep.courses.map(course => {
return {
...course,
titles: course.titles.filter(title => title.selected),
};
}).filter(course => course.selected),
};
}).filter(dep => dep.selected),
};
}
const all = {
departments: [
{
name: "AAA",
selected: true,
courses: [
{
name: "course1",
selected: true,
titles: [
{
name: "title1",
selected: true
}, {
name: "title1",
selected: false
}
]
}, {
name: "course2",
selected: false,
titles: [
{
name: "title1",
selected: false
}
]
},
]
}
]
};
console.log(filterSelected(all));
I don't know if you prefer an API false. Here is my tip:
You can to use an API Json Server.
Install JSON Server
npm install -g json-server
Create a db.json file with some data
{
"posts": [
{ "id": 1, "title": "json-server", "author": "typicode" }
],
"comments": [
{ "id": 1, "body": "some comment", "postId": 1 }
],
"profile": { "name": "typicode" }
}
Start JSON Server
json-server --watch db.json
Now if you go to http://localhost:3000/posts/1, you'll get
{ "id": 1, "title": "json-server", "author": "typicode" }
you can search your array of objects using various shapes and it will come filtered. More about the API here: https://github.com/typicode/json-server
(Use a filter to do your searches on the Angular, it will bring you right what you need, use a method inside your component)
I have a data set of the following form
let data = [
{
"id": {
"primary": "A1"
},
"msg": 1
}, {
"id": {
"primary": "A1"
},
"msg": 2
}, {
"id": {
"primary": "B2"
},
"msg": 3
}
]
I would like to transform it to
newData = [
{
"id": {
"primary": "A1"
},
"items": [
{ "msg": 1 },
{ "msg": 2 }
]
},
{
"id": {
"primary": "B2"
},
"items": [
{ "msg": 3 }
]
}
]
I think the method is something like the following, but am not sure how to check against undefined values in this case.
let newData = [];
for (let i = 0; i < data.length; i++) {
if (newData[i]['id']['primary'] === data[i]['id']) newData.push(data[i]['id'])
else newData[i]['items'].push(data[i]['msg'])
}
How can I transform the original data set to merge entries with a matching primary id?
One option would be to use .reduce() to create a new array from the existing.
I've added comments to clarify.
let data = [ { "id": { "primary": "A1" }, "msg": 1 }, { "id": { "primary": "A1" }, "msg": 2 }, { "id": { "primary": "B2" }, "msg": 3 } ];
let result = data.reduce((out,item) => {
let {id, ...items} = item; //Separate the "id" and "everything else"
let existing = out.find(({id}) => id.primary == item.id.primary);
existing //have we seen this ID already?
? existing.items.push(items) //yes - add the items to it
: out.push({ id: {...id}, items: [items]}); //no - create it
return out;
}, []);
console.log(result);
A couple notes:
You may notice that I've set the ID using id: {...id}, despite the id already being an object. This is because using the existing id object would create a reference, whereas {...id} creates a shallow copy.
I haven't specified the msg property anywhere. Instead, any properties that aren't id will be added to the items list (example below).
let data = [ { "id": { "primary": "A1" }, "msg": 1, "otherStuff": "Hello World!" }, { "id": { "primary": "A1" }, "msg": 2, "AnotherThing": true }, { "id": { "primary": "B2" }, "msg": 3, "someOtherProperty": false } ];
let result = data.reduce((out,item) => {
let {id, ...items} = item;
let existing = out.find(({id}) => id.primary == item.id.primary);
existing
? existing.items.push(items)
: out.push({ id: {...id}, items: [items]});
return out;
}, []);
console.log(result);
That said, if you start to nest objects (other than ID), they will likely be included as references; ...items is only a shallow copy.
If such a case, consider something like JSON.parse(JSON.stringify(...)) for a deep copy. Be sure to read the link though; there are caveats.
You could also solve this in a concise way via the Array.reduce and ES6 destructuring:
let data = [ { "id": { "primary": "A1" }, "msg": 1 }, { "id": { "primary": "A1" }, "msg": 2 }, { "id": { "primary": "B2" }, "msg": 3 } ]
let result = data.reduce((r, {id, msg}) =>
((r[id.primary] = r[id.primary] || { id, items: [] }).items.push({msg}), r), {})
console.log(Object.values(result))
In more readable format it is:
let data = [ { "id": { "primary": "A1" }, "msg": 1 }, { "id": { "primary": "A1" }, "msg": 2 }, { "id": { "primary": "B2" }, "msg": 3 } ]
let result = data.reduce((r, {id, msg}) => {
r[id.primary] = (r[id.primary] || { id, items: [] })
r[id.primary].items.push({msg})
return r
}, {})
console.log(Object.values(result))
The idea is to group by the id.primary and then once the grouping is done simply get the values via Object.values
Notice that this is one pass solution where you do not have to per each iteration do an Array.find against the current accumulator.
i have this array of objects : getCategory (variable)
[
{
"id": "20584",
"name": "Produits de coiffure",
"subCategory": [
{
"id": "20590",
"name": "Coloration cheveux",
"subCategory": [
{
"id": "20591",
"name": "Avec ammoniaque"
},
{
"id": "20595",
"name": "Sans ammoniaque"
},
{
"id": "20596",
"name": "Soin cheveux colorés"
},
{
"id": "20597",
"name": "Protection"
},
{
"id": "20598",
"name": "Nuancier de couleurs"
}
]
},
{
"id": "20593",
"name": "Soins cheveux",
"subCategory": [
{
"id": "20594",
"name": "Shampooing"
},
{
"id": "20599",
"name": "Après-shampooing"
},
{
"id": "20600",
"name": "Masques"
},
and i tried everything i could search in stackoverflow ..
lets say on this array i want to get recursively and object with the specified id .. like 20596 and it should return
{
"id": "20596",
"name": "Soin cheveux colorés"
}
The logic way i am doing is like this :
var getSubcategory = getCategory.filter(function f(obj){
if ('subCategory' in obj) {
return obj.id == '20596' || obj.subCategory.filter(f);
}
else {
return obj.id == '20596';
}
});
dont know what else to do .
Thanks
PS : I dont use it in browser so i cannot use any library . Just serverside with no other library . find dont work so i can only use filter
You need to return the found object.
function find(array, id) {
var result;
array.some(function (object) {
if (object.id === id) {
return result = object;
}
if (object.subCategory) {
return result = find(object.subCategory, id);
}
});
return result;
}
var data = [{ id: "20584", name: "Produits de coiffure", subCategory: [{ id: "20590", name: "Coloration cheveux", subCategory: [{ id: "20591", name: "Avec ammoniaque" }, { id: "20595", name: "Sans ammoniaque" }, { id: "20596", name: "Soin cheveux colorés" }, { id: "20597", name: "Protection" }, { id: "20598", name: "Nuancier de couleurs" }] }, { id: "20593", name: "Soins cheveux", subCategory: [{ id: "20594", name: "Shampooing" }, { id: "20599", name: "Après-shampooing" }, { id: "20600", name: "Masques" }] }] }];
console.log(find(data, '20596'));
console.log(find(data, ''));