How to update nested array of objects in ReactJS - reactjs

I have an array of object like this:
const tempobj = [
{
id: "1",
fanimate: [
{
id: "111",
animate: "xyz",
},
],
},];
Now I want to add more animations inside this array, such that each object gets added in the fanimate such that:
const tempobj = [
{
id: "1",
fanimate: [
{
id: "111",
animate: "xyz",
},
{
id: "222",
animate: "def",
},
],
},];
I tried using the hook useState, but I am getting undefined results

const tempobj = [
{
id: "1",
fanimate: [
{
id: "111",
animate: "xyz",
},
],
}];
const modified = tempobj.map(temp => {
const newtemp = {
id: temp.id,
fanimate: [...temp.fanimate, {id:"222", animate:"def"}]
}
return newtemp;
})
console.log(modified);

You could just spread all the places
const tempObj = {
id:'1',
fan:[
{
id:'2',
animate:'xyz'
}
]
}
console.log(tempObj)
const newtest={...testObj,fan:[...testObj.fan, {id:'3', animate:'tuz'}]}
console.log(newtest)

Try this:
const tempobj = [
{
id: "1",
fanimate: [
{
id: "111",
animate: "xyz"
}
]
}
];
const [state, setState] = useState(tempobj);
function updateArray(newItem) {
setState(
state.map((item) => ({ ...item, fanimate: [...item.fanimate, newItem] }))
);
}
You can push the newItem to the original fanimate array using spread operator, everytime a new item is added, the original array data is copied by ...item.fanimate:
{ ...item, fanimate: [...item.fanimate, newItem] }
BTW the naming of tempobj really should be tempArr or tempArray.
A working sandbox

Related

How to delete new array in react native object

I have following array
[{
"games1": [{
"playername": "1"
}]
},
{
"games2": [{
"playername": "1"
},
{
"playername": "2"
}
]
}
]
I want to delete games2 from the array how to do this
I want this type of output
[{
"games1": [{
"playername": "1"
}]
}
}]
Use filter to filter what you want to keep.
Like this:
const arr = [
{
games1: [
{
playername: '1',
},
],
},
{
games2: [
{
playername: '1',
},
{
playername: '2',
},
],
},
]
// keep games1
const newArr = arr.filter((r) => r.games1)
console.log(newArr)
// remove games2, keep others
const newArr2 = arr.filter((r) => !r.games2)
console.log(newArr2)
output would be
[
{
"games1": [
{
"playername": "1"
}
]
}
]
const NewArray = array.filter((item) => item !== "games2");
console.log(NewArray)
Try the below code:
let final = x.filter(x=>{
let c = Object.getOwnPropertyNames(x)
return c!="games2"
})
here the output of the 'final' is :
[{
"games1": [{
"playername": "1"
}]
}
}]

how i can add an object to a nested array in reducer?

const initState = {
questions:[
{
id: uuidv4(),
answers:[
{answerid: uuidv4()},
{answerid: uuidv4()}
]
},
],
}
this is the state i wanna function to add object in the answers array so the state will be after add like that:
const initState = {
questions:[
{
id: uuidv4(),
answers:[
{answerid: uuidv4()},
{answerid: uuidv4()},
{answerid: uuidv4()}
]
},
],
}
you can use a library like Immer for deeply nested objects update,
My try as below
const initState = {
questions: [
{
id: 1,
answers: [
{
answerid: 34,
},
{
answerid: 12,
},
],
},
],
};
const newState = {
...initState,
questions: initState.questions.map((q) => {
const newq = {
...q,
answers: [
...q.answers,
{
a: "b",
},
],
};
return newq;
}),
};
newState.questions[0].id = 2; // to test it doesn't mutate original object
console.log({initState, newState});

Convert array of Objects into a grouped array of Objects Typescript

I'm trying to convert an array of objects like this:
[{grandParentField:'grandParent1', parentField:'parent1', childField: 'child1'},
{grandParentField:'grandParent1', parentField:'parent1', childField: 'child2'},
{grandParentField:'grandParent2', parentField:'parent1', childField: 'child3'},
{grandParentField:'grandParent2', parentField:'parent2', childField: 'child4'}]
into this form:
[
{
text: 'grandparent1',
items: [
{
text: 'parent1',
items: [{ text: 'child1' }, { text: 'child2' }]
}
]
},
{
text: 'grandparent2',
items: [
{
text: 'parent1',
items: [{ text: 'child3' }]
},
{
text: 'parent2',
items: [{ text: 'child4' }]
}
]
}
]
This Thread is similar to what I want, but not quite.
children will always be unique, but parents can have multiple grandparents.
Honestly I've tried so many things I'm not even sure which one to include as an example of what has gotten me closest.
Something like this but able to take in an array of Objects, and pump out the {text: string, items:[{text: string, items:[{text:string]]} structure:
var groupBy = function(xs, key) {
return xs.reduce(function(rv, x) {
(rv[x[key]] = rv[x[key]] || []).push(x);
return rv;
}, {});
};
console.log(groupBy(['one', 'two', 'three'], 'length'));
// => {3: ["one", "two"], 5: ["three"]}
Recursive approach, should work for every n-nested input that you will provide:
const input =[{grandParentField:"grandParent1",parentField:"parent1",childField:"child1"},{grandParentField:"grandParent1",parentField:"parent1",childField:"child2"},{grandParentField:"grandParent2",parentField:"parent1",childField:"child3"},{grandParentField:"grandParent2",parentField:"parent2",childField:"child4"}];
const nestedGroupBy = (nodes, order, orderIdx = 0) => {
const key = order[orderIdx]
let grouped = nodes.reduce((acc, e, i) => {
let node = acc.find(x => x.text == e[key])
if (!node) {
node = { text: e[key], items: [] }
acc.push(node)
}
node.items ? node.items.push(e) : node.items = [e]
return acc
}, [])
if (order[orderIdx + 1])
grouped = grouped.map(e => ({
text: e.text,
items: nestedGroupBy(e.items, order, orderIdx + 1)
}))
else
grouped = grouped.map(e => ({ text: e.text }) )
return grouped
}
const res = nestedGroupBy(input, Object.keys(input[0]))
console.log(res)
.as-console-wrapper { max-height: 100% !important; top: 0; }
Without getting too crazy with types, I'd say that you want your output to be of this shape:
interface Tree {
text: string,
items?: Tree[]
}
So let's make a function called group() which takes your array and a list of keys that you want to process in the order they should be processed. So for your example it would be used like this:
const data = [
{ grandParentField: 'grandParent1', parentField: 'parent1', childField: 'child1' },
{ grandParentField: 'grandParent1', parentField: 'parent1', childField: 'child2' },
{ grandParentField: 'grandParent2', parentField: 'parent1', childField: 'child3' },
{ grandParentField: 'grandParent2', parentField: 'parent2', childField: 'child4' }
];
const groupedData = group(data, "grandParentField", "parentField", "childField");
Here's the implementation of group():
function group(data: Array<Record<string, string>>, key: string, ...otherKeys: string[]): Tree[] {
const objMap: Record<string, any[]> = {}
for (const d of data) {
if (!(d[key] in objMap)) {
objMap[d[key]] = []
}
objMap[d[key]].push(d);
}
return Object.keys(objMap).map(k => otherKeys.length ?
{
text: k,
items: group(objMap[k], otherKeys[0], ...otherKeys.slice(1))
} : {
text: k
}
);
}
First we group the elements from data into a dictionary of arrays called objMap, where each element d goes into the key of objMap at d[key] (so the first element goes into the key named "grandParent1" if key is "grandParentField").
Once this grouping is done, we return a new array by walking through objMap's keys. If we have no otherKeys, we just return an array of {text: string} elements using the keys of objMap as the text field. If we do have other keys, then we need to recursively call group() on the elements stored in objMap at the proper key.
You can verify that this works for your example:
console.log(JSON.stringify(groupedData, undefined, 2));
/* [
{
"text": "grandParent1",
"items": [
{
"text": "parent1",
"items": [
{
"text": "child1"
},
{
"text": "child2"
}
]
}
]
},
{
"text": "grandParent2",
"items": [
{
"text": "parent1",
"items": [
{
"text": "child3"
}
]
},
{
"text": "parent2",
"items": [
{
"text": "child4"
}
]
}
]
}
] */
Playground link to code

How to add the array to useState correctly?

I define a state like this:
const [user, setUser] = useState(
[] as { userId: string; userHabbitList: string[] }[],
)
My API will be like this:
userList = [
{
"id": "1",
"userHabbit": [
{
"userHabbitId": "1"
},
{
"userHabbitId": "2"
}
]
},
{
"id": "2",
"userHabbit": [
{
"userHabbitId": "3"
},
{
"userHabbitId": "4"
}
]
}
]
Here is my working:
setUser(
userList.map( e =>
({
userId: e.id,
userHabbitList: e.userHabbit.map( u => u.userHabbitId)
})
)
)
However the userHabbitList still empty,
Here is my expect result:
[
{userId: "1", userHabbitList: ["1","2"]},
{userId: "2", userHabbitList: ["3","4"]}
]

How to create nested array in realm without key(React Native)

{
"a": [
[
{
"_id": "57e55b64016c3551c025abc1",
"title": "Main Campus"
},
{
"_id": "5810e2e27064497f74ad4874",
"title": "Ahm Campus"
},
{
"_id": "5d5d2633a1d0680620ac3cce",
"title": "Baroda"
},
{
"_id": "5d5d3af3a1d0680620ac3ef8",
"title": "India"
}
],
[
{
"_id": "57e55b64016c3551c025abc1",
"title": "Main Campus"
},
{
"_id": "5810e2e27064497f74ad4874",
"title": "Ahm Campus"
},
{
"_id": "5d5d2633a1d0680620ac3cce",
"title": "Baroda"
},
{
"_id": "5d5d3af3a1d0680620ac3ef8",
"title": "India"
}
]
]
}
How to create the schema in the realm(React native) for this type of JSON object. I tried all possible ways but did not found any specific solution. Basically, it is a nested array where the second array does not have any specific key(I tried with key it works fine but I want to do it without adding key).
You can use something like:
const ParentSchema = {
name: "parent",
properties: {
key: "string",
values: "Value[]"
}
};
const ValueSchema = {
name: "Value",
embedded: true,
properties: {
_id: "string",
title: "string"
}
};
You can insert objects like:
realm.write(() => {
realm.create("Parent", { key: "a", values: [
{ _id: "57e55b64016c3551c025abc1", title: "Main Campus" },
{ _id: "5810e2e27064497f74ad4874", title: "Ahm Campus" }
]
});
});
Documentation: https://docs.mongodb.com/realm/node/data-model
As of now there is no way to insert direct value in Realm database without key so for now we need to modify data and then we can store in following schema.
const ParentSchema = {
name: "parent",
properties: {
a: "level[]"
}
};
const level = {
name: 'level',
properties: {
level: 'sites[]'
}
}
const sites = {
name: 'sites',
properties: {
sites: 'site[]'
}
}
const site = {
name: 'site',
properties: {
title: 'string?',
_id: 'string?',
version: 'int?',
}
}
Data modification need to done like following.
var a = {
level: []
}
data.a.map((Site, index) => {
const sites = []
Site.map((s) => { sites.push(s)})
a.level.push({sites})
})

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