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Conditionally disable React Checkbox

I am trying to conditionally disable the checkbox in react, based on the count. Passing the value through props whether it is checked and greater than the number. I am saving the name in the state to further process it to send to in the backend database.
Here is my react code.
class CheckboxComponent extends Component {
constructor(props) {
super(props);
this.state = {
checkedItems: {}
};
}
handleChange = (event, formKey) => {
const {checkedItems} = this.state;
const checkedValues = {...checkedItems};
checkedValues[event.target.name] = event.target.checked;
this.setState((prevState, currState) => {
return {
...prevState,
checkedItems: checkedValues
}
});
};
render = () => {
const {checkedItems} = this.state;
const checkedValues = {...checkedItems};
const checkedCount = Object.values(checkedValues).length;
const checked = Object.values(checkedValues);
const disabled = checkedCount >= 3;
return (
<div>
{checkboxes.map((item, index) => (
<label className={`form__field__input__label`} key={item.key}>
<Input
type={`checkbox`}
name={item.name}
checked={this.state.checkedItems[item.name] || false}
onChange={this.handleChange}
formKey={'subjects'}
disabled={(!checked[index] && checked.length > 3)}
/>
{item.name}
</label>
))}
</div>
)
This is the Array that I am passing to render the values in the checkbox
const checkboxes = [
{
name: "Math and economics",
key: "mathsandeconomics",
label: "Math and economics"
},
{
name: "Science",
key: "Science",
label: "Science"
},

The below code snippet will work fine for you. And you can sent object to the backend having maximum of only 3 properties set to true. Get the full code from codesandbox link https://codesandbox.io/s/emmeiwhite-0i8yh
import React from "react";
const checkboxes = [
{
name: "Math and economics",
key: "mathsandeconomics",
label: "Math and economics",
},
{
name: "Science",
key: "science",
label: "Science",
},
{
name: "history",
key: "history",
label: "history",
},
{
name: "literature",
key: "literature",
label: "literature",
},
];
class CheckboxComponent extends React.Component {
constructor(props) {
super(props);
this.state = {
checkedItems: {},
count: 0,
};
}
handleChange = (event, formKey) => {
const { name, checked } = event.target;
const updatedCheckedItems = { ...this.state.checkedItems, [name]: checked };
this.setState({
checkedItems: updatedCheckedItems,
count: Object.values(updatedCheckedItems).filter((value) => value).length,
});
};
render = () => {
const checkedValues = { ...this.state.checkedItems };
const checkedCount = Object.values(checkedValues).filter((value) => value)
.length;
console.log(this.state.checkedItems);
return (
<div>
{checkboxes.map((item, index) => (
<label className={`form__field__input__label`} key={item.key}>
<input
type={`checkbox`}
name={item.name}
checked={this.state.checkedItems[item.name] || false}
onChange={this.handleChange}
disabled={!checkedValues[item.name] && checkedCount > 2}
/>
{item.name}
</label>
))}
</div>
);
};
}
export default CheckboxComponent;

Your checked.length counts all touched boxes, not checked only. If you uncheck an input, it still will be counted. Count only true, for example Object.values(checkedValues).filter(value => value).length.
Use names instead of indexes: disabled={!checkedValues[item.name] && checkedCount > 3}
You can see full solution here: https://codesandbox.io/s/confident-http-vlm04?file=/src/App.js

event.target.getAttribute('name');
try this to get name attribute, pretty sure event.target.name is 'undefined'

I see one use case is not taken care of. checkedCount should count the number of true values only.
const checkedCount = Object.values(checkedValues).length; // existing
const checkedCount = Object.values(checkedValues).filter(item=>item==true).length //replace with this line
This would solve the problem.

Here is the code and as well as codesandbox link
Codesandbox Link
import React from "react";
export class CheckboxComponent extends React.Component {
constructor(props) {
super(props);
this.state = {
checkedItems: {},
checkedCount: 0
};
}
handleChange = (event, formKey) => {
const { checkedItems } = this.state;
const checkedValues = { ...checkedItems };
checkedValues[event.target.name] = event.target.checked;
this.setState((prevState, currState) => {
return {
...prevState,
checkedItems: checkedValues,
checkedCount: event.target.checked
? prevState.checkedCount + 1
: prevState.checkedCount - 1
};
});
};
render = () => {
const { checkboxes } = this.props;
const { checkedCount } = this.state;
const disabled = checkedCount >= 3;
return (
<div>
<p></p>
{checkboxes.map((item, index) => (
<label className={`form__field__input__label`} key={item.key}>
<input
type={`checkbox`}
name={item.name}
checked={this.state.checkedItems[item.name] || false}
onChange={this.handleChange}
disabled={!this.state.checkedItems[item.name] ? disabled : false}
/>
{item.name}
</label>
))}
</div>
);
};
}

"How to update value of item initialized from getDerivedStateFromProps on some action"?

I have initialized some const, lets say A, using getDerivedStateFromProps. Now I want to update the value on some action using setState but it's not working.
constructor(props) {
super(props)
this.state = {
A: []
}
static getDerivedStateFromProps(nextProps, prevState) {
const A = nextProps.A
return {
A
}
}
handleDragStart(e,data) {
e.dataTransfer.setData('item', data)
}
handleDragOver(e) {
e.preventDefault()
}
handleDrop(e, cat) {
const id = e.dataTransfer.getData('item')
const item = find(propEq('id', Number(id)), this.state.A)
const data = {
...item.data,
category: cat,
}
const val = {
...item,
data
}
this.setState({
A: item,
})
}
}
**Listing the items and Drag and Drop to Categorize**
{this.state.A.map((item, index) => (
<ListRow
key={`lm${index}`}
draggable
name={item.name ? item.name : ''}
description={item.data ? item.data.description : ''}
type={item.data ? item.data.target_types : ''}
source={item.data ? item.data.source : ''}
stars={item.data ? item.data.stars : []}
onDragStart={e => this.handleDragStart(e, item.id)}
onDragOver={e => this.handleDragOver(e)}
onDrop={e => this.handleDrop(e, 'process')}
onModal={() => this.handleToggleModal(item)}
/>
))}
I expect the value of A to be an item from HandleDrop but it's returning the same value that is loaded from getDerivedStateFromProps.

Here's how I solved this problem.
I used componentDidUpdate instead of getDerivedStatesFromProps.
componentDidUpdate(prevProps) {
if (!equals(this.props.A, prevPropsA)) {
const A = this.props.A
this.setState({
A
})
}
}
And the handleDrop function as
handleDrop(e, cat) {
const id = e.dataTransfer.getData('item')
const item = find(propEq('id', Number(id)), this.state.A)
const data = {
....data,
category: cat,
}
const val = {
...quota,
data
}
let {A} = this.state
const index = findIndex(propEq('id', Number(id)), A)
if (!equals(index, -1)) {
A = update(index, val, A)
}
this.setState({
A
})
}
Thank you very much for all of your help. Any suggestions or feedback for optimizing this sol will be highly appreciated. Thanks

Change Specific Property of the State

I am learning ReactJS and needless to say I am an absolute beginner! I am trying to change a specific property in the array of objects which belongs to state. Every object has two properties: name and active. active values are false by default. When I click on the item, I want to change this item's active value to true.
My array is shown inside of the list element and every list element has onClick={() => props.onChangeSelected(lang.name)} method. onChangeSleceted method goes to handleChangeSelected(name) function, however, I couldn't figure out what to write inside of this function.
class Loading extends React.Component {
constructor(props) {
super(props);
this.state = {
text: 'Loading'
};
}
componentDidMount() {
const stopper = this.state.text + '...';
this.interval = window.setInterval(() => {
this.state.text === stopper
? this.setState(() => ({ text: 'Loading' }))
: this.setState((prevState) => ({ text: prevState.text + '.' }))
}, 300)
}
componentWillUnmount() {
window.clearInterval(this.interval);
}
render() {
return (
<p>
{this.state.text}
</p>
)
}
}
function LanguageList (props) {
return (
<div>
<h3>Choose your favorite:</h3>
<ul>
{props.list.map((lang) => (
<li key={lang.name} onClick={() => props.onChangeSelected(lang.name)}>
<span>{lang.name}</span>
</li>
))}
</ul>
</div>
)
}
class App extends React.Component {
constructor(props) {
super(props)
this.state = {
languages: [
{
name: 'all',
active: true
},
{
name: 'javascript',
active: false
},
{
name: 'ruby',
active: false
},
{
name: 'python',
active: false
}
]
}
this.handleChangeSelected = this.handleChangeSelected.bind(this)
}
handleChangeSelected(name) {
this.setState((currentState) => {
const lang = currentState.languages.find((lang) => lang.name === name)
return {}
})
}
render() {
return (
<div>
<LanguageList
list={this.state.languages}
onChangeSelected={this.handleChangeSelected}
/>
</div>
)
}
}
ReactDOM.render(
<App />,
document.getElementById('app')
)
</script>

You can do it in a number of ways. All you need to make sure is that you aren't mutating the original state array
handleChangeSelected(name) {
this.setState((currentState) => {
return { languages: currentState.languages.map((lang) => {
if(lang.name === name) {
return {...lang, active: true};
}
return lang;
});
})
}

Try this?
handleChangeSelected(name){
// Find matching element in state
var temp = this.state.languages;
for (var i = 0; i < temp.length; i++){
if (temp[i]["name"] === name){
temp[i]["active"] = true;
}
}
this.setState({
languages: temp
});
}
As listed in the React docs, they recommend creating a new object when calling the setState function. This is of course talking about the updater function syntax (this.setState((prevState, props) => {return {...};});), which I assume the same logic is applied to the syntax used above (passing an object into set state)
The first argument [to setState] is an updater function with the signature:
(prevState, props) => stateChange
(prevState, props) => stateChange prevState is a reference to the
previous state. It should not be directly mutated. Instead, changes
should be represented by building a new object based on the input from
prevState and props.

react js delete handler removes the 1st index in the array

The problem is any item button click will delete the 1st index item in the array.
I looked at these resources on handling deleting an item in an array in react.
How to remove item in todo list using React
Removing element from array in component state
React Binding Patterns
I've tried changing how my handler is called in TodoList and TodoItemLIst and that causes the handler not to fire on click. I've tried different methods of binding the handler - adding a param has no effect on it -bind(this) breaks it & isn't necessary because I'm using a function.
I've tried setting state different ways using a filter method. No change happens...
this.setState((prevState) => ({
todoItems: prevState.todoItems.filter(i => i !== index)
}));
I'm not understanding where/what the problem is.
class App extends Component {
constructor(props) {
super(props);
this.state = {
value: '',
listItemValue: props.value || '',
todoItems: [
{id: _.uniqueId(), item: 'Learn React.'},
{id: _.uniqueId(), item: 'Improve JS skills.'},
{id: _.uniqueId(), item: 'Play with kittens.'}
]
};
}
handleChange = (event) => {
let value = event.target.value;
this.setState({
value: this.state.value,
listItemValue: value
});
}
handleSubmit = (event) =>{
event.preventDefault();
this.setState({
value: '',
listItemValue: ''
});
}
addTodoItem = () => {
let todoItems = this.state.todoItems.slice(0);
todoItems.push({
id: _.uniqueId(),
item: this.state.listItemValue
});
this.setState(prevState => ({
todoItems: [
...prevState.todoItems,
{
id: _.uniqueId(),
item: this.state.listItemValue
}]
}))
};
deleteTodoItem = (index) => {
let todoItems = this.state.todoItems.slice();
todoItems.splice(index, 1);
this.setState({
todoItems
});
}
render() {
return (
<div className="App">
<h1>Todo List</h1>
<TodoListForm name="todo"
onClick={ ()=>this.addTodoItem() }
onSubmit={ this.handleSubmit }
handleChange={ this.handleChange }
value={ this.state.listItemValue } />
<TodoList onClick={ ()=>this.deleteTodoItem() }
todoItems={ this.state.todoItems }/>
</div>
);
}
}
const TodoList = (props) => {
const todoItem = props.todoItems.map((todo) => {
return (
<TodoListItem onClick={ props.onClick }
key={ todo.id }
id={ todo.id }
item={ todo.item }/>
);
});
return (
<ul className="TodoList">
{todoItem}
</ul>
);
}
const TodoListItem = (todo, props) => {
return (
<li className="TodoListItem">
<div className="TodoListItem__Item">{todo.item}
<span className="TodoListItem__Icon"></span>
<button onClick={ todo.onClick }
type="button"
className="TodoListItem__Btn">×</button>
</div>
</li>
)
};

In the deleteTodoItem method, try just
let todoItems = this.state.todoItems.slice(0, -1);
and remove the call to splice().

Arrays - Javascript - filter array of objects using input search

I am trying to filter a list using react, but surprisingly, for such a common task, cannot find anything online to help me achieve this.
I have an array of users which I then want to filter through (starting off with name - I can work out filtering by age then).
The array is in my redux store and looks like the below.
let users = [
{
name: 'Raul',
age: 29
},
{
name: 'Mario',
age: 22
}
];
My entire component looks like the below.
class Test extends Component {
constructor(props) {
super(props);
this.state = {
users: this.props.users
};
this.filterList = this.filterList.bind(this);
}
componentWillReceiveProps(nextProps) {
this.setState({
users: nextProps.users
});
}
filterList(event) {
let users = this.state.users;
users = users.filter(function(user){
//unsure what to do here
});
this.setState({users: users});
}
render(){
const userList = this.state.users.map((user) => {
return <li>{user.name} {user.age}</li>;
});
return(
<input type="text" placeholder="Search" onChange={this.filterList}/>
<ul>
{ userList }
</ul>
);
}
}

If you want to filter for name you can use .filter together with .startsWith or .indexOf to return true or false for a given user.
You've also set a new list of users on the onChange event, which results in an empty array sooner or later. Here I've used the user state that is only changed by the props, and a filteredUsers that is changed when a keystroke happened.
class Test extends React.Component {
constructor(props) {
super(props);
this.state = {
users: this.props.users,
filteredUsers: this.props.users,
q: ''
};
this.filterList = this.filterList.bind(this);
this.onChange = this.onChange.bind(this);
}
componentWillReceiveProps(nextProps) {
this.setState(
{
users: nextProps.users,
filteredUsers: nextProps.users
},
() => this.filterList()
);
}
onChange(event) {
const q = event.target.value.toLowerCase();
this.setState({ q }, () => this.filterList());
}
filterList() {
let users = this.state.users;
let q = this.state.q;
users = users.filter(function(user) {
return user.name.toLowerCase().indexOf(q) != -1; // returns true or false
});
this.setState({ filteredUsers: users });
}
render() {
const userList = this.state.filteredUsers.map(user => {
return <li>{user.name} {user.age}</li>;
});
return (
<div>
<input
type="text"
placeholder="Search"
value={this.state.q}
onChange={this.onChange}
/>
<ul>
{userList}
</ul>
</div>
);
}
}
const userList = [
{
name: 'Raul',
age: 29
},
{
name: 'Mario',
age: 22
}
];
ReactDOM.render(<Test users={userList} />, document.getElementById('root'));
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>
<div id="root"></div>

You need one more state variable to store the search result, initialise that variable by same data, once user type anything store the filtered data in that, Try this:
let users = [
{
name: 'Raul',
age: 29
},
{
name: 'Mario',
age: 22
}
];
class Test extends React.Component {
constructor(props) {
super(props);
this.state = {
users: users,
result: users,
};
this.filterList = this.filterList.bind(this);
}
componentWillReceiveProps(nextProps) {
this.setState({
users: nextProps.users,
});
}
filterList(event) {
let value = event.target.value;
let users = this.state.users, result=[];
result = users.filter((user)=>{
return user.name.toLowerCase().search(value) != -1;
});
this.setState({result});
}
render(){
const userList = this.state.result.map((user) => {
return <li>{user.name} {user.age}</li>;
});
return(<div>
<input type="text" placeholder="Search" onChange={this.filterList}/>
<ul>
{userList}
</ul>
</div>
);
}
}
ReactDOM.render(<Test/>, document.getElementById('app'))
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>
<div id='app'></div>

let datas =[
{
"id":1,
"title":"Ucat",
"handle":"mi"
},
{
"id":2,
"title":"Acat",
"handle":"csk"
},
{
"id":3,
"title":"Vcat",
"handle":"kkr"
},
{
"id":4,
"title":"Atar",
"handle":"pkbs"
}];
const [search, setSearch] =useState(datas);
const handleInputChange = (e) => {
var dm = e.target.value;
var str =dm.toString();
var debug = datas.filter(x=> x["title"].toLowerCase().includes(str));
setSearch(debug);};
<input type="text" onChange={handleInputChange}/>
{search.map((item)=>(
<div key={item.id}>
<ul>
<li>
{item.handle}
<br/>
{item.title}
</li>
</ul>
</div>
))};

If you want to filter the list, you must have a criteria to filter against. For instance you have a variable let filterAge = 18;
In that case you can filter the userlist against that value using
let users = users.filter(function(user){
//return all users older or equal to filterAge
return user.age >= filterAge;
});
Every result from the function that equals true, will be added to the users variable. A false return will leave it out. How you determine true / false is up to you. Hardcode it (not very useful), a simple equals statement (as above) or a function doing higher math. Your choice.

It always worked well for me that way.
const [data, setData] = useState([{name: 'Kondo'}, {name: 'Gintoki'}])
const handleFilterFilesTable = () => {
return data
.filter((element) => {
if (searchText !== "") {
return element?.name?.toLowerCase()?.includes(searchText?.toLowerCase())
}
return element
})
}
// ...
return (
//...
<Table data={handleFilterFilesTable()} />
)
That way I can apply multiple filters working together simply by extending the filter method like this
// ...
return data.filter().filter().filter()//...
// ...