How to toggle dynamically generated dropdowns using the .map functions index? - reactjs

Question

I have a array that for every item in the array a drop down list is dynamically generated. Right now each drop down list share the same toggle boolean so they all open and close and the same time, how can I make this work individually?
I map each object to a index here and then start creating dropdowns:
{Object.keys(props.totalWorkload.options).map((item, i) => (
<WorkloadOptions
key={i}
cnt={i}
appendChoiceList={props.appendChoiceList}
modalDropDown={props.modalDropDown}
toggleDropDown={props.toggleDropDown}
totalWorkloadOptions={props.totalWorkload.options[item]}
/>
))}
When the Drop Down options component is created I pass the index to a function:
<div>
<Dropdown isOpen={props.modalDropDown} toggle={props.toggleDropDown.bind(props.cnt)}>
<DropdownToggle caret>{props.totalWorkloadOptions.optionTitle}</DropdownToggle>
<DropdownMenu>
{props.totalWorkloadOptions.options.map(op => (
// tslint:disable-next-line:no-invalid-this
// tslint:disable-next-line:jsx-no-lambda
<DropdownItem key={op} onClick= {() => props.appendChoiceList(props.totalWorkloadOptions.optionTitle, op)}>
{op}
</DropdownItem>
))}
</DropdownMenu>
<strong> {props.totalWorkloadOptions.optionDescription} </strong>
</Dropdown>
<br />
</div>
The it will arrrive at the following functuion and console log the index and then set the appropriate toggle value in an array to true/false:
toggleDropDown = (index: any) => {
console.log('triggered!:' + index);
let clicked = this.state.modalDropDownClicked;
// tslint:disable-next-line:no-conditional-assignment
if (clicked[index]=!clicked[index]){
this.setState({ modalDropDownClicked: !this.state.modalDropDown[index] });
}
};

Answer 1

I can recommend the following pattern to toggle dynamically created elements:
// Item.js
class Item extends React.Component {
handleClick = () => {
const { id, onClick } = this.props;
onClick(id);
}
render() {
const { isOpen } = this.props;
return (
<li><button onClick={this.handleClick}>{isOpen ? 'open' : 'closed'}</button></li>
)
}
}
// App.js
class App extends React.Component {
static getDerivedStateFromProps(nextProps, prevState) {
const { items } = nextProps;
if (items !== prevState.prevPropsItems) {
return { items, prevPropsItems: items };
}
return null;
}
state = {
prevPropsItems: [],
items: []
}
toggleItem = id => this.setState(prevState => {
const items = prevState.items.map(item => {
if (item.id === id) {
return { ...item, isOpen: !item.isOpen }
} else {
return item;
}
});
return { items }
})
render(){
const { items } = this.state;
return (<ul>
{items.map(item => <Item key={item.id} id={item.id} onClick={this.toggleItem} isOpen={item.isOpen} />)}
</ul>);
}
}
// AppContainer.js
const itemsFromRedux = [
{ id: '1', isOpen: false },
{ id: '2', isOpen: false },
{ id: '3', isOpen: false },
]
ReactDOM.render(<App items={itemsFromRedux} />, document.getElementById('root'))
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.6.1/umd/react.development.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.6.1/umd/react-dom.development.js"></script>
<div id="root"></div>