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30-seconds-of-code/snippets/MultiselectCheckbox.md
Angelos Chalaris 2a28e1dff1 Resolve #53
2019-03-06 20:46:04 +02:00

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### MultiselectCheckbox
Renders a checkbox list that uses a callback function to pass its selected value/values to the parent component.
* Use `React.setState()` to create a `data` state variable and set its initial value equal to the `options` prop.
* Create a function `toggle` that is used to toggle the `checked` to update the `data` state variable and call the `onChange` callbac passed via the component's props.
* Render a `<ul>` element and use `Array.prototype.map()` to map the `data` state variable to individual `<li>` elements with `<input>` elements as their children.
* Each `<input>` element has the `type='checkbox'` attribute and is marked as `readOnly`, as its click events are handled by the parent `<li>` element's `onClick` handler.
```jsx
const style = {
listContainer: {
listStyle: 'none',
paddingLeft: 0
},
itemStyle: {
cursor: 'pointer',
padding: 5
}
};
function MultiselectCheckbox({ options, onChange }) {
const [data, setData] = React.useState(options);
const toggle = item => {
data.map((_, key) => {
if (data[key].label === item.label) data[key].checked = !item.checked;
});
setData([...data]);
onChange(data);
};
return (
<ul style={style.listContainer}>
{data.map(item => {
return (
<li key={item.label} style={style.itemStyle} onClick={() => toggle(item)}>
<input readOnly type="checkbox" checked={item.checked || false} />
{item.label}
</li>
);
})}
</ul>
);
}
```
```jsx
const options = [{ label: 'Item One' }, { label: 'Item Two' }];
ReactDOM.render(
<MultiselectCheckbox
options={options}
onChange={data => {
console.log(data);
}}
/>,
document.getElementById('root')
);
```
<!-- tags: input,state,array -->
<!-- expertise: 1 -->