Merge pull request #30 from 30-seconds/limited-word-textarea

add limited word text area
This commit is contained in:
Angelos Chalaris
2019-02-20 18:27:20 +02:00
committed by GitHub

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### LimitedWordTextarea
Renders a textarea component with a word limit.
Use the `React.useState()` hook to create the `content` and `wordCount` state variables and set their values to `value` and `0` respectively.
Create a method `setFormattedContent`, which uses `String.prototype.split(' ')` to turn the input into an array of words and check if the result of applying `Array.prototype.filter(Boolean)` has a `length` longer than `limit`.
If the afforementioned `length` exceeds the `limit`, trim the input, otherwise return the raw input, updating `content` and `wordCount` accordingly in both cases.
Use the `React.useEffect()` hook to call the `setFormattedContent` method on the value of the `content` state variable.
Use a`<div>` to wrap both the`<textarea>` and the `<p>` element that displays the character count and bind the `onChange` event of the `<textarea>` to call `setFormattedContent` with the value of `event.target.value`.
```jsx
function LimitedWordTextarea({ rows, cols, value, limit }) {
const [content, setContent] = React.useState(value);
const [wordCount, setWordCount] = React.useState(0);
const setFormattedContent = text => {
let words = text.split(" ");
if (words.filter(Boolean).length > limit) {
setContent(
text
.split(" ")
.slice(0, limit)
.join(" ")
);
setWordCount(limit);
} else {
setContent(text);
setWordCount(words.filter(Boolean).length);
}
};
React.useEffect(() => {
setFormattedContent(content);
}, []);
return (
<div>
<textarea
rows={rows}
cols={cols}
onChange={event => setFormattedContent(event.target.value)}
value={content}
/>
<p>
{wordCount}/{limit}
</p>
</div>
);
}
```
```jsx
ReactDOM.render(
<LimitedWordTextArea limit={5} value='Hello there!' />,
document.getElementById('root')
);
```
<!-- tags: input,state,effect -->
<!-- expertise: 0 -->