如何限制草稿js的最大长度 [英] How to limit Max Length of Draft js
本文介绍了如何限制草稿js的最大长度的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
如何限制js草稿中的最大字符数?
How to limit max characters in draft js?
我可以得到类似状态的长度,但是如何停止更新组件?
I can get length of the state like that, but how to stop updating component?
var length = editorState.getCurrentContent().getPlainText('').length;
推荐答案
您应定义 handleBeforeInput
和 handlePastedText
道具.在处理程序功能中,您检查当前内容的长度+粘贴文本的长度,如果达到最大值,则应返回'handled'
字符串.
UPD 21.03.2018:已升级到最新版本的react/react-dom(16.2.0)和Draft.js(0.10.5).
工作示例- https://jsfiddle.net/Ln1hads9/11/
const {Editor, EditorState} = Draft;
const MAX_LENGTH = 10;
class Container extends React.Component {
constructor(props) {
super(props);
this.state = {
editorState: EditorState.createEmpty()
};
}
render() {
return (
<div className="container-root">
<Editor
placeholder="Type away :)"
editorState={this.state.editorState}
handleBeforeInput={this._handleBeforeInput}
handlePastedText={this._handlePastedText}
onChange={this._handleChange}
/>
</div>
);
}
_getLengthOfSelectedText = () => {
const currentSelection = this.state.editorState.getSelection();
const isCollapsed = currentSelection.isCollapsed();
let length = 0;
if (!isCollapsed) {
const currentContent = this.state.editorState.getCurrentContent();
const startKey = currentSelection.getStartKey();
const endKey = currentSelection.getEndKey();
const startBlock = currentContent.getBlockForKey(startKey);
const isStartAndEndBlockAreTheSame = startKey === endKey;
const startBlockTextLength = startBlock.getLength();
const startSelectedTextLength = startBlockTextLength - currentSelection.getStartOffset();
const endSelectedTextLength = currentSelection.getEndOffset();
const keyAfterEnd = currentContent.getKeyAfter(endKey);
console.log(currentSelection)
if (isStartAndEndBlockAreTheSame) {
length += currentSelection.getEndOffset() - currentSelection.getStartOffset();
} else {
let currentKey = startKey;
while (currentKey && currentKey !== keyAfterEnd) {
if (currentKey === startKey) {
length += startSelectedTextLength + 1;
} else if (currentKey === endKey) {
length += endSelectedTextLength;
} else {
length += currentContent.getBlockForKey(currentKey).getLength() + 1;
}
currentKey = currentContent.getKeyAfter(currentKey);
};
}
}
return length;
}
_handleBeforeInput = () => {
const currentContent = this.state.editorState.getCurrentContent();
const currentContentLength = currentContent.getPlainText('').length;
const selectedTextLength = this._getLengthOfSelectedText();
if (currentContentLength - selectedTextLength > MAX_LENGTH - 1) {
console.log('you can type max ten characters');
return 'handled';
}
}
_handlePastedText = (pastedText) => {
const currentContent = this.state.editorState.getCurrentContent();
const currentContentLength = currentContent.getPlainText('').length;
const selectedTextLength = this._getLengthOfSelectedText();
if (currentContentLength + pastedText.length - selectedTextLength > MAX_LENGTH) {
console.log('you can type max ten characters');
return 'handled';
}
}
_handleChange = (editorState) => {
this.setState({ editorState });
}
}
ReactDOM.render(<Container />, document.getElementById('react-root'))
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