回应:编辑contentEditable div时如何保持插入符号位置?

时间:2019-04-27 14:09:53

标签: javascript html reactjs

当前

  1. 我有一个react组件,当用户单击contentEditable newValue时存储一个<div>,并在用户键入时更新newValue注意:之所以以这种方式设置此行为,主要有两个原因:(1)我不想发送要在每次击键时保存的数据,并且(2)我计划使用以下形式此div,将检查每个输入以验证输入是否为数字。
  2. newValue失去焦点后,<div>被发送以保存,然后重置道具的状态。

问题

onChangeHandler正在将插入标记在可编辑div中的位置移到左侧。这导致按键123456显示为654321

代码:

class Input extends Component {

  constructor(props) {
    super(props);
    this.state = {
      //newValue input by user
      newValue : undefined
    }
  }

  //handler during key press / input
  onChangeHandler = event => {
    let targetValue =  event.currentTarget.textContent;
    this.setState({"newValue": targetValue})
  }

  //handler when user opens input form
  onBlurHandler = event => {
    //some code that sends the "newValue" to be saved, and resets state
  }

  render() {
    //determine which value to show in the div
    let showValue;
    //if there is a new value being input by user, show this value
    if (this.state.newValue !== undefined) {
      showValue = this.state.newValue;
    } else {
      //if prop has no value e.g. null or undefined, use "" placeholder
      if (this.props.value) {
        showValue = this.props.value;
      } else {
        showValue = "";
      }
    }

    return (
    <table>
    <tbody>
      <td>
          <div
            contentEditable="true"
            suppressContentEditableWarning="true"
            onInput={this.onChangeHandler.bind(this)}
            onBlur={this.onBlurHandler}
          >{showValue}
          </div>
      </td>
     </tbody>
     </table>
    )
  }
}

export default Input;

注释

  1. 我以前是使用<textarea>来完成此操作的,但没有这个问题,但是切换到<div>可以更好地控制自动调整div高度的行为(参考CSS: Remove scroll bar and replace with variable height for textarea in a table <td>)< / li>
  2. 我已经找到了许多相关的答案,但是没有一个特定的答案,例如Maintain cursor position in contenteditable div。我认为是因为React在每个笔划后都会重新加载组件,所以会出现此问题。
  3. 我以前没有Input上的ChangeHandler,并且运行良好,但是我无法记录每个按键并验证字符是否为数字。

3 个答案:

答案 0 :(得分:1)

ContentEditable是一个棘手的问题,特别是在做出反应时,因为您必须考虑许多不同种类的行为。我可以建议您看看Facebook的DraftJS。

他们采用contentEditable并阻止了所有默认行为,并建立了一个不错的框架来使标签可编辑,他们将其用于富文本编辑器,但是您可以使用相同的框架而不必费吹灰之力就可以控制内容可编辑的。

https://draftjs.org/docs/getting-started

答案 1 :(得分:0)

我能够在https://stackoverflow.com/a/13950376/1730260

中获得以下解决方案

主要更改:

  1. 添加具有两个功能的新组件EditCaretPositioning.js:(1)saveSelection保存插入符位置,(2)restoreSelection恢复插入符位置。
  2. 将插入符号位置保存为Input组件状态
  3. 每次 Change 事件后呼叫saveSelection()
  4. 设置状态后,
  5. restoreSelection()作为回调
  6. id中添加了<div>,因此可以在restoreSelection()函数中引用

EditCaretPositioning.js

const EditCaretPositioning = {}

export default EditCaretPositioning;


if (window.getSelection && document.createRange) {
    //saves caret position(s)
    EditCaretPositioning.saveSelection = function(containerEl) {
        var range = window.getSelection().getRangeAt(0);
        var preSelectionRange = range.cloneRange();
        preSelectionRange.selectNodeContents(containerEl);
        preSelectionRange.setEnd(range.startContainer, range.startOffset);
        var start = preSelectionRange.toString().length;

        return {
            start: start,
            end: start + range.toString().length
        }
    };
    //restores caret position(s)
    EditCaretPositioning.restoreSelection = function(containerEl, savedSel) {
        var charIndex = 0, range = document.createRange();
        range.setStart(containerEl, 0);
        range.collapse(true);
        var nodeStack = [containerEl], node, foundStart = false, stop = false;

        while (!stop && (node = nodeStack.pop())) {
            if (node.nodeType === 3) {
                var nextCharIndex = charIndex + node.length;
                if (!foundStart && savedSel.start >= charIndex && savedSel.start <= nextCharIndex) {
                    range.setStart(node, savedSel.start - charIndex);
                    foundStart = true;
                }
                if (foundStart && savedSel.end >= charIndex && savedSel.end <= nextCharIndex) {
                    range.setEnd(node, savedSel.end - charIndex);
                    stop = true;
                }
                charIndex = nextCharIndex;
            } else {
                var i = node.childNodes.length;
                while (i--) {
                    nodeStack.push(node.childNodes[i]);
                }
            }
        }

        var sel = window.getSelection();
        sel.removeAllRanges();
        sel.addRange(range);
    }



} else if (document.selection && document.body.createTextRange) {
  //saves caret position(s)
    EditCaretPositioning.saveSelection = function(containerEl) {
        var selectedTextRange = document.selection.createRange();
        var preSelectionTextRange = document.body.createTextRange();
        preSelectionTextRange.moveToElementText(containerEl);
        preSelectionTextRange.setEndPoint("EndToStart", selectedTextRange);
        var start = preSelectionTextRange.text.length;

        return {
            start: start,
            end: start + selectedTextRange.text.length
        }
    };
    //restores caret position(s)
    EditCaretPositioning.restoreSelection = function(containerEl, savedSel) {
        var textRange = document.body.createTextRange();
        textRange.moveToElementText(containerEl);
        textRange.collapse(true);
        textRange.moveEnd("character", savedSel.end);
        textRange.moveStart("character", savedSel.start);
        textRange.select();
    };

}

更新后的contentEditable div组件:

import CaretPositioning from 'EditCaretPositioning'

class Input extends Component {

  constructor(props) {
    super(props);
    this.state = {
      //newValue input by user
      newValue : undefined,
      //stores positions(s) of caret to handle reload after onChange end
      caretPosition : {
        start : 0,
        end : 0
      }
    }
  }

  //handler during key press / input
  onChangeHandler = event => {
    let targetValue =  event.currentTarget.textContent;
    //save caret position(s), so can restore when component reloads
    let savedCaretPosition = CaretPositioning.saveSelection(event.currentTarget);
    this.setState({
      "newValue": targetValue,
      "caretPosition" : savedCaretPosition
    }, () => {
      //restore caret position(s)
      CaretPositioning.restoreSelection(document.getElementById("editable"), this.state.caretPosition);
    })
  }

  //handler when user opens input form
  onBlurHandler = event => {
    //some code that sends the "newValue" to be saved, and resets state
  }

  render() {
    //determine which value to show in the div
    let showValue;
    //if there is a new value being input by user, show this value
    if (this.state.newValue !== undefined) {
      showValue = this.state.newValue;
    } else {
      //if prop has no value e.g. null or undefined, use "" placeholder
      if (this.props.value) {
        showValue = this.props.value;
      } else {
        showValue = "";
      }
    }

    return (
    <table>
    <tbody>
      <td>
          <div
            id="editable"
            contentEditable="true"
            suppressContentEditableWarning="true"
            onInput={this.onChangeHandler.bind(this)}
            onBlur={this.onBlurHandler}
          >{showValue}
          </div>
      </td>
     </tbody>
     </table>
    )
  }
}

export default Input;

答案 2 :(得分:0)

在尝试在<td>上可编辑的内容时,我也遇到了这个问题。编辑时光标移到开始处,我尝试了多种方法,但无济于事!

后来,我最终使用了这个“内容可编辑”的React包。

https://github.com/lovasoa/react-contenteditable

以前,我使用的代码是这样的

   <td 
      onInput={(e) =>this.handleInput(e, user, "name", index)}
      contentEditable={user.isEditable}
      className={
        user.isEditable ? "border  border-success" : ""
      }
   >
     {user.name}
   </td>

包含软件包后,我使用以下代码对其进行了更改。现在它可以正常工作了。

<td className={user.isEditable ? "border border-success" : ""}>
   <ContentEditable
      html={user.name}
      disabled={!user.isEditable}
      onChange={(e) =>
      this.handleInput(e, user, "name", index)
      }
      style={{ "text-decoration": "none" }}
   />
 </td>