Vue实现富文本插入Emoji

介绍

项目中在聊天页面，要求实现一个类似 youtube 的 emoji 功能,发送后能多端显示一致

需求分析

一个富文本框，支持输入文字，插入 emoji 转成 img ，同时在发送时转成字符串，接收消息，将字符串转成 document node 在页面显示

难点

1. 得焦插入和失焦插入内容时光标位置计算, 参考Range的使用

2. 富文本内容(含 emoji 图片)转字符串, 参考Emoji多端统一处理

3. 字符串消息转成 html (含 emoji 图片)

核心代码

::: code-group

<div
  id="emojiInput"
  ref="editor"
  :class="['emojiInput el-textarea', isallow ? '' : 'notAllow', isInFocus ? 'focus-Bk': 'not-focus', isShowBtn ? 'modify-padding' : '', htmlCount ? '' : 'emojiInputEmpty']"
  :contenteditable="isallow"
  :placeholder="$t('ModelLive.saySomeThing')"
  @keypress="stopKeyEvent"
  @click="setInputFocus"
  @blur="setInputBlur"
  @focus="getFocus"
  @keypress.enter="pressEnter"
/>

// 富文本插入
appendToEditor(item) {
  // 字数超限
  if (this.inputStatusCheck()) {
    return false
  }
  this.getCurrentRange()
  const unicode = item.unicode
  const doc = document.createElement('img')
  const imgSrc = `${this.Config.emojiHost}${item.Url}`
  const style = `width: ${this.emojiImgWidth}px;height: ${this.emojiImgWidth}px;vertical-align: top;margin-left:2px;margin-right:2px;`
  doc.setAttribute('src', imgSrc)
  doc.setAttribute('data-unicodeurl', item.Url)
  doc.setAttribute('class', 'img-emoji')
  doc.setAttribute('alt', unicode)
  doc.setAttribute('style', style)
  this.range.insertNode(doc)
}

// 字数超限
inputStatusCheck() {
  return this.htmlCount >= this.limitCount
}

// 观察editor触发的回调
editorChange() {
  // 浏览器兼容检查
  this.broswerRichtextHack()
  this.isInFocus = true
  this.changeFocusStatus()
  this.getCurrentRange()
  this.updateRange()
  this.scrollToBottom()
  this.htmlCount = this.wcemojiIns.calVNodeCount(this.editor)
  this.isAllnbsp = this.wcemojiIns.checkVnodeAllnbsp(this.editor)
  this.$emit('editorChangeCount', { htmlCount: this.htmlCount, limitCount: this.limitCount })
  this.$emit('editorCheckAllnbsp', this.isAllnbsp)
  this.cutMoreStrAfterPaste()
}

// 判断点击emoji表情插入时当前的range是否在输入框内,是使用getRangeAt(0)，否则构造一个以editor最后节点开始的range
getCurrentRange() {
  if (!this.selection) {
    this.selection = window.getSelection()
  }
  const range = this.selection.getRangeAt(0)
  // 判断是否是div,如果是div判断是否是emojiInput
  if (range.commonAncestorContainer && range.commonAncestorContainer.nodeName === 'DIV') {
    if (range.commonAncestorContainer.id === 'emojiInput') {
      // 针对firefox 删除后追加<br>的hack
      if (range.commonAncestorContainer.firstChild && range.commonAncestorContainer.firstChild.nodeName === 'BR') {
        this.range = this.constructRange()
      } else {
        this.range = range
      }
    } else {
      this.range = this.constructRange()
    }
  }
  // 判断是否是text,如果是text判断是否父节点是emojiInput
  if (range.commonAncestorContainer && range.commonAncestorContainer.nodeName === '#text') {
    if (range.commonAncestorContainer.parentNode.id === 'emojiInput') {
      this.range = range
    } else {
      this.range = this.constructRange()
    }
  }
}

// 自定义构造range
constructRange() {
  const range = document.createRange()
  const dom = document.querySelector('#emojiInput')
  const len = dom.childNodes.length
  let idxStart = 0
  let idxEnd = 0
  let lastNode = ''
  let isAllImg = true
  if (len > 0) {
    isAllImg = this.checkDomChildIsAllImg(dom.childNodes)
    lastNode = dom.childNodes[len - 1]
    if (lastNode.nodeName === 'IMG') {
      if (isAllImg) {
        lastNode = dom
        idxStart = len
        idxEnd = len
      } else {
        idxEnd = 0
      }
    }
    if (lastNode.nodeName === '#text') {
      idxEnd = lastNode.textContent.length
    }
    if (lastNode.nodeName === 'BR') {
      lastNode = dom
    }
  } else {
    lastNode = dom
  }
  range.setStart(lastNode, idxStart)
  range.setEnd(lastNode, idxEnd)
  console.log(range)
  return range
}

// 粘贴后如果超出长度，则删除多余的内容
cutMoreStrAfterPaste() {
  const nodeArr = this.editor.childNodes
  if (this.htmlCount > this.htmlMaxCount) {
    const len = nodeArr.length
    let count = 0
    let str = ''
    for (let i = 0; i < len; i++) {
      const item = nodeArr[i]
      if (count >= this.htmlMaxCount) {
        break
      } else {
        // 要么图片，要么文字
        if (item.nodeName === 'IMG') {
          count += 1
          str += item.outerHTML
        } else {
          const chaNum = this.htmlMaxCount - count
          if (chaNum > item.length) {
            count += item.length
            str += item.textContent
          } else {
            count += chaNum
            str += item.textContent.substr(0, chaNum)
          }
        }
      }
    }
    this.editor.innerHTML = str
  }
}

// 浏览器富文本hack
broswerRichtextHack() {
  const kernel = this.UtilFn.checkKernel()
  // chrome和safari浏览器
  if (kernel === 'safari') {
    // 暂不处理
  }
  // firefox
  if (kernel === 'firefox') {
    const dom = document.querySelector('#emojiInput')
    if (dom.childNodes.length > 0) {
      const firstNode = dom.childNodes[0]
      if (firstNode.nodeName === 'BR' && firstNode.getAttribute('class') !== 'wc-br') {
        dom.childNodes[0].setAttribute('class', 'wc-br')
      }
    }
  }
  // edge
  if (kernel === 'edge') {
    // 暂不处理
  }
}

:::

参考

1. HTMl DOM Range用法
2. Selection和Range参考