基于Vue实现一个textarea幽灵建议功能

<label class="container">
  <textarea></textarea>
  <div class="ghost-content"></div>
</label>

.container {
  position: relative;
  display: block;
  width: 300px;
  height: 200px;
  font-size: 14px;
  line-height: 21px;
}
.container textarea {
  width: 100%;
  height: 100%;
  padding: 0;
  border: 0;
  font: inherit;
  color: #212121;
  background-color: #fff;
  outline: none;
}
.ghost-content {
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  bottom: 0;
  color: #212121;
  opacity: 0.3;
}

import { ref } from 'vue'
const content = ref('') // 输入框内容
const ghostContent = ref('') // 建议内容
const suggestions = ['你好啊', '怎么学编程'] // 建议列表
const handleInput = () => {
  ghostContent.value = '' // 内容变化时，清空建议
  // 如果为空或者建议内容改变，则不进行后续匹配
  if (content.value === '') {
    return
  }
  const suggestion = suggestions.find((item) => item.startsWith(content.value))
  if (suggestion) {
    ghostContent.value = suggestion
  }
}
const handleTabKeydown = () => {
  // 监听tab键按下，将输入框内容设置为建议内容，同时清空建议内容
  content.value = ghostContent.value
  ghostContent.value = ''
}

// 重复部分省略
// ...
const ghostHTML = ref('') // 建议内容HTML
const handleInput = () => {
  ghostContent.value = ''
  ghostHTML.value = ''
  if (content.value === '' || fromSuggestion) {
    fromSuggestion && (fromSuggestion = false)
    return
  }
  const suggestion = suggestions.find((item) => item.startsWith(content.value))
  if (suggestion) {
    ghostContent.value = suggestion
    ghostHTML.value = suggestion.replace(content.value, `<span>${content.value}</span>`) + ' →' // 显示内容替换
  }
}
const handleTabKeydown = () => {
  content.value = ghostContent.value
  ghostContent.value = ''
  ghostHTML.value = ''
}