uni-app解决focus伪元素不生效（不聚焦）源码

问题梳理：在uni-app中，使用input标签，编译后会自动转化为uni-input组件，导致focus伪元素不生效。

<template>
  <view>
    <input 
    type="text" class="input" placeholder="点击之后聚焦"
    @focus="addFocus('myInput')" @blur="removeFocus('myInput')" ref="myInput"
    >
  </view>
</template>
<script>
  export default {
    methods: {
      addFocus(rf){
        this.$refs[rf].$el.classList.add("focus-input");
      },
      removeFocus(rf){
        this.$refs[rf].$el.classList.remove("focus-input");
      }
    }
  }
</script>
<style>
  .input{
    border: 1px red solid;
  }
  .focus-input{
    border: 1px blue solid;
  }
</style>
<template>
  <view>
    <input 
    type="text" class="input" placeholder="点击之后聚焦"
    @focus="addFocus('myInput')" @blur="removeFocus('myInput')" ref="myInput"
    >
  </view>
</template>

<script>
  export default {
    methods: {
      addFocus(rf){
        this.$refs[rf].$el.classList.add("focus-input");
      },
      removeFocus(rf){
        this.$refs[rf].$el.classList.remove("focus-input");
      }
    }
  }
</script>

<style>
  .input{
    border: 1px red solid;
  }
  .focus-input{
    border: 1px blue solid;
  }
</style>
<template>
	<view>
		<input 
		type="text" class="input" placeholder="点击之后聚焦"
		@focus="addFocus('myInput')" @blur="removeFocus('myInput')" ref="myInput"
		>
	</view>
</template>

<script>
	export default {
		methods: {
			addFocus(rf){
				this.$refs[rf].$el.classList.add("focus-input");
			},
			removeFocus(rf){
				this.$refs[rf].$el.classList.remove("focus-input");
			}
		}
	}
</script>

<style>
	.input{
		border: 1px red solid;
	}
	.focus-input{
		border: 1px blue solid;
	}
</style>