vue使用render函数创建一个input组件

父组件：

<template>
    <test ref="test" :testData="testData"></test>
    <el-button @click="showTestData">点击</el-button>
</template>
<script>
    import test from './text.vue';
    export default {
        components: {test},
        data() {
          return {
            testData: '2233',
          }
        },
        methods: {
          showTestData() {
              this.testData = this.$refs.test.change();
              console.log(this.testData);
          }
        }
    }
</script>

子组件 test.vue

<script>
  export default {
    render: function(createElement) {
      let _self = this
      return createElement('input', {
        domProps: {
          value: _self.testData1
        },
        on: {
          input: function (event) {
            _self.testData1 = event.target.value
          }
        }
      })
    },
    props: ['testData'],
    data() {
      return {
        testData1: ''
      }
    },
    methods: {
      change() {
        return this.testData1;
      }
    },
    mounted() {
      this.testData1 = this.testData;
    }
  }
</script>