Vue 阻止data里的值被修改为null等

采用计算属性的方式进行处理，get时如果为禁止类型 默认返回 不是正常返回

set时如果为禁止类型设置默认或者返回，正确正常赋值

<template>
  <el-form-item label="附件" prop="attachment">
    <el-input v-model="attachment" />
  </el-form-item>
</template>

<script>
export default {
  data() {
    return {
      formData: {
        attachment: "",
      },
    };
  },
  computed: {
    attachment: {
      set(value) {
        if (!value || value === undefined) {
          return;
        }
        this.formData.attachment = value;
      },
      get() {
        return this.formData.attachment ? this.formData.attachment : "";
      },
    },
  },
};
</script>