解决vue+ element ui 表单验证有值但验证失败问题

<el-form :model="form" :rules="rules">
<el-form-item label="数据模板" prop="template" >
 <el-col :span="20">
  <el-input type="textarea" v-model="form.template" :rows="8" placeholder="请输入数据模板" :readonly="true" ></el-input>
 </el-col>
</el-form-item>
</el-form>
export default {
data() {
 return {
  form: {
   template: null
  }
  rules: [
   template:{required: true, message: '数据模板不能为空', trigger: 'blur'}
  ]
 }
}
}