element-ui & form ref bug All In One

element-ui & form ref bug All In One

<script src="//unpkg.com/vue/dist/vue.js"></script>
<script src="//unpkg.com/element-ui@2.15.2/lib/index.js"></script>
<h1>"[Vue warn]: Error in v-on handler: 'TypeError: Cannot read property 'validate' of undefined'</h1>
<hr>
<div id="app">
<!--  ref="ruleForm"  -->
<el-form :model="ruleForm" :rules="rules" ref="ruleFormBug" label-width="100px" class="demo-ruleForm">
  <el-form-item label="活动名称" prop="name">
    <el-input v-model="ruleForm.name"></el-input>
  </el-form-item>
  <el-form-item label="活动区域" prop="region">
    <el-select v-model="ruleForm.region" placeholder="请选择活动区域">
      <el-option label="区域一" value="shanghai"></el-option>
      <el-option label="区域二" value="beijing"></el-option>
    </el-select>
  </el-form-item>
  <el-form-item label="活动时间" required>
    <el-col :span="11">
      <el-form-item prop="date1">
        <el-date-picker type="date" placeholder="选择日期" v-model="ruleForm.date1" style="width: 100%;"></el-date-picker>
      </el-form-item>
    </el-col>
    <el-col class="line" :span="2">-</el-col>
    <el-col :span="11">
      <el-form-item prop="date2">
        <el-time-picker placeholder="选择时间" v-model="ruleForm.date2" style="width: 100%;"></el-time-picker>
      </el-form-item>
    </el-col>
  </el-form-item>
  <el-form-item label="即时配送" prop="delivery">
    <el-switch v-model="ruleForm.delivery"></el-switch>
  </el-form-item>
  <el-form-item label="活动性质" prop="type">
    <el-checkbox-group v-model="ruleForm.type">
      <el-checkbox label="美食/餐厅线上活动" name="type"></el-checkbox>
      <el-checkbox label="地推活动" name="type"></el-checkbox>
      <el-checkbox label="线下主题活动" name="type"></el-checkbox>
      <el-checkbox label="单纯品牌曝光" name="type"></el-checkbox>
    </el-checkbox-group>
  </el-form-item>
  <el-form-item label="特殊资源" prop="resource">
    <el-radio-group v-model="ruleForm.resource">
      <el-radio label="线上品牌商赞助"></el-radio>
      <el-radio label="线下场地免费"></el-radio>
    </el-radio-group>
  </el-form-item>
<!-- 为什么要在 DOM 上使用 validator: validateDesc,才可以 ???  -->
<el-form-item
    :rules="[
      {
          message: '请填写活动形式',
          trigger: 'blur',
          validator: validateDesc,
      },
    ]"
    label="活动形式"
    prop="desc">
    <el-input
      type="textarea"
      v-model="ruleForm.desc"
      placeholder="请输入"
      @blur="descHandler"
      @keyup.enter.native="descHandler">
    </el-input>
</el-form-item>
<!-- <el-form-item
    label="活动形式"
    prop="desc">
    <el-input
      type="textarea"
      v-model="ruleForm.desc"
      placeholder="请输入"
      @blur="descHandler"
      @keyup.enter.native="descHandler">
    </el-input>
</el-form-item> -->
  
  <el-form-item>
    <el-button type="primary" @click="submitForm('ruleFormBug')">立即创建</el-button>
    <el-button @click="resetForm('ruleFormBug')">重置</el-button>
<!--     <el-button type="primary" @click="submitForm('ruleForm')">立即创建</el-button>
    <el-button @click="resetForm('ruleForm')">重置</el-button> -->
  </el-form-item>
</el-form>
</div>

var Main = {
    data() {
      return {
        ruleForm: {
          name: '',
          region: '',
          date1: '',
          date2: '',
          delivery: false,
          type: [],
          resource: '',
          desc: ''
        },
        rules: {
          name: [
            { required: true, message: '请输入活动名称', trigger: 'blur' },
            { min: 3, max: 5, message: '长度在 3 到 5 个字符', trigger: 'blur' }
          ],
          region: [
            { required: true, message: '请选择活动区域', trigger: 'change' }
          ],
          date1: [
            { type: 'date', required: true, message: '请选择日期', trigger: 'change' }
          ],
          date2: [
            { type: 'date', required: true, message: '请选择时间', trigger: 'change' }
          ],
          type: [
            { type: 'array', required: true, message: '请至少选择一个活动性质', trigger: 'change' }
          ],
          resource: [
            { required: true, message: '请选择活动资源', trigger: 'change' }
          ],
          desc: [
            {
              // required: true,
              message: '请填写活动形式', 
              trigger: 'blur',
              // validator: validateDesc,
              // 为什么要在 DOM 上使用 validator: validateDesc,才可以 ???
            }
          ]
        }
      };
      // ✅ 自动表单校验只会校验 required: true 的字段
      // 如果需要给，非 required 的字段，手动校验，需要写很多东西 ， holy shit
      // 手动触发 blur 校验，??? 非必填为什么要校验 ???
    },
    methods: {
      validateDesc (rule, value, callback) {
          // console.log('rule =', rule);
          // console.log('value =', value);
          // console.log('callback =', callback);
          console.log('2. 显示表单校验结果，message');
          if (this.errorMessage) {
              callback(new Error(this.errorMessage));
          } else {
              callback();
              // 自动校验， 没有 errorMessage ❌, test throw error
              // callback(new Error('自动校验， 没有 errorMessage ❌'));
          }
      },
      // 手动触发校验
      descHandler () {
          // 1. 同步代码，优先级最高
          console.log('1. 手动触发校验 desc');
          if(!this.ruleForm.desc) {
              this.errorMessage = '请输入 Desc';
          }
          const key = 'desc';
          this.validateFieldByKey(key);
      },
      validateFieldByKey (key = '') {
          const formName = 'ruleFormBug';
          if(key) {
              this.$refs[formName].validateField(key);
          }
      },
      async asyncValidateFiled () {
          // 3. 异步代码，宏任务，优先级更低
          setTimeout(() => {
              console.log('3. delay 表单的异步校验，为 Async API 手动校验流出返回数据的时间');
          }, 0);
          return {};
      },
      async submitForm(formName = 'ruleFormBug') {
        // 手动触发校验
        this.descHandler();
        // 手动触发 Asycn 校验
        await this.asyncValidateFiled();
        // delay async form validate
        setTimeout(() => {
           console.log('4. 异步代码，宏任务 ？？？');
        }, 0);
        // await this.$refs[formName].validate((valid) => {
        // this.$refs[formName].validate((valid) => {
        //   if (valid) {
        //     alert('submit!');
        //   } else {
        //     // 2. 异步代码，微任务，优先级低
        //     console.log('2. error submit ❌');
        //     return false;
        //   }
        // });
        setTimeout(() => {
          this.$refs[formName].validate((valid) => {
            if (valid) {
              alert('submit!');
            } else {
              // 5. 异步代码，宏任务嵌套微任务，优先级最低
              console.log('5. error submit ❌');
              return false;
            }
          });
        }, 0);
      },
      resetForm(formName) {
        this.$refs[formName].resetFields();
      }
    }
  }
var Ctor = Vue.extend(Main)
new Ctor().$mount('#app')

refs

https://github.com/xgqfrms/vue/issues/165

https://codepen.io/xgqfrms/pen/rNyogpd?editors=1011

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