js: ElementUI表单验证validate和validateField

Function(callback: Function(boolean, object))

Function(props: array | string, callback: Function(errorMessage: string))

<template>
  <el-form
    ref="form"
    :model="form"
    :rules="rules"
    label-width="80px"
    size="mini"
  >
    <el-form-item
      label="姓名"
      prop="name"
    >
      <el-input v-model.trim="form.name"></el-input>
    </el-form-item>
    <el-form-item
      label="年龄"
      prop="age"
    >
      <el-input v-model.number="form.age"></el-input>
    </el-form-item>
    <el-form-item
      label="学校"
      prop="school"
    >
      <el-input v-model.trim="form.school"></el-input>
    </el-form-item>
    <el-form-item>
      <el-button
        type="primary"
        @click="validate"
      >校验全部</el-button>
      <el-button
        type="primary"
        @click="validateField"
      >校验单个字段</el-button>
      <el-button
        type="primary"
        @click="validateFields"
      >校验多个字段</el-button>
    </el-form-item>
  </el-form>
</template>
<script>
// created at 2021-09-23
export default {
  name: 'TestForm',
  data() {
    return {
      form: {
        name: '',
        age: '',
        school: '',
      },
      rules: {
        name: [{ required: true, message: '请输入姓名', trigger: 'blur' }],
        age: [
          {
            required: true,
            message: '请输入年龄',
            trigger: 'blur',
          },
          { type: 'number', message: '年龄必须为数字值', trigger: 'blur' },
        ],
        school: [{ required: true, message: '请输入学校', trigger: 'blur' }],
      },
    };
  },
  methods: {
    /**
     * 校验全部字段
     */
    validate() {
      this.$refs['form'].validate((valid) => {
        console.log(valid); // true/false
      });
    },
    /**
     * 校验单个字段
     */
    validateField() {
      this.$refs['form'].validateField('name', (errorMessage) => {
        console.log(errorMessage);
        let valid = errorMessage == '' ? true : false;
        console.log(valid); // true/false
      });
    },
    /**
     * 校验多个字段
     */
    validateFields() {
      // 需要校验的字段
      let fieldsToValidate = ['name', 'age'];
      // 将回调转换为Promise
      Promise.all(
        fieldsToValidate.map((field) => {
          return new Promise((resolve, reject) => {
            this.$refs['form'].validateField(field, (errorMessage) => {
              resolve(errorMessage);
            });
          });
        })
      ).then((errorMessages) => {
        console.info(errorMessages);
        //  ['请输入姓名', '请输入年龄']
        // errorMessages 里是各个字段的验证错误信息, 如果数组里全为空串则所有验证通过
        // 判断errorMessages 里是否全是空串
        let valid = errorMessages.every((errorMessage) => {
          return errorMessage == '';
        });
        console.log(valid); // true/false
      });
    },
  },
};
</script>
<style lang="scss" scoped>
</style>