最近在开发一个移动端商城项目，用到了有赞的 vant ，因为最近大都采用 element ui 在做PC端的东西，对比来说，vant的完成度还是偏低了点，很多细节都虽然都实现了接口，但是想使用得自己去想办法，没办法拿来即用。昨天用到 Uploader 图片上传 如是，提供了file回调，却没有提供上传功能，我必须给他加2个函数实现axios提交才能用，还有今天用到表单验证这块，它的 Field组件 虽然给了error-message的错误提示接口，但是没有内置表单验证功能。
element ui 采用 async-validator 实现表单验证，我也基于这个组件进行扩展，async-validator不支持细粒化验证，于是先对它进行扩展

validator.js

import asyncValidator from 'async-validator'

class validator {
  /**
   * 构造
   * @param rules object async-validator rules
   * @param data  初始对象
   */
  constructor(rules, data) {
    this.setData(data);
    this.setRules(rules);
  }

  /**
   * 重新定义初始对象
   * 也可以直接修改实例的data
   * validator.data = newData
   * @param data
   */
  setData(data) {
    this.data = data;
  }

  /**
   * 设定规则
   * @param rules rules object async-validator rules
   * @param cover 是否替换旧规则
   */
  setRules(rules, {cover} = {}) {
    if (cover === undefined || cover) {
      this.validators = {};
    }
    for (let attr in rules) {
      const rule = {};
      rule[attr] = rules[attr];
      this.validators[attr] = new asyncValidator(rule);
    }
  }

  /**
   * 执行验证
   * @param callback(errors, fields)
   * @param data 可选 传空将验证构造data 传string或数组验证构造data的响应字段
   * 以上参数顺序可互转
   */
  validate(callback, data) {
    let cb,d;
    if (typeof callback === 'function' ){
      cb = callback;
      d = data;
    }else if (typeof data === 'function' ){
      cb = data;
      d = callback;
    }

    let _d = d;

    if (this.data) {
      if (!d) {
        _d = this.data;
      } else if (typeof d === 'string') {
        _d = {};
        _d[d] = this.data[d]
      } else if (Array.isArray(d)) {
        _d = {};
        d.forEach(attr => {
          _d[attr] = this.data[attr]
        })
      }
    }

    const err = [];

    if (_d) {
      for (let attr in _d) {
        if (this.validators[attr]) {
          const o = {};
          o[attr] = _d[attr];
          this.validators[attr].validate(o, (error) => {
            if (error) {
              err.push(error[0])
            }
          })
        }
      }
    }

    cb && cb(err.length > 0, err)

  }
}

export default function (rules, data) {
  return new validator(rules, data)
}

demo.vue

<template>
  <div>
    <van-cell-group>
      <van-field
          placeholder="名称/姓名"
          label="名称"
          v-model="data.name"
          :error-message="errorMsg.name"
      ></van-field>
      <van-field
          type="tel"
          placeholder="请输入手机号码"
          label="手机"
          v-model="data.mobile"
          :error-message="errorMsg.mobile"
          @click-icon="data.mobile = ''"
          icon="clear"
      ></van-field>
      <van-field
          center
          v-model="data.code"
          label="短信验证码"
          placeholder="请输入验证码"
          icon="clear"
          :error-message="errorMsg.code"
          @click-icon="data.code = ''"
      >
        <van-button
            slot="button"
            size="small"
            :disabled="countdown > 0"
            @click="sendMobileCode"
            type="primary">
          {{ countdown ? countdown + 's' : '发送'}}
        </van-button>
      </van-field>
    </van-cell-group>
    <div class="pad-all mar-top">
      <van-button
          block
          type="primary"
          @click="submit">
        立即注册
      </van-button>
      <van-button
          block
          class="mar-top"
          @click="reset">
        重置
      </van-button>
    </div>
  </div>
</template>
<script>
  import {Field, CellGroup, Cell, Button, Toast} from 'vant';
  import validator from './validator.js'

  export default {
    name: 'Demo',
    components: {
      [Field.name]: Field,
      [Button.name]: Button,
      [Cell.name]: Cell,
    },
    data() {
      return {
        countdown: 0,
        data: {
          name: '',
          mobile: '',
          code: '',
        },
        errorMsg: {
          name: '',
          mobile: '',
          code: '',
        },
        rules: {
          name: [
            {required: true, message: '请输入名称'}
          ],
          mobile: [
            {
              validator: (rule, value, callback) => {
                if (!value) {
                  callback('请输入手机号码');
                } else if (/^[1][0-9]{10}$/.test(value)) {
                  callback();
                } else {
                  callback('请输入正确的手机号码');
                }
              }
            }
          ],
          code: [
            {required: true, message: '请输入验证码'}
          ]
        },
      }
    },
    methods: {
      sendMobileCode() {
        this.validate(errors => {
          if (!errors) {
            Toast('发送成功');
            this.countdown = 60;
            this.countdownSubtract();
          }
        }, 'mobile')
      },
      countdownSubtract() {
        if (this.countdown > 0) {
          setTimeout(() => {
            this.countdown -= 1;
            this.countdownSubtract()
          }, 1000)
        }
      },
      /**
       * 清除验证提示
       * @param attrs
       */
      resetField(attrs) {
        attrs = !attrs ? Object.keys(this.errorMsg) : ( Array.isArray(attrs) ? attrs : [attrs]);
        attrs.forEach(attr => {
          this.errorMsg[attr] = ''
        })
      },
      /**
       * 验证方法
       * @param callback
       * @param data
       */
      validate(callback, data) {
        this.validator.validate((errors, fields) => {
          this.resetField();
          if (errors) {
            fields.forEach(item => {
              this.errorMsg[item.field] = item.message
            })
          }
          callback && callback(errors, fields)
        }, data);
      },
      submit() {
        this.validate((errors, fields) => {

        })
      },
      reset() {
        this.data = {
          name: '',
          code: '',
          mobile: '',
        };
        this.validator.setData(this.data);
        this.resetField();
      },
    },
    created() {
      this.validator = validator(this.rules, this.data);
    },
  }
</script>

还有待完善的地方，凑合着能用了