vue2 + elementui 表单自定义校验

例如校验文件是否上传：

data(){
	const validateLogo = (rule, value, callback) => {
      if (!this.formData.UploadFile) {
        callback(new Error("请上传身份证图片"));
      } else {
        callback();
      }
    };
	return {
		rules: {
			// 身份证图片
	        UploadFile: [
	          {
	            required: true,
	            validator: validateLogo,
	            trigger: "change",
	          },
	        ],
		}
		
	}
}