Gin 使用示例（十一）：自定义表单验证器

我们还可以注册自定义的表单验证器，示例代码如下（src/gin-demo/examples/validator.go）：

package main

import (
  "net/http"
  "time"

  "github.com/gin-gonic/gin"
  "github.com/gin-gonic/gin/binding"
  "gopkg.in/go-playground/validator.v9"
)

// Booking 中包含了绑定的表单请求字段和验证规则
type Booking struct {
  CheckIn  time.Time `form:"check_in" binding:"required,bookabledate" time_format:"2006-01-02"`
  CheckOut time.Time `form:"check_out" binding:"required,gtfield=CheckIn" time_format:"2006-01-02"`
}

var bookableDate validator.Func = func(fl validator.FieldLevel) bool {
  date, ok := fl.Field().Interface().(time.Time)
  if ok {
    today := time.Now()
    if today.After(date) {
      return false
    }
  }
  return true
}

func getBookable(c *gin.Context) {
  var b Booking
  if err := c.ShouldBindWith(&b, binding.Query); err == nil {
    c.JSON(http.StatusOK, gin.H{"message": "预定日期有效!"})
  } else {
    c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
  }
}

func main() {
  route := gin.Default()

  // 注册新的自定义验证规则
  if v, ok := binding.Validator.Engine().(*validator.Validate); ok {
    v.RegisterValidation("bookabledate", bookableDate)
  }

  route.GET("/bookable", getBookable)
  route.Run(":8085")
}

启动服务器，测试结果如下：