gin框架29--自定义验证器

gin框架29--自定义验证器

介绍

本文介绍了如何在gin框架中自定义验证器，并加以案例说明。

案例

源码：

package main

import (
    "net/http"
    "time"

    "github.com/gin-gonic/gin"
    "github.com/gin-gonic/gin/binding"
    "github.com/go-playground/validator/v10"
)

// Booking 包含绑定和验证的数据。
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,bookabledate" 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.Year() > date.Year() || today.YearDay() > date.YearDay() {
            return false
        }
    }
    return true
}

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

    if v, ok := binding.Validator.Engine().(*validator.Validate); ok {
        v.RegisterValidation("bookabledate", bookableDate)
    }

    route.GET("/bookable", getBookable)
    route.Run(":8080")
}

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

注： 官方文档中通过 today.After(date) 作为判断依据，该方法不准确，会导致一直为false， 因此可以调整为 today.Year() > date.Year() || today.YearDay() > date.YearDay()

测试：

http://127.0.0.1:8080/bookable?check_in=2022-04-01&check_out=2022-04-02
{
    "message": "Booking dates are valid!"
}

http://127.0.0.1:8080/bookable?check_in=2022-04-01&check_out=2022-04-01
{
    "error": "Key: 'Booking.CheckOut' Error:Field validation for 'CheckOut' failed on the 'gtfield' tag"
}

说明

​​gin官方文档 自定义验证器​​​​gin-gonic/examples-> Struct level validations​​​​gin自定义验证器转化中文​​