自定义验证器
Gin 使用 go-playground/validator 进行字段级验证。除了内置的验证器(如 required、email、min、max),你还可以注册自己的自定义验证函数。
下面的示例注册了一个 bookabledate 验证器,用于拒绝过去的日期,确保预订的入住和退房日期始终在未来。
package main
import ( "net/http" "time"
"github.com/gin-gonic/gin" "github.com/gin-gonic/gin/binding" "github.com/go-playground/validator/v10")
// Booking contains binded and validated data.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.After(date) { 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(":8085")}
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()}) }}测试
# Both dates are in the future and check_out > check_incurl "http://localhost:8085/bookable?check_in=2118-04-16&check_out=2118-04-17"# Output: {"message":"Booking dates are valid!"}
# check_out is before check_in -- fails gtfield validationcurl "http://localhost:8085/bookable?check_in=2118-03-10&check_out=2118-03-09"# Output: {"error":"Key: 'Booking.CheckOut' Error:Field validation for 'CheckOut' failed on the 'gtfield' tag"}