【Go】Gin 自定义参数校验和错误信息

package main

import (
	"errors"
	"fmt"
	"github.com/gin-gonic/gin"
	"github.com/gin-gonic/gin/binding"
	"github.com/go-playground/validator/v10"
	"net/http"
	"reflect"
	"strings"
)

type Body struct {
	Name string `json:"name" binding:"oneof=vk vksir" err:"one of vk,vksir"`
	Age  int    `json:"age" binding:"BodyAgeValidate" err:"only 18"`
}

func BodyAgeValidate(f validator.FieldLevel) bool {
	value := f.Field().Int()
	if value != 18 {
		return false
	}
	return true
}

func GetValidateErr(obj any, rawErr error) error {
	validationErrs, ok := rawErr.(validator.ValidationErrors)
	if !ok {
		return rawErr
	}
	var errString []string
	for _, validationErr := range validationErrs {
		field, ok := reflect.TypeOf(obj).FieldByName(validationErr.Field())
		if ok {
			if e := field.Tag.Get("err"); e != "" {
				errString = append(errString, fmt.Sprintf("%s: %s", validationErr.Namespace(), e))
				continue
			}
		}
		errString = append(errString, validationErr.Error())
	}
	return errors.New(strings.Join(errString, "\n"))
}

func ping(c *gin.Context) {
	b := Body{}
	if err := c.ShouldBindJSON(&b); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"detail": GetValidateErr(b, err).Error()})
		return
	}
	c.JSON(http.StatusOK, gin.H{})
}

func main() {
	e := gin.Default()
	if v, ok := binding.Validator.Engine().(*validator.Validate); ok {
		v.RegisterValidation("BodyAgeValidate", BodyAgeValidate)
	}
	e.GET("/ping", ping)
	e.Run("127.0.0.1:8080")
}