我们在web开发中，你的应用可能会在不同国家使用，所以需要将相关的错误提示根据本地语言进行相应的提示，也即是所谓的国际化。本文简单的介绍一下，在Gin中如何实现多语言的验证。我们借助validator.v10以及相应的语言包。

集成关键点

  1. 导入需要转换语言包
    • 公共包： "github.com/go-playground/validator/v10"
    • 需要转换的包，比如英文和中文
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   en2 "github.com/go-playground/locales/en"
zh2 "github.com/go-playground/locales/zh"
ut "github.com/go-playground/universal-translator"
en_translations "github.com/go-playground/validator/v10/translations/en"
zh_translations "github.com/go-playground/validator/v10/translations/zh"
  1. 结构体定义不在是 binding,而是validate
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type Person struct {
	Age     int    `form:"age" validate:"required,gt=10"`
	Name    string `form:"name" validate:"required"`
	Address string `form:"address" validate:"required"`
}
  1. 构建语言转换器以及注册
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tans, _ := uni.GetTranslator(local)
tans, _ := uni.GetTranslator(local)
	switch local {
	case "en":
		en_translations.RegisterDefaultTranslations(validate, tans)
	case "zh":
		zh_translations.RegisterDefaultTranslations(validate, tans)
	default:
		en_translations.RegisterDefaultTranslations(validate, tans)
	}

  1. 校验以及获取错误信息

    校验，调用err := validate.Struct(xx)；如果对返回的错误信息进行处理，validator返回的绑定错误信息格式：key = namespace & value = translated error；我们可以一次性获取所有的转换信息或者每次一次，具体如下：

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err := validate.Struct(person)
if err != nil {
    errs := err.(validator.ValidationErrors)
    // 一次性转换所有与的错误信息方式
    fmt.Println(errs.Translate(trans))
    // 每次转换一次
    for _, e := range errs {
			fmt.Println(e.Translate(trans))
    }
}

具体示例

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package main
import (
	"github.com/gin-gonic/gin"
	en2 "github.com/go-playground/locales/en"
	zh2 "github.com/go-playground/locales/zh"
	ut "github.com/go-playground/universal-translator"
	"github.com/go-playground/validator/v10"
	en_translations "github.com/go-playground/validator/v10/translations/en"
	zh_translations "github.com/go-playground/validator/v10/translations/zh"
	"log"
	"net/http"
)

type Person struct {
	Age     int    `form:"age" validate:"required,gt=10"`
	Name    string `form:"name" validate:"required"`
	Address string `form:"address" validate:"required"`
}

// use a single instance , it caches struct info
var (
	uni      *ut.UniversalTranslator
	validate *validator.Validate
)

func multiLangBindingHandler(c *gin.Context) {
	local := c.DefaultQuery("local", "en")
	log.Println("local:", local)
	tans, _ := uni.GetTranslator(local)
	switch local {
	case "en":
		en_translations.RegisterDefaultTranslations(validate, tans)
	case "zh":
		zh_translations.RegisterDefaultTranslations(validate, tans)
	default:
		en_translations.RegisterDefaultTranslations(validate, tans)
	}
	var person Person

	if err := c.ShouldBind(&person); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{
			"message": err.Error(),
		})
		return
	}
	if err := validate.Struct(person); err != nil {

		errs := err.(validator.ValidationErrors)
		sliceErrs := []string{}
		for _, e := range errs {
			// can translate each error one at a time.
			sliceErrs = append(sliceErrs, e.Translate(tans))
		}
		c.JSON(http.StatusBadRequest, gin.H{
			// translate all error at once
			// returns a map with key = namespace & value = translated error
			// NOTICE: 2 errors are returned and you'll see something surprising
			// translations are i18n aware!!!!
			// eg. '10 characters' vs '1 character'
			"message":   errs.Translate(tans),
			"sliceErrs": sliceErrs,
		})
		return
	}
	c.JSON(http.StatusOK, gin.H{
		"personInfo": person,
	})
}

func main() {
	zh := zh2.New()
	en := en2.New()
	uni = ut.New(en, zh)

	validate = validator.New()
	router := gin.Default()
	router.GET("/testMultiLangBinding", multiLangBindingHandler)
	router.Run(":9999")
}

测试

测试案例 测试结果
$ curl -X GET "localhost:9999/testMultiLangBinding" {"sliceErrs":["Age is a required field","Name is a required field","Address is a required field"]}
$ curl -X GET "localhost:9999/testMultiLangBinding?local=zh&age=12&name=yunfeng&address=wuhan" {"personInfo":{"Age":12,"Name":"yunfeng","Address":"wuhan"}}
$ curl -X GET "localhost:9999/testMultiLangBinding?local=zh&age=12&name=yunfeng&address=wuhan" {"personInfo":{"Age":12,"Name":"yunfeng","Address":"wuhan"}}
$ curl -X GET "localhost:9999/testMultiLangBinding?local=zh" {"message":{"Person.Address":"Address为必填字段","Person.Age":"Age为必填字段","Person.Name":"Name为必填字段"},"sliceErrs":["Age为必填字段","Name为必填字段","Address为必填字段"]}

参考资料

validator.v10
Translations & Custom Errors