小编uly*_*lyC的帖子

当我刚刚Gin从 v1.4.0 升级到 v1.5.0 时，我像往常一样使用“BindJSON”函数，并抛出此错误。

2019/11/29 11:44:13 [Recovery] 2019/11/29 - 11:44:13 panic recovered:
Undefined validation function 'exists' on field 'FirstName'
...

这是我的代码：

package main

import (
    "github.com/gin-gonic/gin"
)

type User struct {
    FirstName *string `json:"fn" binding:"exists"` 
}

    
func main(){
    router := gin.Default()
    router.POST("/register", func(c *gin.Context) {
        var user User
        if err := c.BindJSON(&user); err != nil {
            c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{
                    "error": "first name cannot be empty",
                   })
            return
        }
    })

    router.Run(":8080")
}