golang gin-gonic and splitting files in package

I am quite new to go and try to learn, I am setting up an application with a gin-gonic server.
I managed to have it to work with everything in on main package, I would like to organize it better with all the apirest related in a package (which I manage) AND to split each group CRUD by file.

so in the "main" file of the package within the init function, I defined :

Router := gin.New()
Router.Use(gin.Logger())
Router.Use(gin.Recovery())

and I though that I would be able in each other files of the package to use it like that :

v1 := Router.Group("/api/v1/todos")
v1.Use(AuthRequired())
{
	v1.POST("/", CreateTodo)
	v1.GET("/", FetchAllTodo)
	v1.GET("/:id", FetchSingleTodo)
	v1.PUT("/:id", UpdateTodo)
	v1.DELETE("/:id", DeleteTodo)
}

or

packagename.Router.Group

but none are working and I get :

> undefined: Router in Router.Group

Stéphane
PS : I did setup a sub folder for the package and I am able to go build it if it's in one file.

I though that the solution was to declare the Router variable as *gin.Engine but while it's compiling fine, I get a panic error on the Router.Group call

let me post some more part of code :

maincode.go :

package main

import (
    "fmt"
    "./apirest"
    "github.com/braintree/manners"
)

func main(){
    fmt.Printf("hello world.\n")
    //router.Run()
	manners.ListenAndServe(":8080", apirest.Router)
}

Then I split the apirest package in 2 files :

apirest.go (I did manually cleanup, maybee I missed an import) :

package apirest

import (
	"fmt"
	"github.com/gin-gonic/gin"
	"github.com/braintree/manners"
	"os"
	"os/signal"
)

//Router pour gérer l'api
var Router *gin.Engine

/*
	MAIN FUNCTION
*/
func init() {

	Router := gin.New()
    Router.Use(gin.Logger())
    Router.Use(gin.Recovery())

    c := make(chan os.Signal, 1)
	signal.Notify(c, os.Interrupt)
	go func(){
		for sig := range c {
			// sig is a ^C, handle it
			fmt.Printf("ctl+c catched "+sig.String())
			manners.Close()
		}
	}()

	LoadMonitor()

}

and then the todoCRUD.go file that handle all the declaration, the todoCRUD.go and apirest.go are in the same subfolder apirest (and compile ok) :

package apirest

import (
	"fmt"
	"github.com/gin-gonic/gin"
	"gopkg.in/validator.v2"
	"github.com/jinzhu/gorm"
	"strconv"
	"net/http"
	"time"
)

//Todo definition d'un element todo
type Todo struct {
	gorm.Model
    CreatedAt   time.Time
    UpdatedAt   time.Time
	OwnerID		int    `json:"ownerid"  validate:"nonzero"`
	URL			string `json:"url"`
}

//TransformedTodo version pour le retour d'api sans certaines infos
type TransformedTodo struct {
	ID        	uint   `json:"id"`
    CreatedAt   time.Time
    UpdatedAt   time.Time
    OwnerID		uint   `json:"ownerid"`
	URL         string `json:"url"`   
}

//LoadTodo permet de lancer le mappage todos
func LoadTodo(){
    v1 := Router.Group("/api/v1/todos")
	{
		v1.POST("/", CreateTodo)
		v1.GET("/", FetchAllTodo)
		v1.GET("/:id", FetchSingleTodo)
		v1.PUT("/:id", UpdateTodo)
		v1.DELETE("/:id", DeleteTodo)
	}
}

//CreateTodo génération d'un todo
func CreateTodo(c *gin.Context) {

	owner, _ := strconv.Atoi(c.PostForm("ownerid"))
	todo := Todo{
		OwnerID: owner,
        URL: c.PostForm("url"),
    };
	v := validator.NewValidator()
	if errs := v.Validate(todo); errs!=nil {
		errors := errs.(validator.ErrorMap)
		var errOuts []string
    	for f, e := range errors {
        	errOuts = append(errOuts, fmt.Sprintf("\t - %s (%v)\n", f, e))
    	}
		//c.JSON(500, gin.H{"Error": errs.Error()})
		c.JSON(500, gin.H{"Erreur sur le(s) champ(s) : ": errOuts})
	} else {
		
		db, _ := Database()
		defer db.Close()
		db.Save(&todo)
		
		c.JSON(http.StatusCreated, gin.H{"status" : http.StatusCreated, "message" : "Todo item created successfully!", "resourceId": todo.ID})
	}
}

//FetchAllTodo récupération de tous les todos
func FetchAllTodo(c *gin.Context) {
	var todos []Todo
	var _todos []TransformedTodo
	
	db, _ := Database()
	defer db.Close()
	db.Find(&todos)

	if (len(todos) <= 0) {
		c.JSON(http.StatusNotFound, gin.H{"status" : http.StatusNotFound, "message" : "No todo found!"})
		return
	}

	//transforms the todos for building a good response,
	//je peux choisir des champs a ne pas display
	for _, item := range todos {
		status := false
		if (item.Status == 1) {
			status = true
		} else {
			status = false
		}
		_todos = append(_todos, TransformedTodo{ID: item.ID, URL:item.URL})
	}
	c.JSON(http.StatusOK, gin.H{"status" : http.StatusOK, "data" : _todos})
}

//FetchSingleTodo Récupération d'un seul todo en fonction de son id
func FetchSingleTodo(c *gin.Context) {
	var todo Todo
	todoID := c.Param("id")

	db, _ := Database()
	defer db.Close()
	db.First(&todo, todoID)

	if (todo.ID == 0) {
		c.JSON(http.StatusNotFound, gin.H{"status" : http.StatusNotFound, "message" : "No todo found!"})
		return
	}
	
	_todo := TransformedTodo{ID: todo.ID, URL:todo.URL}
	c.JSON(http.StatusOK, gin.H{"status" : http.StatusOK, "data" : _todo})
}

//UpdateTodo Mise à jour d'un todo
func UpdateTodo(c *gin.Context) {
	var todo Todo
	todoID := c.Param("id")
	db, _ := Database()
	defer db.Close()
	db.First(&todo, todoID)

	if (todo.ID == 0) {
		c.JSON(http.StatusNotFound, gin.H{"status" : http.StatusNotFound, "message" : "No todo found!"})
		return
	}

	db.Model(&todo).Update("title", c.PostForm("title"))
	db.Model(&todo).Update("completed", c.PostForm("completed"))
	c.JSON(http.StatusOK, gin.H{"status" : http.StatusOK, "message" : "Todo updated successfully!"})
}


//DeleteTodo Suppression d'un todo
func DeleteTodo(c *gin.Context) {
	var todo Todo
	todoID := c.Param("id")
	db, _ := Database()
	defer db.Close()
	db.First(&todo, todoID)

	if (todo.ID == 0) {
		c.JSON(http.StatusNotFound, gin.H{"status" : http.StatusNotFound, "message" : "No todo found!"})
		return
	}

	db.Delete(&todo)
	c.JSON(http.StatusOK, gin.H{"status" : http.StatusOK, "message" : "Todo deleted successfully!"})
}

The Idea is to have a xxxxCRUD.go file for each entity to handle but the whole folder in the same package.

the exact errror is :

> PS D:\www\developpement> go run .\maincode.go [GIN-debug] [WARNING]
> Running in "debug" mode. Switch to "release" mode in production.
> - using env: export GIN_MODE=release
> - using code: gin.SetMode(gin.ReleaseMode)
>
> panic: runtime error: invalid memory address or nil pointer
> dereference [signal 0xc0000005 code=0x0 addr=0x0 pc=0x46cc0f]
>
> goroutine 1 [running]: panic(0x831880, 0xc04200a080)
> C:/Go/src/runtime/panic.go:500 +0x1af
> /D/www/developpement/apirest.LoadTodo()
> D:/www/developpement/apirest/todoCRUD.go:33 +0x2f [Router.Group]
> /D/www/developpement/apirest.init.1()
> D:/www/developpement/apirest/apirest.go:73 +0x220 [LoadTodo()]
> /D/www/developpement/apirest.init()
> D:/www/developpement/apirest/todoCRUD.go:190 +0x80 [last line] main.init()
> D:/www/developpement/maincode.go:13 +0x3a [manners.ListenAndServe(":8080", apirest.Router)] exit status 2

I hope that this will help to understand !

Thanks for your time and help !

Stéphane

I did manage to make it work by "sending" the router in the LoadTodo function :

in apirest.go :

LoadTodo(Router)

and in todoCRUD.go :

func LoadTodo(r *gin.Engine){

and it's working fine ... I hope I didn't bring a bug failure in the code ...

Stéphane