reverse

README

reverse

Go (golang) URL reverse

Simple URL reverse package. It's useful for templates. You can get a URL by a name and params and not depend on URL structure.

It fits to any router. All it does is just stores urls by a name and replace params when you retrieve a URL. To use it you have to add a URL with a name, raw URL with placeholders (params) and a list of these params.

// To set a URL and return raw URL use:
reverse.Add("UrlName", "/url_path/:param1/:param2", ":param1", ":param2")
// OUT: "/url_path/:param1/:param2"

// To set a URL with group (subrouter) prefix and return URL without prefix use:
reverse.AddGr("UrlName", "/url_path", "/:param1/:param2", ":param1", ":param2")
// OUT: "/:param1/:param2"

// Note, that these funcs panic if errors. Instead you can use Urls.Add() and Urls.Reverse() 
// that return errors. Or you can make your own wrapper for them.

// To retrieve a URL by name with given params use:
reverse.Rev("UrlName", "value1", "value2")
// OUT: "/url_path/value1/value2"

// Get raw url by name
reverse.Get("UrlName")
// OUT: "/url_path/:param1/:param2"

// Get all url as map[string]string
reverse.GetAllUrls()

// Get all urls params as map[string][]string
reverse.GetAllParams()

Example for Gin router (https://github.com/gin-gonic/gin):

func main() {
    router := gin.Default()
    
    // URL: "/"
    // To fetch the url use: reverse.Rev("home")
    router.GET(reverse.Add("home", "/"), indexEndpoint)
    
    // URL: "/get/123"
    // With param: c.Param("id")
    // To fetch the URL use: reverse.Rev("get_url", "123")
    router.GET(reverse.Add("get_url", "/get/:id"), getUrlEndpoint)
    

    // Simple group: v1 (each URL starts with /v1 prefix)
    groupName := "/v1"
    v1 := router.Group(groupName)
    {
        // URL: "/v1"
        // To fetch the URL use: reverse.Rev("v1_root")
        v1.GET(reverse.AddGr("v1_root", groupName, ""), v1RootEndpoint)
        
        // URL: "v1/read/cat123/id456"
        // With params (c.Param): catId, articleId
        // To fetch the URL use: reverse.Rev("v1_read", "123", "456")
        v1.GET(reverse.AddGr("v1_read", groupName, "/read/cat:catId/id:articleId", ":catId", ":articleId"), readEndpoint)

        // URL: /v1/login
        // To fetch the URL use: reverse.Rev("v1_login")
        v1.GET(reverse.AddGr("v1_login", groupName, "/login"), loginGetEndpoint)
        
    }

    router.Run(":8080")
}

Example using Goji router:

package main

import (
        "fmt"
        "net/http"
        "github.com/alehano/reverse"
        "github.com/zenazn/goji"
        "github.com/zenazn/goji/web"
)

func hello(c web.C, w http.ResponseWriter, r *http.Request) {
        // We can get reversed URL by it's name and a list of params:
        // reverse.Rev("UrlName", "value1", "value2")

        fmt.Fprintf(w, "Hello, %s", reverse.Rev("HelloUrl", c.URLParams["name"]))
}

func main() {
        // Set a URL and Params and return raw URL to a router
        // reverse.Add("UrlName", "/url_path/:param1/:param2", ":param1", ":param2")

        goji.Get(reverse.Add("HelloUrl", "/hello/:name", ":name"), hello)
        
        // In regexp instead of: re := regexp.MustCompile("^/comment/(?P<id>\\d+)$")
        re := regexp.MustCompile(reverse.Add("DeleteCommentUrl", "^/comment/(?P<id>\\d+)$", "(?P<id>\\d+)$"))
        goji.Delete(re, deleteComment)
        
        goji.Serve()
}

Example for Gorilla Mux

// Original set: r.HandleFunc("/articles/{category}/{id:[0-9]+}", ArticleHandler)
r.HandleFunc(reverse.Add("ArticleCatUrl", "/articles/{category}/{id:[0-9]+}", "{category}", "{id:[0-9]+}"), ArticleHandler)

// So, if we want to retrieve URL "/articles/news/123", we call:
fmt.Println( reverse.Rev("ArticleCatUrl", "news", "123") )

Example subrouters for Chi router:

// Original code
r.Route("/articles", func(r chi.Router) {
	r.Get("/", listArticles)
	r.Route("/{articleID}", func(r chi.Router) {
		r.Get("/", getArticle)
	})
})

// With reverse package
r.Route("/articles", func(r chi.Router) {
	r.Get(reverse.AddGr("list_articles", "/articles", "/"), listArticles)
	r.Route("/{articleID}", func(r chi.Router) {
		r.Get(reverse.AddGr("get_article", "/articles/{articleID}", "/", "{articleID}"), getArticle)
	})
})

// Get a reverse URL:
reverse.Rev("get_article", "123")
// Output: /articles/123/

// One more example (without tailing slashes)
r.Route(reverse.Add("admin.index", "/admin"), func(r chi.Router) {
	r.Get("/", index)

	r.Route(reverse.AddGr("admin.login", "/admin", "/login"), func(r chi.Router) {
		r.Get("/", login)
		r.Post("/", loginPost)
	})
})

Documentation

Index

• Variables
• func Add(urlName, urlAddr string, params ...string) string
• func AddGr(urlName, group, urlAddr string, params ...string) string
• func Clear()
• func Get(urlName string) string
• func GetAllParams() map[string][]string
• func GetAllUrls() map[string]string
• func Rev(urlName string, params ...string) string

Variables

var Urls *urlStore

Functions

func Add

func Add(urlName, urlAddr string, params ...string) string

Adds url to store

func AddGr

func AddGr(urlName, group, urlAddr string, params ...string) string

Adds url with concat group, but returns just urlAddr

func Clear

func Clear()

func Get

func Get(urlName string) string

Gets raw url by name

func GetAllParams

func GetAllParams() map[string][]string

Gets all params

func GetAllUrls

func GetAllUrls() map[string]string

Gets saved all urls

func Rev

func Rev(urlName string, params ...string) string

Reverse url by name