langmiddleware

README

Lang Middleware

The Lang Middleware provide a simple way to obtain the prefed language of the client.

How to use

Initialize a new middleware using one of the function provided.

• NewCookieOnly returns a new LangMiddleware configured to use only informations from cookie named
• NewHeaderOnly returns a new LangMiddleware configured to use only informations from accept-language header
• NewHeaderAndCookie returns a new LangMiddleware configured to use informations from both cookie and accept-language header

Then use the Extractor() function to get the http handler.

## Example

package main

import (
	"net/http"
	"github.com/go-chi/chi"
	"github.com/jderail/langmiddleware"
)

func main() {

	lang, _ := langmiddleware.NewCookieOnly("en", []string{"en", "fr"}, "lang-cookie")
	r := chi.NewRouter()
	r.Use(lang.Extractor())
	r.Get("/", func(w http.ResponseWriter, r *http.Request) {
		w.Write([]byte(r.Context().Value(langmiddleware.LangContextKey).(string)))
	})
	http.ListenAndServe(":3000", r)
}

Documentation

Index

• Variables
• type LangMiddleware
  • func NewCookieAndHeader(defaultLang string, supportedLanguages []string, cookieName string) (*LangMiddleware, error)
  • func NewCookieOnly(defaultLang string, supportedLanguages []string, cookieName string) (*LangMiddleware, error)
  • func NewHeaderOnly(defaultLang string, supportedLanguages []string) (*LangMiddleware, error)
  • func (i *LangMiddleware) Extractor() func(http.Handler) http.Handler
• type LangSource

Variables

var (
	// ErrHeaderParsing is returned by ParseLangHeader when accept language header is not conform
	ErrHeaderParsing = errors.New("An error occurred while parsing accept-language header")
	// ErrEmptyHeader is returned by ParseLangHeader when no tags are provided in header
	ErrEmptyHeader = errors.New("Accept-language header is empty")
)

var LangContextKey = &contextKey{"lang"}

LangContextKey is the key used to store Lang in context

Types

type LangMiddleware

type LangMiddleware struct {
	CookieName         string
	SupportedLanguages []string
	DefaultLanguage    string
	// contains filtered or unexported fields
}

LangMiddleware

func NewCookieAndHeader

func NewCookieAndHeader(defaultLang string, supportedLanguages []string, cookieName string) (*LangMiddleware, error)

NewCookieAndHeader returns a new LangMiddleware with a configuration to use informations from both cookie and accept-language header

func NewCookieOnly

func NewCookieOnly(defaultLang string, supportedLanguages []string, cookieName string) (*LangMiddleware, error)

NewCookieOnly returns a new LangMiddleware with a configuration to use only informations from cookie named

func NewHeaderOnly

func NewHeaderOnly(defaultLang string, supportedLanguages []string) (*LangMiddleware, error)

NewHeaderOnly returns a new LangMiddleware with a configuration to use only informations from accept-language header

func (*LangMiddleware) Extractor

func (i *LangMiddleware) Extractor() func(http.Handler) http.Handler

Extractor return http handler to use as middleware

type LangSource

type LangSource int

LangSource can be used to select possible source of language

const (
	// Cookie indicates that only cookie will be used to extract language informations
	Cookie LangSource = 1 << iota
	// Header indicates that only header will be used to extract language informations
	Header
	// HeaderAndCookie indicates that both header and cookie will be used to extract language informations
	HeaderAndCookie = Cookie | Header
)