middleware

Middleware Framework For Go net/http.

Fully compatible with http.Handler. To use full featured middleware, you only need to add a no parameter next() call.

Getting Started

go get github.com/withwind8/middleware

package main

import (
  "log"
  "time"
  "net/http"
    
  "github.com/withwind8/middleware"
)

func main(){
  app := middleware.New()
  
  //a simple log middleware using func
  app.UseFunc(func(w http.ResponseWriter, r *http.Request, next func()){
    start := time.Now()
    
    next()
    
    log.Printf("%s %v",r.URL.Path,time.Since(start))
  })
  
  mux := http.NewServeMux()
  mux.HandleFunc("/",func(w http.ResponseWriter, r *http.Request) {
    w.Write([]byte("Hello World!"))
  })
  
  //can using standard http.Handler as middleware
  app.UseHandler(mux)
  
  log.Fatal(app.Listen(":8080"))
}  

API

func New()

Return a middleware container instance

method Use(middleware Middleware)

Using a Middleware interface as middleware

type Middleware interface {
	ServeHTTP(w http.ResponseWriter, r *http.Request, next func())
}

method UseFunc(middlewareFunc MiddlewareFunc)

Using a MiddlewareFunc as middleware

type MiddlewareFunc func(w http.ResponseWriter, r *http.Request, next func())

method UseHandler(handler http.Handler)

Using a http.Handler interface as middleware, next() will be executed automatically at the end

method UseHandlerFunc(handlerFunc http.HandlerFunc)

Using a http.HandlerFunc as middleware, next() will be executed automatically at the end

method Listen(addr string) error

Start the server in with given address.

app.Listen(":8080")

is Simply sugar for the following:

http.ListenAndServe(":8080", app)

Usage

Suppose you have 2 middleware (1 interface 1 func) and 2 handler (1 interface 1 func), and use them in the following order:

app.Use(middleware1)
app.UseHandler(handler1)
app.UseFunc(middleware2)
app.UseHandlerFunc(handler2)

Finally, the execution sequence is as follows：

1. middleware1_before_next
2. handler1
3. middleware2_before_next
4. handler2
5. middleware2_after_next
6. middleware1_after_next