https://github.com/tiancaiamao/middleware

the missing golang middleware!
https://github.com/tiancaiamao/middleware

Last synced: about 1 month ago
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the missing golang middleware!

• Host: GitHub
• URL: https://github.com/tiancaiamao/middleware
• Owner: tiancaiamao
• Created: 2015-05-11T07:23:33.000Z (over 9 years ago)
• Default Branch: master
• Last Pushed: 2016-03-11T02:45:50.000Z (over 8 years ago)
• Last Synced: 2023-03-27T22:23:03.981Z (over 1 year ago)
• Language: Go
• Size: 5.86 KB
• Stars: 6
• Watchers: 3
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
API in [godoc](http://godoc.org/github.com/tiancaiamao/middleware)

The trick played here is that context is hiden in ResponseWriter. So, one can write standard http.Handler as usual

and get the context as need, in this way:

	func HelloWorld(w http.ResponseWriter, r *http.Request) {

		if cw, ok := w.(middleware.ContextResponseWriter); ok {

			value := cw.Value("key")

			...

		}

	}

As elegancy as gorilla while global lock is unnecessary. 

A complete demo:

	package main

	

	import (

		"github.com/tiancaiamao/middleware"

		"io"

		"net/http"

	)

	

	type MyContextResponseWriter struct {

		http.ResponseWriter

		key, value interface{}

	}

	

	func (w *MyContextResponseWriter) Value(key interface{}) interface{} {

		if w.key == key {

			return w.value

		}

		return nil

	}

	

	func HelloWorld(w http.ResponseWriter, r *http.Request) {

		if ctx, ok := w.(middleware.ContextResponseWriter); ok {

			valueFromContext := ctx.Value("xxx")

			io.WriteString(w, "hello, "+valueFromContext.(string))

			return

		}

		

		io.WriteString(w, "hello world")

	}

	

	type MiddleWareDemo struct{}

	

	func (demo MiddleWareDemo) Chain(h http.Handler) http.Handler {

		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {

			cw := &MyContextResponseWriter{

				ResponseWriter: w,

				key:            "xxx",

				value:          "demo",

			}

			

			h.ServeHTTP(cw, r)

		})

	}

	

	func main() {

		handler := middleware.New(http.HandlerFunc(HelloWorld), MiddleWareDemo{})

		http.ListenAndServe(":8080", handler)

	}

Tips: 

1. golang/x/net/context can be used as ContextResponseWriter's Value if you want. 

2. the code is deadly simple, so you may copy one in your project rather then import this package.