CODEWITHSUNDEEP
google-app-enginego
John
John

Reputation: 634

Add middleware on HTTP

I have this productHandler:

func productHandler(w http.ResponseWriter, r *http.Request) {
  var prop controller.Product
  switch r.Method {
    case "GET":
      prop.All()
  } [etc..]
}

Then I register my productHandler

http.HandleFunc("/products/", productHandler)

How can I add the below middleware to HTTP request?

func Accept(next http.Handler) http.Handler { 
  fc := func(w http.ResponseWriter, r *http.Request) {
    if r.Header.Get("Accept") != "application/json" {
      w.Write([]byte("Test M."))
      return
    }
  next.ServeHTTP(w, r)
  }
  return http.HandlerFunc(fc)
 }

How can I add this middleware to all my handlers?

I have tried:

type Pr struct {
  handler http.Handler
}

func (p *Pr) ServeHttp(w http.ResponseWriter, r *http.Request) {
  a.handler.ServeHTTP(w, r)
  w.Write([]byte("Test M"))
}

I am trying to implement this on the app engine SDK.

But it din't work.

Upvotes: 0

Views: 152

Answers (1)

fabmilo
fabmilo

Reputation: 48330

Try http.Handle("/products/", Accept(http.HandlerFunc(productHandler)))

http://play.golang.org/p/mvclC4UUMV

package main

import (
    "fmt"
    "net/http"
)

func Accept(next http.Handler) http.Handler {
    fc := func(w http.ResponseWriter, r *http.Request) {
        if r.Header.Get("Accept") != "application/json" {
            w.Write([]byte("Test M."))
            return
        }
        next.ServeHTTP(w, r)
    }
    return http.HandlerFunc(fc)
}

func productHandler(w http.ResponseWriter, r *http.Request) {
    switch r.Method {
    case "GET":

    }
}

func main() {

    http.Handle("/products/", Accept(http.HandlerFunc(productHandler)))

}

Upvotes: 1

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