Specialized middlewares

jsonhandler.go

package main

import (
	"encoding/json"
	"github.com/bmizerany/pat"
	"html/template"
	"log"
	"net/http"
)

/*
https://gist.github.com/jordic/9230724131e3ba987ec6
  Idea: Write some kind of "middlewares", especialized,
  that cats as some "kind" of generic views...
  I write, one JSONHandler... the only thing it does,
  is transform to jason the output of the "Model" or "Collection"
  But the same idea, could we done, with HtmlHandlers, that render
  some tampletes... this way I think it would be easy, to write,
  webapps ..
*/

const TPL = `
    <h1>Hello {{.Obj.Name}} is this your surname {{.Obj.Surname}}?</h1>`
const TPLC = `
    {{ range .Obj }}
        <h1>Hello {{.Name}} is this your surname {{.Surname}} ?<h1>
    {{ end }}
    `

type JSONHandler func(http.ResponseWriter, *http.Request) interface{}

func (f JSONHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	out := f(w, r)
	res, _ := json.Marshal(out)
	w.Write(res)
}

type htmlHandler struct {
	template string
	name     string
	fu       func(http.ResponseWriter, *http.Request) interface{}
}

func (h *htmlHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	out := h.fu(w, r)
	t := template.Must(template.New(h.name).Parse(h.template))
	res := map[string]interface{}{
		"Obj": out,
	}
	t.Execute(w, res)
}

func HtmlHandler(f func(http.ResponseWriter, *http.Request) interface{},
	template string, name string) http.Handler {
	return &htmlHandler{template, name, f}
}

func main() {

	m := pat.New()
	m.Get("/hello/", JSONHandler(GetClient))
	m.Get("/collection/", JSONHandler(GetClientCollection))
	m.Get("/hello.html", HtmlHandler(GetClient, TPL, "object"))
	m.Get("/collection.html", HtmlHandler(GetClientCollection, TPLC, "object2"))

	http.Handle("/", m)
	err := http.ListenAndServe(":9999", nil)
	if err != nil {
		log.Fatal("Listen and server", err)
	}

}

func GetClient(w http.ResponseWriter, r *http.Request) interface{} {
	return Name{Name: "John", Surname: "Smith"}
}

func GetClientCollection(w http.ResponseWriter, r *http.Request) interface{} {
	var a = make([]Name, 2)
	a[0] = Name{Name: "john", Surname: "Smith"}
	a[1] = Name{Name: "Paul", Surname: "Denver"}
	return a
}

type Name struct {
	Name    string
	Surname string
}