echo/README.md

# Echo [![GoDoc](http://img.shields.io/badge/go-documentation-blue.svg?style=flat-square)](http://godoc.org/github.com/labstack/echo) [![Build Status](http://img.shields.io/travis/labstack/echo.svg?style=flat-square)](https://travis-ci.org/labstack/echo) [![Coverage Status](http://img.shields.io/coveralls/labstack/echo.svg?style=flat-square)](https://coveralls.io/r/labstack/echo)
Echo is a fast HTTP router (zero memory allocation) + micro web framework in Go.

### Features
- Fast :rocket: router which smartly resolves conflicting routes
- Extensible middleware/handler, supports:
	- Middleware
		- `func(*echo.Context)`
		- `func(echo.HandlerFunc) echo.HandlerFunc`
		- `func(http.Handler) http.Handler`
		- `http.Handler`
		- `http.HandlerFunc`
		- `func(http.ResponseWriter, *http.Request)`
	- Handler
		- `func(*echo.Context)`
		- `http.Handler`
		- `http.HandlerFunc`
		- `func(http.ResponseWriter, *http.Request)`
- Group routing
- Handy encoding/decoding functions.
- Serve static files, including index.

### Installation
```go get github.com/labstack/echo```

### Usage
[labstack/echo/example](https://github.com/labstack/echo/tree/master/example)

```go
package main

import (
	"io"
	"net/http"

	"html/template"

	"github.com/labstack/echo"
	mw "github.com/labstack/echo/middleware"
	"github.com/rs/cors"
	"github.com/thoas/stats"
)

type (
	// Template provides HTML template rendering
	Template struct {
		templates *template.Template
	}

	user struct {
		ID   string `json:"id"`
		Name string `json:"name"`
	}
)

var (
	users map[string]user
)

// Render HTML
func (t *Template) Render(w io.Writer, name string, data interface{}) error {
	return t.templates.ExecuteTemplate(w, name, data)
}

func welcome(c *echo.Context) {
	c.Render("welcome", "Joe")
}

func createUser(c *echo.Context) {
	u := new(user)
	if err := c.Bind(u); err == nil {
		users[u.ID] = *u
		if err := c.JSON(http.StatusCreated, u); err == nil {
			// Do something!
		}
		return
	}
	http.Error(c.Response, http.StatusText(http.StatusBadRequest), http.StatusBadRequest)
}

func getUsers(c *echo.Context) {
	c.JSON(http.StatusOK, users)
}

func getUser(c *echo.Context) {
	c.JSON(http.StatusOK, users[c.P(0)])
}

func main() {
	e := echo.New()

	//*************************//
	//   Built-in middleware   //
	//*************************//
	e.Use(mw.Logger)

	//****************************//
	//   Third-party middleware   //
	//****************************//
	// https://github.com/rs/cors
	e.Use(cors.Default().Handler)

	// https://github.com/thoas/stats
	s := stats.New()
	e.Use(s.Handler)
	// Route
	e.Get("/stats", func(c *echo.Context) {
		c.JSON(200, s.Data())
	})

	// Serve index file
	e.Index("public/index.html")

	// Serve static files
	e.Static("/js", "public/js")

	//************//
	//   Routes   //
	//************//
	e.Post("/users", createUser)
	e.Get("/users", getUsers)
	e.Get("/users/:id", getUser)

	//***************//
	//   Templates   //
	//***************//
	t := &Template{
		// Cached templates
		templates: template.Must(template.ParseFiles("public/tpl/welcome.tpl")),
	}
	e.Renderer(t)
	e.Get("/welcome", welcome)

	//***********//
	//   Group   //
	//***********//
	// Group with parent middleware
	a := e.Group("/admin")
	a.Use(func(c *echo.Context) {
		// Security middleware
	})
	a.Get("", func(c *echo.Context) {
		c.String(http.StatusOK, "Welcome admin!")
	})

	// Group with no parent middleware
	g := e.Group("/files", func(c *echo.Context) {
		// Security middleware
	})
	g.Get("", func(c *echo.Context) {
		c.String(http.StatusOK, "Your files!")
	})

	// Start server
	e.Run(":8080")
}

func init() {
	users = map[string]user{
		"1": user{
			ID:   "1",
			Name: "Wreck-It Ralph",
		},
	}
}
```

### Benchmark
Based on [julienschmidt/go-http-routing-benchmark] (https://github.com/vishr/go-http-routing-benchmark), April 1, 2015
##### [GitHub API](http://developer.github.com/v3)
> Echo: 42728 ns/op, 0 B/op, 0 allocs/op

```
BenchmarkAce_GithubAll	   	   20000	     65328 ns/op	   13792 B/op	     167 allocs/op
BenchmarkBear_GithubAll	   	   10000	    241852 ns/op	   79952 B/op	     943 allocs/op
BenchmarkBeego_GithubAll	    3000	    458234 ns/op	  146272 B/op	    2092 allocs/op
BenchmarkBone_GithubAll	    	1000	   1923508 ns/op	  648016 B/op	    8119 allocs/op
BenchmarkDenco_GithubAll	   20000	     81294 ns/op	   20224 B/op	     167 allocs/op
BenchmarkEcho_GithubAll	   	   30000	     42728 ns/op	       0 B/op	       0 allocs/op
BenchmarkGin_GithubAll	   	   20000	     69373 ns/op	   13792 B/op	     167 allocs/op
BenchmarkGocraftWeb_GithubAll  10000	    370978 ns/op	  133280 B/op	    1889 allocs/op
BenchmarkGoji_GithubAll	    	3000	    542766 ns/op	   56113 B/op	     334 allocs/op
BenchmarkGoJsonRest_GithubAll	5000	    452551 ns/op	  135995 B/op	    2940 allocs/op
BenchmarkGoRestful_GithubAll	 200	   9500204 ns/op	  707604 B/op	    7558 allocs/op
BenchmarkGorillaMux_GithubAll	 200	   6770545 ns/op	  153137 B/op	    1791 allocs/op
BenchmarkHttpRouter_GithubAll  30000	     56097 ns/op	   13792 B/op	     167 allocs/op
BenchmarkHttpTreeMux_GithubAll 10000	    143175 ns/op	   56112 B/op	     334 allocs/op
BenchmarkKocha_GithubAll	   10000	    147959 ns/op	   23304 B/op	     843 allocs/op
BenchmarkMacaron_GithubAll	    2000	    724650 ns/op	  224960 B/op	    2315 allocs/op
BenchmarkMartini_GithubAll	     100	  10926021 ns/op	  237953 B/op	    2686 allocs/op
BenchmarkPat_GithubAll	     	 300	   4525114 ns/op	 1504101 B/op	   32222 allocs/op
BenchmarkRevel_GithubAll	    2000	   1172963 ns/op	  345553 B/op	    5918 allocs/op
BenchmarkRivet_GithubAll	   10000	    249104 ns/op	   84272 B/op	    1079 allocs/op
BenchmarkTango_GithubAll	     300	   4012826 ns/op	 1368581 B/op	   29157 allocs/op
BenchmarkTigerTonic_GithubAll	2000	    975450 ns/op	  241088 B/op	    6052 allocs/op
BenchmarkTraffic_GithubAll	     200	   7540377 ns/op	 2664762 B/op	   22390 allocs/op
BenchmarkVulcan_GithubAll	    5000	    307241 ns/op	   19894 B/op	     609 allocs/op
BenchmarkZeus_GithubAll	        2000	    752907 ns/op	  300688 B/op	    2648 allocs/op
```