gin/README.md

#Gin Web Framework [![Build Status](https://travis-ci.org/gin-gonic/gin.svg)](https://travis-ci.org/gin-gonic/gin) [![Coverage Status](https://coveralls.io/repos/gin-gonic/gin/badge.svg?branch=develop)](https://coveralls.io/r/gin-gonic/gin?branch=develop)

 [![GoDoc](https://godoc.org/github.com/gin-gonic/gin?status.svg)](https://godoc.org/github.com/gin-gonic/gin)  [![Join the chat at https://gitter.im/gin-gonic/gin](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/gin-gonic/gin?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)

Gin is a web framework written in Golang. It features a martini-like API with much better performance, up to 40 times faster thanks to [httprouter](https://github.com/julienschmidt/httprouter). If you need performance and good productivity, you will love Gin. 

![Gin console logger](https://gin-gonic.github.io/gin/other/console.png)

```
$ cat test.go
```
```go
package main

import (
	"net/http"
	"github.com/gin-gonic/gin"
)

func main() {
	router := gin.Default()
	router.GET("/", func(c *gin.Context) {
		c.String(http.StatusOK, "hello world")
	})
	router.GET("/ping", func(c *gin.Context) {
		c.String(http.StatusOK, "pong")
	})
	router.POST("/submit", func(c *gin.Context) {
		c.String(http.StatusUnauthorized, "not authorized")
	})
	router.PUT("/error", func(c *gin.Context) {
		c.String(http.StatusInternalServerError, "an error happened :(")
	})
	router.Run(":8080")
}
```

##Gin is new, will it be supported?

Yes, Gin is an internal tool of [Manu](https://github.com/manucorporat) and [Javi](https://github.com/javierprovecho) for many of our projects/start-ups. We developed it and we are going to continue using and improve it.


##Roadmap for v1.0
- [ ] Ask our designer for a cool logo
- [ ] Add tons of unit tests
- [ ] Add internal benchmarks suite
- [ ] More powerful validation API
- [ ] Improve documentation
- [ ] Add Swagger support
- [x] Stable API
- [x] Improve logging system
- [x] Improve JSON/XML validation using bindings
- [x] Improve XML support
- [x] Flexible rendering system
- [x] Add more cool middlewares, for example redis caching (this also helps developers to understand the framework).
- [x] Continuous integration
- [x] Performance improments, reduce allocation and garbage collection overhead
- [x] Fix bugs



## Start using it
Obviously, you need to have Git and Go already installed to run Gin.  
Run this in your terminal

```
go get github.com/gin-gonic/gin
```
Then import it in your Go code:

```
import "github.com/gin-gonic/gin"
```

##API Examples

#### Create most basic PING/PONG HTTP endpoint
```go 
package main

import (
	"net/http"
	"github.com/gin-gonic/gin"
)

func main() {
	r := gin.Default()
	r.GET("/ping", func(c *gin.Context) {
		c.String(http.StatusOK, "pong")
	})

	// Listen and serve on 0.0.0.0:8080
	r.Run(":8080")
}
```

#### Using GET, POST, PUT, PATCH, DELETE and OPTIONS

```go
func main() {
	// Creates a gin router + logger and recovery (crash-free) middlewares
	r := gin.Default()

	r.GET("/someGet", getting)
	r.POST("/somePost", posting)
	r.PUT("/somePut", putting)
	r.DELETE("/someDelete", deleting)
	r.PATCH("/somePatch", patching)
	r.HEAD("/someHead", head)
	r.OPTIONS("/someOptions", options)

	// Listen and server on 0.0.0.0:8080
	r.Run(":8080")
}
```

#### Parameters in path

```go
func main() {
	r := gin.Default()
	
	// This handler will match /user/john but will not match neither /user/ or /user
	r.GET("/user/:name", func(c *gin.Context) {
		name := c.Params.ByName("name")
		message := "Hello "+name
		c.String(http.StatusOK, message)
	})

	// However, this one will match /user/john/ and also /user/john/send
	// If no other routers match /user/john, it will redirect to /user/join/
	r.GET("/user/:name/*action", func(c *gin.Context) {
		name := c.Params.ByName("name")
		action := c.Params.ByName("action")
		message := name + " is " + action
		c.String(http.StatusOK, message)
	})
	
	// Listen and server on 0.0.0.0:8080
	r.Run(":8080")
}
```
###Form parameters
```go
func main() {
	r := gin.Default()
	
	// This will respond to urls like search?firstname=Jane&lastname=Doe
	r.GET("/search", func(c *gin.Context) {
		// You need to call ParseForm() on the request to receive url and form params first
		c.Request.ParseForm()
		
		firstname := c.Request.Form.Get("firstname")
		lastname := c.Request.Form.Get("lastname")

		message := "Hello "+ firstname + lastname
		c.String(http.StatusOK, message)
	})
	r.Run(":8080")
}
```

###Multipart Form
```go
package main

import (
	"github.com/gin-gonic/gin"
	"github.com/gin-gonic/gin/binding"
)

type LoginForm struct {
	User     string `form:"user" binding:"required"`
	Password string `form:"password" binding:"required"`
}

func main() {

	r := gin.Default()

	r.POST("/login", func(c *gin.Context) {

		var form LoginForm
		c.BindWith(&form, binding.MultipartForm)

		if form.User == "user" && form.Password == "password" {
			c.JSON(200, gin.H{"status": "you are logged in"})
		} else {
			c.JSON(401, gin.H{"status": "unauthorized"})
		}

	})

	r.Run(":8080")

}
```

Test it with:
```bash
$ curl -v --form user=user --form password=password http://localhost:8080/login
```

#### Grouping routes
```go
func main() {
	r := gin.Default()

	// Simple group: v1
	v1 := r.Group("/v1")
	{
		v1.POST("/login", loginEndpoint)
		v1.POST("/submit", submitEndpoint)
		v1.POST("/read", readEndpoint)
	}

	// Simple group: v2
	v2 := r.Group("/v2")
	{
		v2.POST("/login", loginEndpoint)
		v2.POST("/submit", submitEndpoint)
		v2.POST("/read", readEndpoint)
	}

	// Listen and server on 0.0.0.0:8080
	r.Run(":8080")
}
```


#### Blank Gin without middlewares by default

Use

```go
r := gin.New()
```
instead of

```go
r := gin.Default()
```


#### Using middlewares
```go
func main() {
	// Creates a router without any middleware by default
	r := gin.New()

	// Global middlewares
	r.Use(gin.Logger())
	r.Use(gin.Recovery())

	// Per route middlewares, you can add as many as you desire.
	r.GET("/benchmark", MyBenchLogger(), benchEndpoint)

	// Authorization group
	// authorized := r.Group("/", AuthRequired())
	// exactly the same than:
	authorized := r.Group("/")
	// per group middlewares! in this case we use the custom created
	// AuthRequired() middleware just in the "authorized" group.
	authorized.Use(AuthRequired())
	{
		authorized.POST("/login", loginEndpoint)
		authorized.POST("/submit", submitEndpoint)
		authorized.POST("/read", readEndpoint)

		// nested group
		testing := authorized.Group("testing")
		testing.GET("/analytics", analyticsEndpoint)
	}

	// Listen and server on 0.0.0.0:8080
	r.Run(":8080")
}
```

#### Model binding and validation

To bind a request body into a type, use model binding. We currently support binding of JSON, XML and standard form values (foo=bar&boo=baz).

Note that you need to set the corresponding binding tag on all fields you want to bind. For example, when binding from JSON, set `json:"fieldname"`.

When using the Bind-method, Gin tries to infer the binder depending on the Content-Type header. If you are sure what you are binding, you can use BindWith. 

You can also specify that specific fields are required. If a field is decorated with `binding:"required"` and has a empty value when binding, the current request will fail with an error.