go-playground/lars

package main

import (
	"fmt"
	"net/http"

	"github.com/go-playground/lars"
	mw "github.com/go-playground/lars/_examples/middleware/logging-recovery"
)

func main() {
	l := lars.New()
	// LoggingAndRecovery is just an example copy paste and modify to your needs
	l.Use(mw.LoggingAndRecovery)

	l.Get("/", HelloWorld)

	http.ListenAndServe(":3007", l.Serve())
}

// HelloWorld ...
func HelloWorld(c lars.Context) {
	c.Response().Write([]byte("Hello World"))

	// this will also work, Response() complies with http.ResponseWriter interface
	fmt.Fprint(c.Response(), "Hello World")
}

l := l.New()

// the matching param will be stored in the Context's params with name "id"
l.Get("/user/:id", UserHandler)

// serve css, js etc.. c.Param(lars.WildcardParam) will return the remaining path if 
// you need to use it in a custom handler...
l.Get("/static/*", http.StripPrefix("/static/", http.FileServer(http.Dir("static")))) 

...

l.Use(LoggingAndRecovery)
...
l.Post("/users/add", ...)

// creates a group for user + inherits all middleware registered using l.Use()
user := l.Group("/user/:userid")
user.Get("", ...)
user.Post("", ...)
user.Delete("/delete", ...)

contactInfo := user.Group("/contact-info/:ciid")
contactinfo.Delete("/delete", ...)

// creates a group for others + inherits all middleware registered using l.Use() + adds 
// OtherHandler to middleware
others := l.GroupWithMore("/others", OtherHandler)

// creates a group for admin WITH NO MIDDLEWARE... more can be added using admin.Use()
admin := l.GroupWithNone("/admin")
admin.Use(SomeAdminSecurityMiddleware)
...

...
// MyContext is a custom context
type MyContext struct {
	*lars.Ctx  // a little dash of Duck Typing....
}

// CustomContextFunction is a function that is specific to your applications needs that you added
func (mc *MyContext) CustomContextFunction() {
	// do something
}

// newContext is the function that creates your custom context +
// contains lars's default context
func newContext(l *lars.LARS) lars.Context {
	return &MyContext{
		Ctx:        lars.NewContext(l),
	}
}

// casts custom context and calls you custom handler so you don;t have to type cast lars.Context everywhere
func castCustomContext(c lars.Context, handler lars.Handler) {
	// could do it in all one statement, but in long form for readability
	h := handler.(func(*MyContext))
	ctx := c.(*MyContext)

	h(ctx)
}

func main() {
	l := lars.New()
	l.RegisterContext(newContext) // all gets cached in pools for you
	l.RegisterCustomHandler(func(*MyContext) {}, castCustomContext)
	l.Use(Logger)

	l.Get("/", Home)

	http.ListenAndServe(":3007", l.Serve())
}

// Home ...notice the receiver is *MyContext, castCustomContext handled the type casting for us
// quite the time saver if you ask me.
func Home(c *MyContext) {
	c.CustomContextFunction()
	...
}

	// first argument denotes yes or no I would like URL query parameter fields
	// to be included. i.e. 'id' in route '/user/:id' should it be included.
	// run, then change to false and you'll see user.ID is not populated.
	if err := c.Decode(true, maxBytes, &user); err != nil {
		log.Println(err)
	}

...
// can register multiple handlers, the last is considered the last in the chain and others 
// considered middleware, but just for this route and not added to middleware like l.Use() does.
l.Get(/"home", AdditionalHandler, HomeHandler)

// set custom 404 ( not Found ) handler
l.Register404(404Handler)

// Redirect to or from ending slash if route not found, default is true
l.SetRedirectTrailingSlash(true)

// Handle 405 ( Method Not allowed ), default is false
l.SetHandle405MethodNotAllowed(false)

// automatically handle OPTION requests; manually configured
// OPTION handlers take precedence. default true
l.SetAutomaticallyHandleOPTIONS(set bool)

// register custom context
l.RegisterContext(ContextFunc)

// Register custom handler type, see https://github.com/go-playground/lars/blob/master/util.go#L62
// for example handler creation
l.RegisterCustomHandler(interface{}, CustomHandlerFunc)

// NativeChainHandler is used as a helper to create your own custom handlers, or use custom handlers 
// that already exist an example usage can be found here 
// https://github.com/go-playground/lars/blob/master/util.go#L86, below is an example using nosurf CSRF middleware

l.Use(nosurf.NewPure(lars.NativeChainHandler))


// Context has 2 methods of which you should be aware of ParseForm and ParseMulipartForm, they just call the 
// default http functions but provide one more additional feature, they copy the URL params to the request 
// Forms variables, just like Query parameters would have been.
// The functions are for convenience and are totally optional.

// because 'r' is a copy of a pointer to allow the information to get
// back to the caller, need to set the value of 'r' as below with '*r'
func(w http.ResponseWriter, r *http.Request) {
	*r = *r.WithContext(context.WithValue(r.Context(), 0, "testval1"))
}

go test -bench=. -benchmem=true
#GithubAPI Routes: 203
   LARS: 49032 Bytes

#GPlusAPI Routes: 13
   LARS: 3640 Bytes

#ParseAPI Routes: 26
   LARS: 6632 Bytes

#Static Routes: 157
   LARS: 30120 Bytes

goos: darwin
goarch: amd64
pkg: github.com/joeybloggs/go-http-routing-benchmark
BenchmarkLARS_Param        	20000000	        51.6 ns/op	       0 B/op	       0 allocs/op
BenchmarkLARS_Param5       	20000000	        85.7 ns/op	       0 B/op	       0 allocs/op
BenchmarkLARS_Param20      	10000000	       215 ns/op	       0 B/op	       0 allocs/op
BenchmarkLARS_ParamWrite   	20000000	        94.3 ns/op	       0 B/op	       0 allocs/op
BenchmarkLARS_GithubStatic 	20000000	        68.7 ns/op	       0 B/op	       0 allocs/op
BenchmarkLARS_GithubParam  	20000000	       103 ns/op	       0 B/op	       0 allocs/op
BenchmarkLARS_GithubAll    	  100000	     21066 ns/op	       0 B/op	       0 allocs/op
BenchmarkLARS_GPlusStatic  	30000000	        53.1 ns/op	       0 B/op	       0 allocs/op
BenchmarkLARS_GPlusParam   	20000000	        70.3 ns/op	       0 B/op	       0 allocs/op
BenchmarkLARS_GPlus2Params 	20000000	        84.4 ns/op	       0 B/op	       0 allocs/op
BenchmarkLARS_GPlusAll     	 2000000	       894 ns/op	       0 B/op	       0 allocs/op
BenchmarkLARS_ParseStatic  	20000000	        53.5 ns/op	       0 B/op	       0 allocs/op
BenchmarkLARS_ParseParam   	20000000	        60.4 ns/op	       0 B/op	       0 allocs/op
BenchmarkLARS_Parse2Params 	20000000	        68.7 ns/op	       0 B/op	       0 allocs/op
BenchmarkLARS_ParseAll     	 1000000	      1602 ns/op	       0 B/op	       0 allocs/op
BenchmarkLARS_StaticAll    	  100000	     13777 ns/op	       0 B/op	       0 allocs/op