dvln / siesta

Composable framework for writing HTTP handlers in Go.

siesta

Siesta is a composable framework for writing HTTP handlers in Go. It supports typed URL parameters, middleware chains, and context passing.

Getting started

Siesta offers a Service type, which is a collection of middleware chains and handlers rooted at a base URI. There is no distinction between a middleware function and a handler function; they are all considered to be handlers and have access to the same arguments.

Siesta accepts many types of handlers. Refer to the GoDoc documentation for Service.Route for more information.

Here is the simple program in the examples directory. It demonstrates the use of a Service, routing, middleware, and a Context.

package main

import (
	"fmt"
	"log"
	"net/http"
	"time"

	"github.com/VividCortex/siesta"
)

func main() {
	// Create a new Service rooted at "/"
	service := siesta.NewService("/")

	// Route accepts normal http.Handlers.
	// The arguments are the method, path, description,
	// and the handler.
	service.Route("GET", "/", "Sends 'Hello, world!'",
		func(w http.ResponseWriter, r *http.Request) {
		fmt.Fprintln(w, "Hello, world!")
	})

	// Let's create some simple "middleware."
	// This handler will accept a Context argument and will add the current
	// time to it.
	timestamper := func(c siesta.Context, w http.ResponseWriter, r *http.Request) {
		c.Set("start", time.Now())
	}

	// This is the handler that will actually send data back to the client.
	// It also takes a Context argument so it can get the timestamp from the
	// previous handler.
	timeHandler := func(c siesta.Context, w http.ResponseWriter, r *http.Request) {
		start := c.Get("start").(time.Time)
		delta := time.Now().Sub(start)
		fmt.Fprintf(w, "That took %v.\n", delta)
	}

	// We can compose these handlers together.
	timeHandlers := siesta.Compose(timestamper, timeHandler)

	// Finally, we'll add the new handler we created using composition to a new route.
	service.Route("GET", "/time", "Sends how long it took to send a message", timeHandlers)

	// service is an http.Handler, so we can pass it directly to ListenAndServe.
	log.Fatal(http.ListenAndServe(":8080", service))
}

Siesta also provides utilities to manage URL parameters similar to the flag package. Refer to the params example for a demonstration.

Contributing

Contributions are welcome. Please open pull requests or issue reports!

License

Siesta is licensed under the MIT license. The router, which is adapted from httprouter is licensed separately.