| commit | 70306a1afa454a0ee55c5c07a5481e1ec821da8f | [log] [tgz] |
|---|---|---|
| author | Justinas Stankevicius <justinas@justinas.me> | Sun May 25 12:46:00 2014 +0300 |
| committer | Justinas Stankevicius <justinas@justinas.me> | Sun May 25 12:46:00 2014 +0300 |
| tree | a5fffbe3bc514740ea8db9f1d4072033fee132cf | |
| parent | 857083b18fb9bb1c4587714bd081ffd286acadab [diff] |
So bad at this.
Alice provides a convenient way to chain your HTTP middleware functions and the app handler.
In short, it transforms Middleware1(Middleware2(Middleware3(App))) to alice.New(Middleware1, Middleware, Middleware3).Then(App).
None of the other middleware chaining solutions behaves exactly like Alice. Alice is as minimal as a chaining solution gets. In its essence, it's just a for loop that does the wrapping for you.
Your middleware constructors should have the form of
func (http.Handler) http.Handler
Some middleware provide this out of the box. For ones that don‘t, it’s trivial to write one yourself.
func myStripPrefix(h http.Handler) http.Handler {
return http.StripPrefix("/old", h)
}
This complete example shows the full power of Alice.
package main
import (
"net/http"
"time"
"github.com/PuerkitoBio/throttled"
"github.com/justinas/alice"
"github.com/justinas/nosurf"
)
func timeoutHandler(h http.Handler) http.Handler {
return http.TimeoutHandler(h, 1*time.Second, "timed out")
}
func myApp(w http.ResponseWriter, r *http.Request) {
w.Write([]byte("Hello world!"))
}
func main() {
th := throttled.Interval(throttled.PerSec(10), 1, &throttled.VaryBy{Path: true}, 50)
myHandler := http.HandlerFunc(myApp)
chain := alice.New(th.Throttle, timeoutHandler, nosurf.NewPure).Then(myHandler)
http.ListenAndServe(":8000", chain)
}
Here, the request will pass throttled first then an http.TimeoutHandler we've set up, then nosurf and will finally reach our handler.
Note that Alice makes no guarantees for how one or another piece of middleware will behave. It does not execute all handlers sequentially but wraps them in one another.
If a piece of middleware were to stop the chain, the request will not reach the inner handlers. This is intentional behavior.
develop branch, commit, test.