| # Alice |
| |
| `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)`. |
| |
| ### Why? |
| |
| 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. |
| |
| ### Usage |
| |
| 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. |
| |
| ```go |
| func myStripPrefix(h http.Handler) http.Handler { |
| return http.StripPrefix("/old", h) |
| } |
| ``` |
| |
| This complete example shows the full power of Alice. |
| |
| ```go |
| 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](https://github.com/PuerkitoBio/throttled) first, |
| then an http.TimeoutHandler we've set up, |
| then [nosurf](https://github.com/justinas/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. |
| |
| ### Contributing |
| |
| 0. Find an issue that bugs you / open a new one. |
| 1. Discuss. |
| 2. Branch off the `develop` branch, commit, test. |
| 3. Make a pull request / attach the commits to the issue. |