Fresh is a Sinatra inspired Erlang web framework based on Mochiweb that supports registering multiple "web handlers" that are dispatched to when you access a Fresh instance. This allows you to theoretically serve sections of your website from multiple physically separate computers. For instance, your main pages could serve from a server in Hong Kong while your user pages are served from Marfa, TX.
-module(example_web_handler).
-behaviour(fresh_handler).
-export([dispatch_rules/0, 'GET'/2]).
dispatch_rules() ->
fun('GET', ["fresh"], _Req) -> true;
('POST', ["fresh"], _Req) -> true;
(_, _, _) -> false end.
'GET'(["fresh"], _Req) ->
"So fresh!".
'POST'(["fresh"], Req) ->
Body = Req:recv_body(),
{json, [{ok, Body}]}.
-module(example).
-behaviour(application).
-behaviour(supervisor).
-export([start/0, stop/0]).
-export([init/1, start/2, stop/1]).
start() -> application:start(?MODULE).
stop() -> application:stop(?MODULE).
start(_Type, _Args) ->
supervisor:start_link({local, example_sup}, ?MODULE, []).
stop(_State) -> ok.
init([]) ->
WebHandler = {example_web_handler,
{fresh_handler, start_link, [example_web_handler]},
permanent, 5000, worker, [fresh_handler]},
{ok, {{one_for_one, 10, 10}, [WebHandler]}}.
{application, example, [
{description, "A Fresh example app"},
{vsn, "0.1"},
{applications, [kernel, stdlib, sasl]},
{modules, [example, example_web_handler]},
{registered, [example]},
{mod, {example, []}}
]}.
port: port number, default: 7235
- Allow custom error handlers (easy)
- Register new dispatch rules during hot OTP upgrade (harder)
- Statically analyze handler AST during registration to create preliminary dispatch rules (hardest)