cowboy rest example

gistfile1.erl

%% @private
-spec init(list()) -> {ok, {SupFlags::any(), [ChildSpec::any()]}} |
                       ignore | {error, Reason::any()}.
init([]) ->
    Dispatch = [
                %% {Host, list({Path, Handler, Opts})}
                {'_', [{[<<"graphs">>, graph], kw_handler, []}]}
               ],

    RestartStrategy = one_for_one,
    MaxRestarts = 1000,
    MaxSecondsBetweenRestarts = 3600,

    SupFlags = {RestartStrategy, MaxRestarts, MaxSecondsBetweenRestarts},

    Restart = permanent,
    Shutdown = 2000,
    Type = worker,

    AChild = {cowboy, {cowboy, start_listener, [http, 100, cowboy_tcp_transport
, [{port, 8080}], cowboy_http_protocol, [{dispatch, Dispatch}]]},
              Restart, Shutdown, Type, [cowboy]},

    {ok, {SupFlags, [AChild]}}.


-module(kw_handler).

-export([init/3,
         allowed_methods/2,
         content_types_accepted/2,
         content_types_provided/2,
         get_json/2,
         put_json/2]).

init(_Transport, _Req, _Opts) ->
	{upgrade, protocol, cowboy_http_rest}.

allowed_methods(Req, State) ->
    {['HEAD', 'GET', 'POST', 'PUT'], Req, State}.

content_types_accepted(Req, State) ->
	{[{{<<"application">>, <<"json">>, []}, put_json}], Req, State}.

content_types_provided(Req, State) ->
	{[{{<<"application">>, <<"json">>, []}, get_json}], Req, State}.

put_json(Req, State) ->
    {ok, Body, Req1} = cowboy_http_req:body(Req),
    {Series, Req2} = cowboy_http_req:binding(graph, Req1),
    kc_main:add(Series, jiffy:decode(Body)),
    {true, Req2, State}.

get_json(Req, State) ->
    {Series, Req1} = cowboy_http_req:binding(graph, Req),
	{jiffy:encode(kc_main:get(Series)), Req1, State}.

They now take binary not atoms

so

allowed_methods(Req, State) ->
{[<<"HEAD">>, <<"GET">>, <<"POST">>], Req, State}.