Merge pull request #101 from turtleDeng/master

trails_handler supports parameter

README.md

@@ -101,11 +101,11 @@ Dispatch = cowboy_router:compile(Routes),
 ```
 
 But now with `trails` you're able to define the routes on each resource handler.
-The handler must implement the callback `trails/0` and return the specific
+The handler must implement the callback `trails/0` or `trails/1` and return the specific
 routes for that handler. For a better understanding, you can check out the
 examples in the `test` folder ([trails_test_handler](./test/trails_test_handler.erl)).
 
-Once you have implemented the `trails/0` callback on your handlers, you can do
+Once you have implemented the `trails/0` or `trails/1` callback on your handlers, you can do
 something like this:
 
 ```erlang
@@ -116,6 +116,7 @@ Handlers =
   , spts_serpents_handler
   , spts_single_serpent_handler
   , spts_news_handler
+  , {support_params_handler, #{key => value}}
   ],
 Trails =
   [ {"/", cowboy_static, {file, "www/index.html"}}

src/trails_handler.erl

@@ -8,6 +8,9 @@
 
 %% @doc Returns the cowboy routes defined in the called module.
 -callback trails() -> trails:trails().
+-callback trails(Opts :: map()) -> trails:trails().
+-optional_callbacks([trails/0, trails/1]).
 
--spec trails(module()) -> trails:trails().
+-spec trails(module() | {module(), map()}) -> trails:trails().
+trails({Module, Opts}) -> Module:trails(Opts);
 trails(Module) -> Module:trails().

test/trails_SUITE.erl

@@ -312,14 +312,21 @@ basic_trails_routes(_Config) ->
     , {"/api/resource1/[:id]", trails_test_handler, []}
     , {"/api/:id/resource2", trails_test_handler, [arg0]}
     ],
+  ExpectedResponse4 =
+    [ {"/api/resource5/[:id]", trails_test3_handler, []}
+    , {"/api/:id/resource6", trails_test3_handler, [#{test_key => test_value}]}
+    ] ++ ExpectedResponse3,
   Handlers1 = [trails_test_handler, trails_test2_handler],
   Handlers2 = [trails_test2_handler, trails_test_handler],
+  Handlers3 = [{trails_test3_handler, #{test_key => test_value}}],
   Trails1 = StaticRoutes ++ trails:trails(Handlers1),
   ExpectedResponse1 = Trails1,
   Trails2 = StaticRoutes ++ trails:trails(trails_test_handler),
   ExpectedResponse2 = Trails2,
   Trails3 = StaticRoutes ++ trails:trails(Handlers2),
   ExpectedResponse3 = Trails3,
+  Trails4 = trails:trails(Handlers3) ++ Trails3,
+  ExpectedResponse4 = Trails4,
   {comment, ""}.
 
 -spec trails_store(config()) -> {atom(), string()}.

test/trails_test3_handler.erl

@@ -0,0 +1,12 @@
+-module(trails_test3_handler).
+
+-behaviour(trails_handler).
+
+%% API
+-export([trails/1]).
+
+trails(Opts) ->
+  [
+   {"/api/resource5/[:id]", trails_test3_handler, []},
+   {"/api/:id/resource6", trails_test3_handler, [Opts]}
+  ].