Add an example with custom middleware

examples/markdown_middleware/src/markdown_converter.erl

@@ -0,0 +1,29 @@
+%% Feel free to use, reuse and abuse the code in this file.
+
+-module(markdown_converter).
+-behaviour(cowboy_middleware).
+
+-export([execute/2]).
+
+execute(Req, Env) ->
+	{[Path], Req1} = cowboy_req:path_info(Req),
+	case filename:extension(Path) of
+		<<".html">> -> maybe_generate_markdown(resource_path(Path));
+		_Ext -> ok
+	end,
+	{ok, Req1, Env}.
+
+maybe_generate_markdown(Path) ->
+	ModifiedAt = filelib:last_modified(source_path(Path)),
+	GeneratedAt = filelib:last_modified(Path),
+	case ModifiedAt > GeneratedAt of
+		true -> erlmarkdown:conv_file(source_path(Path), Path);
+		false -> ok
+	end.
+
+resource_path(Path) ->
+	{ok, Cwd} = file:get_cwd(),
+	filename:join([Cwd, "priv", Path]).
+
+source_path(Path) ->
+	<< (filename:rootname(Path))/binary, ".md" >>.

examples/markdown_middleware/src/markdown_middleware.app.src

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+%% Feel free to use, reuse and abuse the code in this file.
+
+{application, markdown_middleware, [
+	{description, "Cowboy static file handler example with middleware component."},
+	{vsn, "1"},
+	{modules, []},
+	{registered, []},
+	{applications, [
+		kernel,
+		stdlib,
+		cowboy
+	]},
+	{mod, {markdown_middleware_app, []}},
+	{env, []}
+]}.

examples/markdown_middleware/src/markdown_middleware.erl

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+%% Feel free to use, reuse and abuse the code in this file.
+
+-module(markdown_middleware).
+
+%% API.
+-export([start/0]).
+
+%% API.
+
+start() ->
+	ok = application:start(crypto),
+	ok = application:start(ranch),
+	ok = application:start(cowboy),
+	ok = application:start(markdown_middleware).

examples/markdown_middleware/src/markdown_middleware_app.erl

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+%% Feel free to use, reuse and abuse the code in this file.
+
+%% @private
+-module(markdown_middleware_app).
+-behaviour(application).
+
+%% API.
+-export([start/2]).
+-export([stop/1]).
+
+%% API.
+
+start(_Type, _Args) ->
+	Dispatch = cowboy_router:compile([
+		{'_', [
+			{"/[...]", cowboy_static, [
+				{directory, {priv_dir, markdown_middleware, []}},
+				{mimetypes, {fun mimetypes:path_to_mimes/2, default}}
+			]}
+		]}
+	]),
+	{ok, _} = cowboy:start_http(http, 100, [{port, 8080}], [
+		{env, [{dispatch, Dispatch}]},
+		{middlewares, [cowboy_router, markdown_converter, cowboy_handler]}
+	]),
+	markdown_middleware_sup:start_link().
+
+stop(_State) ->
+	ok.

examples/markdown_middleware/src/markdown_middleware_sup.erl

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+%% Feel free to use, reuse and abuse the code in this file.
+
+%% @private
+-module(markdown_middleware_sup).
+-behaviour(supervisor).
+
+%% API.
+-export([start_link/0]).
+
+%% supervisor.
+-export([init/1]).
+
+%% API.
+
+-spec start_link() -> {ok, pid()}.
+start_link() ->
+	supervisor:start_link({local, ?MODULE}, ?MODULE, []).
+
+%% supervisor.
+
+init([]) ->
+	Procs = [],
+	{ok, {{one_for_one, 10, 10}, Procs}}.