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" >>.