Add '*' matcher for parameters

For get_type_provided:
'*' will be match any parameters of media-range in "accept" header.
If '*' matched, then '*' is replaced by the matching parameters.
If Accept header is missing and '*' using, then in media_type in parameters
will be '*' and reply content-type will be without any parameters.

For content_types_accepted:
'*' will be match any parameters in "content-type" header.

test/rest_param_all.erl

@@ -0,0 +1,36 @@
+-module(rest_param_all).
+
+-export([init/3]).
+-export([allowed_methods/2]).
+-export([content_types_provided/2]).
+-export([get_text_plain/2]).
+-export([content_types_accepted/2]).
+-export([put_text_plain/2]).
+
+init(_Transport, _Req, _Opts) ->
+	{upgrade, protocol, cowboy_rest}.
+
+allowed_methods(Req, State) ->
+	{[<<"GET">>, <<"PUT">>], Req, State}.
+
+content_types_provided(Req, State) ->
+	{[{{<<"text">>, <<"plain">>, '*'}, get_text_plain}], Req, State}.
+
+get_text_plain(Req, State) ->
+	{{_, _, Param}, Req2} =
+		cowboy_req:meta(media_type, Req, {{<<"text">>, <<"plain">>}, []}),
+	Body = if
+	Param == '*' ->
+		<<"'*'">>;
+	Param == [] ->
+		<<"[]">>;
+	Param /= [] ->
+		iolist_to_binary([[Key, $=, Value] || {Key, Value} <- Param])
+	end,
+	{Body, Req2, State}.
+
+content_types_accepted(Req, State) ->
+	{[{{<<"text">>, <<"plain">>, '*'}, put_text_plain}], Req, State}.
+
+put_text_plain(Req, State) ->
+	{true, Req, State}.