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-rw-r--r--guide/routing.md5
-rw-r--r--src/cowboy_router.erl64
2 files changed, 59 insertions, 10 deletions
diff --git a/guide/routing.md b/guide/routing.md
index 2afb2f0..659b27d 100644
--- a/guide/routing.md
+++ b/guide/routing.md
@@ -196,8 +196,9 @@ Constraints
-----------
After the matching has completed, the resulting bindings can be tested
-against a set of constraints. The match will succeed only if they all
-succeed.
+against a set of constraints. Constraints are only tested when the
+binding is defined. They run in the order you defined them. The match
+will succeed only if they all succeed.
They are always given as a two or three elements tuple, where the first
element is the name of the binding, the second element is the constraint's
diff --git a/src/cowboy_router.erl b/src/cowboy_router.erl
index 376ff4f..7096bd3 100644
--- a/src/cowboy_router.erl
+++ b/src/cowboy_router.erl
@@ -33,7 +33,7 @@
-export_type([bindings/0]).
-export_type([tokens/0]).
--type constraints() :: [].
+-type constraints() :: [{atom(), int}].
-export_type([constraints/0]).
-type route_match() :: binary() | string().
@@ -222,16 +222,22 @@ match([], _, _) ->
%% If the host is '_' then there can be no constraints.
match([{'_', [], PathMatchs}|_Tail], _, Path) ->
match_path(PathMatchs, undefined, Path, []);
-match([{HostMatch, _Constraints, PathMatchs}|Tail], Tokens, Path)
+match([{HostMatch, Constraints, PathMatchs}|Tail], Tokens, Path)
when is_list(Tokens) ->
case list_match(Tokens, HostMatch, []) of
false ->
match(Tail, Tokens, Path);
- {true, Bindings, undefined} ->
- match_path(PathMatchs, undefined, Path, Bindings);
{true, Bindings, HostInfo} ->
- match_path(PathMatchs, lists:reverse(HostInfo),
- Path, Bindings)
+ HostInfo2 = case HostInfo of
+ undefined -> undefined;
+ _ -> lists:reverse(HostInfo)
+ end,
+ case check_constraints(Constraints, Bindings) of
+ {ok, Bindings2} ->
+ match_path(PathMatchs, HostInfo2, Path, Bindings2);
+ nomatch ->
+ match(Tail, Tokens, Path)
+ end
end;
match(Dispatch, Host, Path) ->
match(Dispatch, split_host(Host), Path).
@@ -249,19 +255,50 @@ match_path([{'_', [], Handler, Opts}|_Tail], HostInfo, _, Bindings) ->
{ok, Handler, Opts, Bindings, HostInfo, undefined};
match_path([{<<"*">>, _Constraints, Handler, Opts}|_Tail], HostInfo, <<"*">>, Bindings) ->
{ok, Handler, Opts, Bindings, HostInfo, undefined};
-match_path([{PathMatch, _Constraints, Handler, Opts}|Tail], HostInfo, Tokens,
+match_path([{PathMatch, Constraints, Handler, Opts}|Tail], HostInfo, Tokens,
Bindings) when is_list(Tokens) ->
case list_match(Tokens, PathMatch, []) of
false ->
match_path(Tail, HostInfo, Tokens, Bindings);
{true, PathBinds, PathInfo} ->
- {ok, Handler, Opts, Bindings ++ PathBinds, HostInfo, PathInfo}
+ case check_constraints(Constraints, PathBinds) of
+ {ok, PathBinds2} ->
+ {ok, Handler, Opts, Bindings ++ PathBinds2,
+ HostInfo, PathInfo};
+ nomatch ->
+ match_path(Tail, HostInfo, Tokens, Bindings)
+ end
end;
match_path(_Dispatch, _HostInfo, badrequest, _Bindings) ->
{error, badrequest, path};
match_path(Dispatch, HostInfo, Path, Bindings) ->
match_path(Dispatch, HostInfo, split_path(Path), Bindings).
+check_constraints([], Bindings) ->
+ {ok, Bindings};
+check_constraints([Constraint|Tail], Bindings) ->
+ Name = element(1, Constraint),
+ case lists:keyfind(Name, 1, Bindings) of
+ false ->
+ check_constraints(Tail, Bindings);
+ {_, Value} ->
+ case check_constraint(Constraint, Value) of
+ true ->
+ check_constraints(Tail, Bindings);
+ {true, Value2} ->
+ Bindings2 = lists:keyreplace(Name, 1, Bindings,
+ {Name, Value2}),
+ check_constraints(Tail, Bindings2);
+ false ->
+ nomatch
+ end
+ end.
+
+check_constraint({_, int}, Value) ->
+ try {true, list_to_integer(binary_to_list(Value))}
+ catch _:_ -> false
+ end.
+
%% @doc Split a hostname into a list of tokens.
-spec split_host(binary()) -> tokens().
split_host(Host) ->
@@ -478,4 +515,15 @@ match_info_test_() ->
R = match(Dispatch, H, P)
end} || {H, P, R} <- Tests].
+match_constraints_test() ->
+ Dispatch = [{'_', [],
+ [{[<<"path">>, value], [{value, int}], match, []}]}],
+ {ok, _, [], [{value, 123}], _, _} = match(Dispatch,
+ <<"ninenines.eu">>, <<"/path/123">>),
+ {ok, _, [], [{value, 123}], _, _} = match(Dispatch,
+ <<"ninenines.eu">>, <<"/path/123/">>),
+ {error, notfound, path} = match(Dispatch,
+ <<"ninenines.eu">>, <<"/path/NaN/">>),
+ ok.
+
-endif.