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Catch exceptions, better error handling. Added 400 support.
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@mworrell
mworrell committed Jan 5, 2012
1 parent 3874a6a commit b1320d3
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Showing 3 changed files with 138 additions and 119 deletions.
249 changes: 132 additions & 117 deletions src/webmachine_decision_core.erl
View file
Original file line number Diff line number Diff line change
Expand Up @@ -30,26 +30,25 @@ handle_request(Resource, ReqData) ->
try
d(v3b13, Resource, ReqData)
catch
error:X ->
?WM_DBG(X),
error_response(erlang:get_stacktrace(), Resource, ReqData)
error:Error ->
error_response({Error, erlang:get_stacktrace()}, Resource, ReqData)
end.

%% @doc Call the resource or a default.
%% @spec resource_call(atom(), Resource, ReqData) -> {term(), NewResource, NewReqData}
resource_call(Fun, Rs, Rd) ->
case cacheable(Fun) of
true ->
case proplists:lookup(Fun, Rd#wm_reqdata.cache) of
none ->
{T, Rs1, Rd1} = Rs:do(Fun, Rd),
{T, Rs1, Rd1#wm_reqdata{cache=[{Fun,T}|Rd1#wm_reqdata.cache]}};
{Fun, Cached} ->
{Cached, Rs, Rd}
end;
false ->
Rs:do(Fun, Rd)
end.
case cacheable(Fun) of
true ->
case proplists:lookup(Fun, Rd#wm_reqdata.cache) of
none ->
{T, Rs1, Rd1} = Rs:do(Fun, Rd),
{T, Rs1, Rd1#wm_reqdata{cache=[{Fun,T}|Rd1#wm_reqdata.cache]}};
{Fun, Cached} ->
{Cached, Rs, Rd}
end;
false ->
Rs:do(Fun, Rd)
end.

cacheable(charsets_provided) -> true;
cacheable(content_types_provided) -> true;
Expand Down Expand Up @@ -99,24 +98,40 @@ respond(Code, Headers, Rs, Rd) ->
RdHs = wrq:set_resp_headers(Headers, Rd),
respond(Code, Rs, RdHs).


error_response(Code, _Reason, Rs, Rd)
when Code == 403; Code == 404; Code == 304 ->
respond(403, Rs, Rd);
error_response(Code, Reason, Rs, Rd) ->
{ok, ErrorHandler} = application:get_env(webzmachine, error_handler),
{ErrorHTML, Rd1} = ErrorHandler:render_error(Code, Rd, Reason),
Rd2 = wrq:set_resp_body(ErrorHTML, Rd1),
respond(Code, Rs, Rd2).
RdResp = wrq:set_response_code(Code, Rd2),
resource_call(finish_request, Rs, RdResp).

error_response({error, Reason}, Rs, Rd) ->
error_response(reason_to_code(Reason), Reason, Rs, Rd);
error_response({error, Reason0, Reason1}, Rs, Rd) ->
error_response(reason_to_code(Reason0), {Reason0, Reason1}, Rs, Rd);
error_response(Reason, Rs, Rd) ->
error_response(500, Reason, Rs, Rd).
error_response(reason_to_code(Reason), Reason, Rs, Rd).

reason_to_code({throw, Error, _Trace}) -> reason_to_code(Error);
reason_to_code({bad_request, _}) -> 400;
reason_to_code(timeout) -> 503;
reason_to_code(_) -> 500.


decision_test({Test, Rs, Rd}, TestVal, TrueFlow, FalseFlow) ->
decision_test(Test, TestVal, TrueFlow, FalseFlow, Rs, Rd).

decision_test(Test,TestVal,TrueFlow,FalseFlow, Rs, Rd) ->
case Test of
{error, Reason} -> error_response(Reason, Rs, Rd);
{error, Reason0, Reason1} -> error_response({Reason0, Reason1}, Rs, Rd);
{halt, Code} -> respond(Code, Rs, Rd);
TestVal -> decision_flow(TrueFlow, Test, Rs, Rd);
_ -> decision_flow(FalseFlow, Test, Rs, Rd)
{error, Reason} -> error_response(Reason, Rs, Rd);
{error, Reason0, Reason1} -> error_response({Reason0, Reason1}, Rs, Rd);
{halt, Code} -> respond(Code, Rs, Rd);
TestVal -> decision_flow(TrueFlow, Test, Rs, Rd);
_ -> decision_flow(FalseFlow, Test, Rs, Rd)
end.

decision_test_fn({Test, Rs, Rd}, TestFn, TrueFlow, FalseFlow) ->
Expand Down Expand Up @@ -164,7 +179,7 @@ do_log(LogData) ->
%% "Service Available"
decision(v3b13, Rs, Rd) ->
decision_test(resource_call(ping, Rs, Rd), pong, v3b13b, 503);
decision(v3b13b, Rs, Rd) ->
decision(v3b13b, Rs, Rd) ->
decision_test(resource_call(service_available, Rs, Rd), true, v3b12, 503);
%% "Known method?"
decision(v3b12, Rs, Rd) ->
Expand All @@ -177,11 +192,11 @@ decision(v3b11, Rs, Rd) ->
decision(v3b10, Rs, Rd) ->
{Methods, Rs1, Rd1} = resource_call(allowed_methods, Rs, Rd),
case lists:member(method(Rd1), Methods) of
true ->
d(v3b9, Rs1, Rd1);
false ->
RdAllow = wrq:set_resp_header("Allow", string:join([atom_to_list(M) || M <- Methods], ", "), Rd1),
respond(405, Rs1, RdAllow)
true ->
d(v3b9, Rs1, Rd1);
false ->
RdAllow = wrq:set_resp_header("Allow", string:join([atom_to_list(M) || M <- Methods], ", "), Rd1),
respond(405, Rs1, RdAllow)
end;
%% "Malformed?"
decision(v3b9, Rs, Rd) ->
Expand All @@ -190,12 +205,12 @@ decision(v3b9, Rs, Rd) ->
decision(v3b8, Rs, Rd) ->
{IsAuthorized, Rs1, Rd1} = resource_call(is_authorized, Rs, Rd),
case IsAuthorized of
true ->
d(v3b7, Rs1, Rd1);
{error, Reason} ->
error_response(Reason, Rs1, Rd1);
{halt, Code} ->
respond(Code, Rs1, Rd1);
true ->
d(v3b7, Rs1, Rd1);
{error, Reason} ->
error_response(Reason, Rs1, Rd1);
{halt, Code} ->
respond(Code, Rs1, Rd1);
AuthHead ->
RdAuth = wrq:set_resp_header("WWW-Authenticate", AuthHead, Rd1),
respond(401, Rs1, RdAuth)
Expand All @@ -206,28 +221,28 @@ decision(v3b7, Rs, Rd) ->
%% "Upgrade?"
decision(v3b6_upgrade, Rs, Rd) ->
case get_header_val("upgrade", Rd) of
undefined ->
decision(v3b6, Rs, Rd);
UpgradeHdr ->
case get_header_val("connection", Rd) of
undefined ->
decision(v3b6, Rs, Rd);
Connection ->
case string:strip(string:to_lower(Connection)) of
"upgrade" ->
{Choosen, Rs1, Rd1} = choose_upgrade(UpgradeHdr, Rs, Rd),
case Choosen of
none ->
decision(v3b6, Rs1, Rd1);
{_Protocol, UpgradeFunc} ->
%% TODO: log the upgrade action
{upgrade, UpgradeFunc, Rs1, Rd1}
end;
_ ->
decision(v3b6, Rs, Rd)
end
end
end;
undefined ->
decision(v3b6, Rs, Rd);
UpgradeHdr ->
case get_header_val("connection", Rd) of
undefined ->
decision(v3b6, Rs, Rd);
Connection ->
case string:strip(string:to_lower(Connection)) of
"upgrade" ->
{Choosen, Rs1, Rd1} = choose_upgrade(UpgradeHdr, Rs, Rd),
case Choosen of
none ->
decision(v3b6, Rs1, Rd1);
{_Protocol, UpgradeFunc} ->
%% TODO: log the upgrade action
{upgrade, UpgradeFunc, Rs1, Rd1}
end;
_ ->
decision(v3b6, Rs, Rd)
end
end
end;
%% "Okay Content-* Headers?"
decision(v3b6, Rs, Rd) ->
decision_test(resource_call(valid_content_headers, Rs, Rd), true, v3b5, 501);
Expand All @@ -240,34 +255,34 @@ decision(v3b4, Rs, Rd) ->
%% "OPTIONS?"
decision(v3b3, Rs, Rd) ->
case wrq:method(Rd) of
'OPTIONS' ->
{Hdrs, Rs1, Rd1} = resource_call(options, Rs, Rd),
respond(200, Hdrs, Rs1, Rd1);
_ ->
d(v3c3, Rs, Rd)
'OPTIONS' ->
{Hdrs, Rs1, Rd1} = resource_call(options, Rs, Rd),
respond(200, Hdrs, Rs1, Rd1);
_ ->
d(v3c3, Rs, Rd)
end;
%% Accept exists?
decision(v3c3, Rs, Rd) ->
{ContentTypes, Rs1, Rd1} = resource_call(content_types_provided, Rs, Rd),
PTypes = [Type || {Type,_Fun} <- ContentTypes],
case get_header_val("accept", Rd1) of
undefined ->
{ok, RdCT} = webmachine_request:set_metadata('content-type', hd(PTypes), Rd1),
d(v3d4, Rs1, RdCT);
_ ->
d(v3c4, Rs1, Rd1)
undefined ->
{ok, RdCT} = webmachine_request:set_metadata('content-type', hd(PTypes), Rd1),
d(v3d4, Rs1, RdCT);
_ ->
d(v3c4, Rs1, Rd1)
end;
%% Acceptable media type available?
decision(v3c4, Rs, Rd) ->
{ContentTypesProvided, Rs1, Rd1} = resource_call(content_types_provided, Rs, Rd),
PTypes = [Type || {Type,_Fun} <- ContentTypesProvided],
AcceptHdr = get_header_val("accept", Rd1),
case webmachine_util:choose_media_type(PTypes, AcceptHdr) of
none ->
respond(406, Rs1, Rd1);
MType ->
{ok, RdCT} = webmachine_request:set_metadata('content-type', MType, Rd1),
d(v3d4, Rs, RdCT)
none ->
respond(406, Rs1, Rd1);
MType ->
{ok, RdCT} = webmachine_request:set_metadata('content-type', MType, Rd1),
d(v3d4, Rs, RdCT)
end;
%% Accept-Language exists?
decision(v3d4, Rs, Rd) ->
Expand Down Expand Up @@ -341,15 +356,15 @@ decision(v3h12, Rs, Rd) ->
decision(v3i4, Rs, Rd) ->
{MovedPermanently, Rs1, Rd1} = resource_call(moved_permanently, Rs, Rd),
case MovedPermanently of
{true, MovedURI} ->
RdLoc = wrq:set_resp_header("Location", MovedURI, Rd1),
respond(301, Rs1, RdLoc);
false ->
d(v3p3, Rs1, Rd1);
{error, Reason} ->
error_response(Reason, Rs1, Rd1);
{halt, Code} ->
respond(Code, Rs1, Rd1)
{true, MovedURI} ->
RdLoc = wrq:set_resp_header("Location", MovedURI, Rd1),
respond(301, Rs1, RdLoc);
false ->
d(v3p3, Rs1, Rd1);
{error, Reason} ->
error_response(Reason, Rs1, Rd1);
{halt, Code} ->
respond(Code, Rs1, Rd1)
end;
%% PUT?
decision(v3i7, Rs, Rd) ->
Expand All @@ -367,15 +382,15 @@ decision(v3j18, Rs, Rd) ->
decision(v3k5, Rs, Rd) ->
{MovedPermanently, Rs1, Rd1} = resource_call(moved_permanently, Rs, Rd),
case MovedPermanently of
{true, MovedURI} ->
RdLoc = wrq:set_resp_header("Location", MovedURI, Rd1),
respond(301, Rs1, RdLoc);
false ->
d(v3l5, Rs1, Rd1);
{error, Reason} ->
error_response(Reason, Rs1, Rd1);
{halt, Code} ->
respond(Code, Rs1, Rd1)
{true, MovedURI} ->
RdLoc = wrq:set_resp_header("Location", MovedURI, Rd1),
respond(301, Rs1, RdLoc);
false ->
d(v3l5, Rs1, Rd1);
{error, Reason} ->
error_response(Reason, Rs1, Rd1);
{halt, Code} ->
respond(Code, Rs1, Rd1)
end;
%% "Previously existed?"
decision(v3k7, Rs, Rd) ->
Expand All @@ -393,15 +408,15 @@ decision(v3k13, Rs, Rd) ->
decision(v3l5, Rs, Rd) ->
{MovedTemporarily, Rs1, Rd1} = resource_call(moved_temporarily, Rs, Rd),
case MovedTemporarily of
{true, MovedURI} ->
RdLoc = wrq:set_resp_header("Location", MovedURI, Rd1),
respond(307, Rs1, RdLoc);
false ->
d(v3m5, Rs1, Rd1);
{error, Reason} ->
error_response(Reason, Rs1, Rd1);
{halt, Code} ->
respond(Code, Rs1, Rd1)
{true, MovedURI} ->
RdLoc = wrq:set_resp_header("Location", MovedURI, Rd1),
respond(307, Rs1, RdLoc);
false ->
d(v3m5, Rs1, Rd1);
{error, Reason} ->
error_response(Reason, Rs1, Rd1);
{halt, Code} ->
respond(Code, Rs1, Rd1)
end;
%% "POST?"
decision(v3l7, Rs, Rd) ->
Expand Down Expand Up @@ -679,15 +694,15 @@ choose_encoding(AccEncHdr, Rs, Rd) ->
{EncodingsProvided, Rs1, Rd1} = resource_call(encodings_provided, Rs, Rd),
Encs = [Enc || {Enc,_Fun} <- EncodingsProvided],
case webmachine_util:choose_encoding(Encs, AccEncHdr) of
none ->
{none, Rs1, Rd1};
ChosenEnc ->
none ->
{none, Rs1, Rd1};
ChosenEnc ->
RdEnc = case ChosenEnc of
"identity" -> Rd1;
_ -> wrq:set_resp_header("Content-Encoding",ChosenEnc, Rd1)
end,
{ok, RdEnc1} = webmachine_request:set_metadata('content-encoding',ChosenEnc,RdEnc),
{ChosenEnc, Rs1, RdEnc1}
{ChosenEnc, Rs1, RdEnc1}
end.

choose_charset(AccCharHdr, Rs, Rd) ->
Expand All @@ -708,19 +723,19 @@ choose_charset(AccCharHdr, Rs, Rd) ->

choose_upgrade(UpgradeHdr, Rs, Rd) ->
{UpgradesProvided, Rs1, Rd1} = resource_call(upgrades_provided, Rs, Rd),
Provided1 = [ {string:to_lower(Prot), Prot, PFun} || {Prot, PFun} <- UpgradesProvided],
Requested = [ string:to_lower(string:strip(Up)) || Up <- string:tokens(UpgradeHdr, ",") ],
{choose_upgrade1(Requested, Provided1), Rs1, Rd1}.
Provided1 = [ {string:to_lower(Prot), Prot, PFun} || {Prot, PFun} <- UpgradesProvided],
Requested = [ string:to_lower(string:strip(Up)) || Up <- string:tokens(UpgradeHdr, ",") ],
{choose_upgrade1(Requested, Provided1), Rs1, Rd1}.

choose_upgrade1([], _) ->
none;
choose_upgrade1([Req|Requested], Provided) ->
case lists:keysearch(Req, 1, Provided) of
false ->
choose_upgrade1(Requested, Provided);
{value, {_, Protocol, UpgradeFun}} ->
{Protocol, UpgradeFun}
end.
choose_upgrade1([], _) ->
none;
choose_upgrade1([Req|Requested], Provided) ->
case lists:keysearch(Req, 1, Provided) of
false ->
choose_upgrade1(Requested, Provided);
{value, {_, Protocol, UpgradeFun}} ->
{Protocol, UpgradeFun}
end.


variances(Rs, Rd) ->
Expand All @@ -732,9 +747,9 @@ variances(Rs, Rd) ->
end,
{EncodingsProvided, Rs2, Rd2} = resource_call(encodings_provided, Rs1, Rd1),
AcceptEncoding = case length(EncodingsProvided) of
1 -> [];
0 -> [];
_ -> ["Accept-Encoding"]
1 -> [];
0 -> [];
_ -> ["Accept-Encoding"]
end,
{CharsetsProvided, Rs3, Rd3} = resource_call(charsets_provided, Rs2, Rd2),
AcceptCharset = case CharsetsProvided of
Expand Down
4 changes: 4 additions & 0 deletions src/webmachine_error_handler.erl
View file
Original file line number Diff line number Diff line change
Expand Up @@ -31,6 +31,10 @@ render_error(Code, ReqData, Reason) ->
{false,_} -> render_error_body(Code, ReqData, Reason)
end.

render_error_body(400, ReqData, _Reason) ->
ReqData1 = wrq:set_resp_header("Content-Type", "text/html", ReqData),
{<<"<HTML><HEAD><TITLE>400 Bad Request</TITLE></HEAD><BODY><H1>Bad Request</H1>The request was invalid.<P><HR><ADDRESS>mochiweb+webmachine web server</ADDRESS></BODY></HTML>">>, ReqData1};

render_error_body(404, ReqData, _Reason) ->
ReqData1 = wrq:set_resp_header("Content-Type", "text/html", ReqData),
{<<"<HTML><HEAD><TITLE>404 Not Found</TITLE></HEAD><BODY><H1>Not Found</H1>The requested document was not found on this server.<P><HR><ADDRESS>mochiweb+webmachine web server</ADDRESS></BODY></HTML>">>, ReqData1};
Expand Down
4 changes: 2 additions & 2 deletions src/webmachine_mochiweb.erl
View file
Original file line number Diff line number Diff line change
Expand Up @@ -140,8 +140,8 @@ loop(MochiReq, LoopOpts) ->
erlang:put(mochiweb_request_force_close, true)
end
catch
error:_ ->
?WM_DBG({error, erlang:get_stacktrace()}),
error:E ->
?WM_DBG({error, E, erlang:get_stacktrace()}),
{ok,RD3} = webmachine_request:send_response(500, RD2),
Resource:stop(RD3),
case application:get_env(webzmachine, webmachine_logger_module) of
Expand Down

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