%% The MIT License %% Copyright (c) 2011 Alisdair Sullivan %% Permission is hereby granted, free of charge, to any person obtaining a copy %% of this software and associated documentation files (the "Software"), to deal %% in the Software without restriction, including without limitation the rights %% to use, copy, modify, merge, publish, distribute, sublicense, and/or sell %% copies of the Software, and to permit persons to whom the Software is %% furnished to do so, subject to the following conditions: %% The above copyright notice and this permission notice shall be included in %% all copies or substantial portions of the Software. %% THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR %% IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, %% FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE %% AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER %% LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, %% OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN %% THE SOFTWARE. -module(jsx_encoder). -export([encoder/3]). -spec encoder(Handler::module(), State::any(), Opts::jsx:opts()) -> jsx:encoder(). encoder(Handler, State, Opts) -> fun(JSON) -> start( JSON, {Handler, Handler:init(State)}, jsx_utils:parse_opts(Opts) ) end. -include("jsx_opts.hrl"). -ifndef(error). -define(error(Args), erlang:error(badarg, Args) ). -endif. start(Term, {Handler, State}, Opts) -> Handler:handle_event(end_json, value(Term, {Handler, State}, Opts)). value(String, {Handler, State}, Opts) when is_binary(String) -> Handler:handle_event({string, clean_string(String, Opts)}, State); value(Float, {Handler, State}, _Opts) when is_float(Float) -> Handler:handle_event({float, Float}, State); value(Int, {Handler, State}, _Opts) when is_integer(Int) -> Handler:handle_event({integer, Int}, State); value(Literal, {Handler, State}, _Opts) when Literal == true; Literal == false; Literal == null -> Handler:handle_event({literal, Literal}, State); value([{}], {Handler, State}, _Opts) -> Handler:handle_event(end_object, Handler:handle_event(start_object, State)); value([], {Handler, State}, _Opts) -> Handler:handle_event(end_array, Handler:handle_event(start_array, State)); value(List, {Handler, State}, Opts) when is_list(List) -> list_or_object(List, {Handler, State}, Opts); value(Term, Handler, Opts) -> ?error([Term, Handler, Opts]). list_or_object([Tuple|_] = List, {Handler, State}, Opts) when is_tuple(Tuple) -> object(List, {Handler, Handler:handle_event(start_object, State)}, Opts); list_or_object(List, {Handler, State}, Opts) -> list(List, {Handler, Handler:handle_event(start_array, State)}, Opts). object([{Key, Value}|Rest], {Handler, State}, Opts) -> object( Rest, { Handler, value( Value, {Handler, Handler:handle_event({key, clean_string(fix_key(Key), Opts)}, State)}, Opts ) }, Opts ); object([], {Handler, State}, _Opts) -> Handler:handle_event(end_object, State); object(Term, Handler, Opts) -> ?error([Term, Handler, Opts]). list([Value|Rest], {Handler, State}, Opts) -> list(Rest, {Handler, value(Value, {Handler, State}, Opts)}, Opts); list([], {Handler, State}, _Opts) -> Handler:handle_event(end_array, State); list(Term, Handler, Opts) -> ?error([Term, Handler, Opts]). fix_key(Key) when is_atom(Key) -> fix_key(atom_to_binary(Key, utf8)); fix_key(Key) when is_binary(Key) -> Key. clean_string(Bin, Opts) -> case Opts#opts.json_escape of true -> jsx_utils:json_escape(Bin, Opts); false -> case is_clean(Bin) of true -> Bin; false -> clean_string(Bin, [], Opts) end end. is_clean(<<>>) -> true; is_clean(<<_/utf8, Rest/binary>>) -> is_clean(Rest); is_clean(_) -> false. clean_string(Bin, _Acc, Opts=#opts{loose_unicode=false}) -> ?error([Bin, Opts]); clean_string(<<>>, Acc, _Opts) -> unicode:characters_to_binary(lists:reverse(Acc)); clean_string(<>, Acc, Opts) -> clean_string(Rest, [X] ++ Acc, Opts); %% surrogates clean_string(<<237, X, _, Rest/binary>>, Acc, Opts) when X >= 160 -> clean_string(Rest, [16#fffd] ++ Acc, Opts); %% bad codepoints clean_string(<<_, Rest/binary>>, Acc, Opts) -> clean_string(Rest, [16#fffd] ++ Acc, Opts). -ifdef(TEST). -include_lib("eunit/include/eunit.hrl"). encode(Term) -> (encoder(jsx, [], []))(Term). encode(Term, Opts) -> try (encoder(jsx, [], Opts))(Term) catch _:_ -> {error, badjson} end. encode_test_() -> [ {"naked string", ?_assertEqual(encode(<<"a string">>), [{string, <<"a string">>}, end_json])}, {"naked integer", ?_assertEqual(encode(123), [{integer, 123}, end_json])}, {"naked float", ?_assertEqual(encode(1.23), [{float, 1.23}, end_json])}, {"naked literal", ?_assertEqual(encode(null), [{literal, null}, end_json])}, {"empty object", ?_assertEqual(encode([{}]), [start_object, end_object, end_json])}, {"empty list", ?_assertEqual(encode([]), [start_array, end_array, end_json])}, {"simple list", ?_assertEqual( encode([1,2,3,true,false]), [ start_array, {integer, 1}, {integer, 2}, {integer, 3}, {literal, true}, {literal, false}, end_array, end_json ] ) }, {"simple object", ?_assertEqual( encode([{<<"a">>, true}, {<<"b">>, false}]), [ start_object, {key, <<"a">>}, {literal, true}, {key, <<"b">>}, {literal, false}, end_object, end_json ] ) }, {"complex term", ?_assertEqual( encode([ {<<"a">>, true}, {<<"b">>, false}, {<<"c">>, [1,2,3]}, {<<"d">>, [{<<"key">>, <<"value">>}]} ]), [ start_object, {key, <<"a">>}, {literal, true}, {key, <<"b">>}, {literal, false}, {key, <<"c">>}, start_array, {integer, 1}, {integer, 2}, {integer, 3}, end_array, {key, <<"d">>}, start_object, {key, <<"key">>}, {string, <<"value">>}, end_object, end_object, end_json ] ) }, {"atom keys", ?_assertEqual( encode([{key, <<"value">>}]), [start_object, {key, <<"key">>}, {string, <<"value">>}, end_object, end_json] ) } ]. surrogates_test_() -> [ {"surrogates - badjson", ?_assertEqual(check_bad(surrogates()), []) }, {"surrogates - replaced", ?_assertEqual(check_replaced(surrogates()), []) } ]. good_characters_test_() -> [ {"acceptable codepoints", ?_assertEqual(check_good(good()), []) }, {"acceptable extended", ?_assertEqual(check_good(good_extended()), []) } ]. malformed_test_() -> [ {"malformed codepoint with 1 byte", ?_assertError(badarg, encode(<<128>>))}, {"malformed codepoint with 2 bytes", ?_assertError(badarg, encode(<<128, 192>>))}, {"malformed codepoint with 3 bytes", ?_assertError(badarg, encode(<<128, 192, 192>>))}, {"malformed codepoint with 4 bytes", ?_assertError(badarg, encode(<<128, 192, 192, 192>>))} ]. malformed_replaced_test_() -> F = <<16#fffd/utf8>>, [ {"malformed codepoint with 1 byte", ?_assertEqual( [{string, <>}, end_json], encode(<<128>>, [loose_unicode]) ) }, {"malformed codepoint with 2 bytes", ?_assertEqual( [{string, <>}, end_json], encode(<<128, 192>>, [loose_unicode]) ) }, {"malformed codepoint with 3 bytes", ?_assertEqual( [{string, <>}, end_json], encode(<<128, 192, 192>>, [loose_unicode]) ) }, {"malformed codepoint with 4 bytes", ?_assertEqual( [{string, <>}, end_json], encode(<<128, 192, 192, 192>>, [loose_unicode]) ) } ]. check_bad(List) -> lists:dropwhile(fun({_, {error, badjson}}) -> true ; (_) -> false end, check(List, [], []) ). check_replaced(List) -> lists:dropwhile(fun({_, [{string, <<16#fffd/utf8>>}|_]}) -> true ; (_) -> false end, check(List, [loose_unicode], []) ). check_good(List) -> lists:dropwhile(fun({_, [{string, _}|_]}) -> true ; (_) -> false end, check(List, [], []) ). check([], _Opts, Acc) -> Acc; check([H|T], Opts, Acc) -> R = encode(to_fake_utf(H, utf8), Opts), check(T, Opts, [{H, R}] ++ Acc). surrogates() -> lists:seq(16#d800, 16#dfff). good() -> lists:seq(1, 16#d7ff) ++ lists:seq(16#e000, 16#fffd). good_extended() -> lists:seq(16#100000, 16#10ffff). %% erlang refuses to encode certain codepoints, so fake them all to_fake_utf(N, utf8) when N < 16#0080 -> <>; to_fake_utf(N, utf8) when N < 16#0800 -> <<0:5, Y:5, X:6>> = <>, <<2#110:3, Y:5, 2#10:2, X:6>>; to_fake_utf(N, utf8) when N < 16#10000 -> <> = <>, <<2#1110:4, Z:4, 2#10:2, Y:6, 2#10:2, X:6>>; to_fake_utf(N, utf8) -> <<0:3, W:3, Z:6, Y:6, X:6>> = <>, <<2#11110:5, W:3, 2#10:2, Z:6, 2#10:2, Y:6, 2#10:2, X:6>>. -endif.