jsx/src/jsx_format.erl

258 lines
No EOL
7.8 KiB
Erlang

%% The MIT License
%% Copyright (c) 2010 Alisdair Sullivan <alisdairsullivan@yahoo.ca>
%% 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_format).
-export([format/2]).
-include("./include/jsx_common.hrl").
-include("./include/jsx_format.hrl").
-ifdef(TEST).
-include_lib("eunit/include/eunit.hrl").
-endif.
-spec format(JSON::binary(), Opts::format_opts()) -> binary() | iolist().
format(JSON, Opts) when is_binary(JSON) ->
P = jsx:decoder(extract_parser_opts(Opts)),
format(fun() -> P(JSON) end, Opts);
format(F, OptsList) when is_function(F) ->
Opts = parse_opts(OptsList, #format_opts{}),
{Continue, String} = format_something(F(), Opts, 0),
case Continue() of
{event, end_json, _} -> encode(String, Opts)
; _ -> {error, badarg}
end.
parse_opts([{indent, Val}|Rest], Opts) ->
parse_opts(Rest, Opts#format_opts{indent = Val});
parse_opts([indent|Rest], Opts) ->
parse_opts(Rest, Opts#format_opts{indent = 1});
parse_opts([{space, Val}|Rest], Opts) ->
parse_opts(Rest, Opts#format_opts{space = Val});
parse_opts([space|Rest], Opts) ->
parse_opts(Rest, Opts#format_opts{space = 1});
parse_opts([{output_encoding, Val}|Rest], Opts) ->
parse_opts(Rest, Opts#format_opts{output_encoding = Val});
parse_opts([_|Rest], Opts) ->
parse_opts(Rest, Opts);
parse_opts([], Opts) ->
Opts.
extract_parser_opts(Opts) ->
extract_parser_opts(Opts, []).
extract_parser_opts([], Acc) -> Acc;
extract_parser_opts([{K,V}|Rest], Acc) ->
case lists:member(K, [comments, encoding, unquoted_keys]) of
true -> [{K,V}] ++ Acc
; false -> extract_parser_opts(Rest, Acc)
end;
extract_parser_opts([K|Rest], Acc) ->
case lists:member(K, [comments, encoding, unquoted_keys]) of
true -> [K] ++ Acc
; false -> extract_parser_opts(Rest, Acc)
end.
format_something({event, start_object, Next}, Opts, Level) ->
case Next() of
{event, end_object, Continue} ->
{Continue, [?start_object, ?end_object]}
; Event ->
{Continue, Object} = format_object(Event, [], Opts, Level + 1),
{Continue, [?start_object,
Object,
indent(Opts, Level),
?end_object
]}
end;
format_something({event, start_array, Next}, Opts, Level) ->
case Next() of
{event, end_array, Continue} ->
{Continue, [?start_array, ?end_array]}
; Event ->
{Continue, Object} = format_array(Event, [], Opts, Level + 1),
{Continue, [?start_array, Object, indent(Opts, Level), ?end_array]}
end;
format_something({event, {Type, Value}, Next}, _Opts, _Level) ->
{Next, [encode(Type, Value)]}.
format_object({event, end_object, Next}, Acc, _Opts, _Level) ->
{Next, Acc};
format_object({event, {key, Key}, Next}, Acc, Opts, Level) ->
{Continue, Value} = format_something(Next(), Opts, Level),
case Continue() of
{event, end_object, NextNext} ->
{NextNext, [Acc,
indent(Opts, Level),
encode(string, Key),
?colon,
space(Opts),
Value
]}
; Else ->
format_object(Else,
[Acc,
indent(Opts, Level),
encode(string, Key),
?colon,
space(Opts),
Value,
?comma,
space(Opts)
],
Opts,
Level
)
end.
format_array({event, end_array, Next}, Acc, _Opts, _Level) ->
{Next, Acc};
format_array(Event, Acc, Opts, Level) ->
{Continue, Value} = format_something(Event, Opts, Level),
case Continue() of
{event, end_array, NextNext} ->
{NextNext, [Acc, indent(Opts, Level), Value]}
; Else ->
format_array(Else,
[Acc,
indent(Opts, Level),
Value,
?comma,
space(Opts)
],
Opts,
Level
)
end.
encode(Acc, Opts) when is_list(Acc) ->
case Opts#format_opts.output_encoding of
iolist -> Acc
; UTF when ?is_utf_encoding(UTF) ->
unicode:characters_to_binary(Acc, utf8, UTF)
; _ -> erlang:error(badarg)
end;
encode(string, String) ->
[?quote, String, ?quote];
encode(literal, Literal) ->
erlang:atom_to_list(Literal);
encode(_, Number) ->
Number.
indent(Opts, Level) ->
case Opts#format_opts.indent of
0 -> []
; X when X > 0 ->
Indent = [ ?space || _ <- lists:seq(1, X) ],
indent(Indent, Level, [?newline])
end.
indent(_Indent, 0, Acc) ->
Acc;
indent(Indent, N, Acc) ->
indent(Indent, N - 1, [Acc, Indent]).
space(Opts) ->
case Opts#format_opts.space of
0 -> []
; X when X > 0 -> [ ?space || _ <- lists:seq(1, X) ]
end.
%% eunit tests
-ifdef(TEST).
minify_test_() ->
[
{"minify object",
?_assert(format(<<" { \"key\" :\n\t \"value\"\r\r\r\n } ">>,
[]
) =:= <<"{\"key\":\"value\"}">>
)
},
{"minify array",
?_assert(format(<<" [\n\ttrue,\n\tfalse,\n\tnull\n] ">>,
[]
) =:= <<"[true,false,null]">>
)
}
].
opts_test_() ->
[
{"unspecified indent/space",
?_assert(format(<<" [\n\ttrue,\n\tfalse,\n\tnull\n] ">>,
[space, indent]
) =:= <<"[\n true, \n false, \n null\n]">>
)
},
{"specific indent/space",
?_assert(format(
<<"\n{\n\"key\" : [],\n\"another key\" : true\n}\n">>,
[{space, 2}, {indent, 3}]
) =:= <<"{\n \"key\": [], \n \"another key\": true\n}">>
)
},
{"nested structures",
?_assert(format(
<<"[{\"key\":\"value\",
\"another key\": \"another value\"
},
[[true, false, null]]
]">>,
[{space, 2}, {indent, 2}]
) =:= <<"[\n {\n \"key\": \"value\", \n \"another key\": \"another value\"\n }, \n [\n [\n true, \n false, \n null\n ]\n ]\n]">>
)
},
{"just spaces",
?_assert(format(<<"[1,2,3]">>,
[{space, 2}]
) =:= <<"[1, 2, 3]">>
)
},
{"just indent",
?_assert(format(<<"[1.0, 2.0, 3.0]">>,
[{indent, 2}]
) =:= <<"[\n 1.0,\n 2.0,\n 3.0\n]">>
)
}
].
-endif.