[ViewVC] Diff of: cvs/JSON-XS/XS.pm

Comparing JSON-XS/XS.pm (file contents):
Revision 1.108 by root, Tue Jul 15 11:29:29 2008 UTC vs.
Revision 1.122 by root, Fri Jul 17 14:33:45 2009 UTC

…		…
49	to write yet another JSON module? While it seems there are many JSON	49	to write yet another JSON module? While it seems there are many JSON
50	modules, none of them correctly handle all corner cases, and in most cases	50	modules, none of them correctly handle all corner cases, and in most cases
51	their maintainers are unresponsive, gone missing, or not listening to bug	51	their maintainers are unresponsive, gone missing, or not listening to bug
52	reports for other reasons.	52	reports for other reasons.
53		53
54	See COMPARISON, below, for a comparison to some other JSON modules.
55
56	See MAPPING, below, on how JSON::XS maps perl values to JSON values and	54	See MAPPING, below, on how JSON::XS maps perl values to JSON values and
57	vice versa.	55	vice versa.
58		56
59	=head2 FEATURES	57	=head2 FEATURES
60		58
…		…
101		99
102	=cut	100	=cut
103		101
104	package JSON::XS;	102	package JSON::XS;
105		103
106	use strict;	104	use common::sense;
107		105
108	our $VERSION = '2.22';	106	our $VERSION = '2.24';
109	our @ISA = qw(Exporter);	107	our @ISA = qw(Exporter);
110		108
111	our @EXPORT = qw(encode_json decode_json to_json from_json);	109	our @EXPORT = qw(encode_json decode_json to_json from_json);
112		110
113	sub to_json($) {	111	sub to_json($) {
…		…
442	the same JSON text (given the same overall settings). If it is disabled,	440	the same JSON text (given the same overall settings). If it is disabled,
443	the same hash might be encoded differently even if contains the same data,	441	the same hash might be encoded differently even if contains the same data,
444	as key-value pairs have no inherent ordering in Perl.	442	as key-value pairs have no inherent ordering in Perl.
445		443
446	This setting has no effect when decoding JSON texts.	444	This setting has no effect when decoding JSON texts.
		445
		446	This setting has currently no effect on tied hashes.
447		447
448	=item $json = $json->allow_nonref ([$enable])	448	=item $json = $json->allow_nonref ([$enable])
449		449
450	=item $enabled = $json->get_allow_nonref	450	=item $enabled = $json->get_allow_nonref
451		451
…		…
767	JSON object or b) parsing multiple JSON objects separated by non-JSON text	767	JSON object or b) parsing multiple JSON objects separated by non-JSON text
768	(such as commas).	768	(such as commas).
769		769
770	=item $json->incr_skip	770	=item $json->incr_skip
771		771
772	This will reset the state of the incremental parser and will remove the	772	This will reset the state of the incremental parser and will remove
773	parsed text from the input buffer. This is useful after C<incr_parse>	773	the parsed text from the input buffer so far. This is useful after
774	died, in which case the input buffer and incremental parser state is left	774	C<incr_parse> died, in which case the input buffer and incremental parser
775	unchanged, to skip the text parsed so far and to reset the parse state.	775	state is left unchanged, to skip the text parsed so far and to reset the
		776	parse state.
		777
		778	The difference to C<incr_reset> is that only text until the parse error
		779	occured is removed.
776		780
777	=item $json->incr_reset	781	=item $json->incr_reset
778		782
779	This completely resets the incremental parser, that is, after this call,	783	This completely resets the incremental parser, that is, after this call,
780	it will be as if the parser had never parsed anything.	784	it will be as if the parser had never parsed anything.
781		785
782	This is useful if you want ot repeatedly parse JSON objects and want to	786	This is useful if you want to repeatedly parse JSON objects and want to
783	ignore any trailing data, which means you have to reset the parser after	787	ignore any trailing data, which means you have to reset the parser after
784	each successful decode.	788	each successful decode.
785		789
786	=back	790	=back
787		791
…		…
1180	when your channel for JSON transfer is not 8-bit clean or the encoding	1184	when your channel for JSON transfer is not 8-bit clean or the encoding
1181	might be mangled in between (e.g. in mail), and works because ASCII is a	1185	might be mangled in between (e.g. in mail), and works because ASCII is a
1182	proper subset of most 8-bit and multibyte encodings in use in the world.	1186	proper subset of most 8-bit and multibyte encodings in use in the world.
1183		1187
1184	=back	1188	=back
		1189
		1190
		1191	=head2 JSON and ECMAscript
		1192
		1193	JSON syntax is based on how literals are represented in javascript (the
		1194	not-standardised predecessor of ECMAscript) which is presumably why it is
		1195	called "JavaScript Object Notation".
		1196
		1197	However, JSON is not a subset (and also not a superset of course) of
		1198	ECMAscript (the standard) or javascript (whatever browsers actually
		1199	implement).
		1200
		1201	If you want to use javascript's C<eval> function to "parse" JSON, you
		1202	might run into parse errors for valid JSON texts, or the resulting data
		1203	structure might not be queryable:
		1204
		1205	One of the problems is that U+2028 and U+2029 are valid characters inside
		1206	JSON strings, but are not allowed in ECMAscript string literals, so the
		1207	following Perl fragment will not output something that can be guaranteed
		1208	to be parsable by javascript's C<eval>:
		1209
		1210	use JSON::XS;
		1211
		1212	print encode_json [chr 0x2028];
		1213
		1214	The right fix for this is to use a proper JSON parser in your javascript
		1215	programs, and not rely on C<eval> (see for example Douglas Crockford's
		1216	F<json2.js> parser).
		1217
		1218	If this is not an option, you can, as a stop-gap measure, simply encode to
		1219	ASCII-only JSON:
		1220
		1221	use JSON::XS;
		1222
		1223	print JSON::XS->new->ascii->encode ([chr 0x2028]);
		1224
		1225	Note that this will enlarge the resulting JSON text quite a bit if you
		1226	have many non-ASCII characters. You might be tempted to run some regexes
		1227	to only escape U+2028 and U+2029, e.g.:
		1228
		1229	# DO NOT USE THIS!
		1230	my $json = JSON::XS->new->utf8->encode ([chr 0x2028]);
		1231	$json =~ s/\xe2\x80\xa8/\\u2028/g; # escape U+2028
		1232	$json =~ s/\xe2\x80\xa9/\\u2029/g; # escape U+2029
		1233	print $json;
		1234
		1235	Note that I<this is a bad idea>: the above only works for U+2028 and
		1236	U+2029 and thus only for fully ECMAscript-compliant parsers. Many existing
		1237	javascript implementations, however, have issues with other characters as
		1238	well - using C<eval> naively simply I<will> cause problems.
		1239
		1240	Another problem is that some javascript implementations reserve
		1241	some property names for their own purposes (which probably makes
		1242	them non-ECMAscript-compliant). For example, Iceweasel reserves the
		1243	C<__proto__> property name for it's own purposes.
		1244
		1245	If that is a problem, you could parse try to filter the resulting JSON
		1246	output for these property strings, e.g.:
		1247
		1248	$json =~ s/"__proto__"\s*:/"__proto__renamed":/g;
		1249
		1250	This works because C<__proto__> is not valid outside of strings, so every
		1251	occurence of C<"__proto__"\s*:> must be a string used as property name.
		1252
		1253	If you know of other incompatibilities, please let me know.
1185		1254
1186		1255
1187	=head2 JSON and YAML	1256	=head2 JSON and YAML
1188		1257
1189	You often hear that JSON is a subset of YAML. This is, however, a mass	1258	You often hear that JSON is a subset of YAML. This is, however, a mass

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Comparing JSON-XS/XS.pm (file contents): Revision 1.108 by root, Tue Jul 15 11:29:29 2008 UTC vs. Revision 1.122 by root, Fri Jul 17 14:33:45 2009 UTC

Diff Legend

Comparing JSON-XS/XS.pm (file contents):
Revision 1.108 by root, Tue Jul 15 11:29:29 2008 UTC vs.
Revision 1.122 by root, Fri Jul 17 14:33:45 2009 UTC