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Comparing JSON-XS/XS.pm (file contents):
Revision 1.51 by root, Mon Jul 2 01:12:27 2007 UTC vs.
Revision 1.52 by root, Mon Jul 2 02:57:11 2007 UTC

… …
348enabled by this setting. 348enabled by this setting.
349 349
350If C<$enable> is false, then the C<allow_blessed> setting will decide what 350If C<$enable> is false, then the C<allow_blessed> setting will decide what
351to do when a blessed object is found. 351to do when a blessed object is found.
352 352
353=item $json = $json->filter_json_object ([$coderef]) 353=item $json = $json->filter_json_object ([$coderef->($hashref)])
354 354
355When C<$coderef> is specified, it will be called from C<decode> each 355When C<$coderef> is specified, it will be called from C<decode> each
356time it decodes a JSON object. The only argument is a reference to the 356time it decodes a JSON object. The only argument is a reference to the
357newly-created hash. If the code references returns a single scalar (which 357newly-created hash. If the code references returns a single scalar (which
358need not be a reference), this value (i.e. a copy of that scalar to avoid 358need not be a reference), this value (i.e. a copy of that scalar to avoid
359aliasing) is inserted into the deserialised data structure. If it returns 359aliasing) is inserted into the deserialised data structure. If it returns
360an empty list (NOTE: I<not> C<undef>, which is a valid scalar), the 360an empty list (NOTE: I<not> C<undef>, which is a valid scalar), the
361original deserialised hash will be inserted. This setting can slow down 361original deserialised hash will be inserted. This setting can slow down
362decoding considerably. 362decoding considerably.
363 363
364When C<$coderef> is omitted or undefined, C<decode> will not change the 364When C<$coderef> is omitted or undefined, any existing callback will
365deserialised hash in any way. This is maximally fast. 365be removed and C<decode> will not change the deserialised hash in any
366way.
366 367
367Example, convert all JSON objects into the integer 5: 368Example, convert all JSON objects into the integer 5:
368 369
369 my $js = JSON::XS->new->filter_json_object (sub { 5 }); 370 my $js = JSON::XS->new->filter_json_object (sub { 5 });
370 # returns [5] 371 # returns [5]
371 $js->decode ('[{}]') 372 $js->decode ('[{}]')
372 # throw an exception because allow_nonref is not enabled: 373 # throw an exception because allow_nonref is not enabled
374 # so a lone 5 is not allowed.
373 $js->decode ('{"a":1, "b":2}'); 375 $js->decode ('{"a":1, "b":2}');
374 376
375=item $json = $json->filter_json_single_key_object ([$coderef]) 377=item $json = $json->filter_json_single_key_object ($key [=> $coderef->($value)])
376 378
377Works like C<filter_json_object>, but is only called for JSON objects 379Works remotely similar to C<filter_json_object>, but is only called for
378having only a single key. 380JSON objects having a single key named C<$key>.
379 381
380This C<$coderef> is called before the one specified via 382This C<$coderef> is called before the one specified via
381C<filter_json_object>, if any. If it returns something, that will be 383C<filter_json_object>, if any. It gets passed the single value in the JSON
382inserted into the data structure. If it returns nothing, the callback 384object. If it returns a single value, it will be inserted into the data
383from C<filter_json_object> will be called next. If you want to force 385structure. If it returns nothing (not even C<undef> but the empty list),
384insertion of single-key objects even in the presence of a mutating 386the callback from C<filter_json_object> will be called next, as if no
385C<filter_json_object> callback, simply return the passed hash. 387single-key callback were specified.
388
389If C<$coderef> is omitted or undefined, the corresponding callback will be
390disabled. There can only ever be one callback for a given key.
386 391
387As this callback gets called less often then the C<filter_json_object> 392As this callback gets called less often then the C<filter_json_object>
388one, decoding speed will not usually suffer as much. Therefore, single-key 393one, decoding speed will not usually suffer as much. Therefore, single-key
389objects make excellent targets to serialise Perl objects into, especially 394objects make excellent targets to serialise Perl objects into, especially
390as single-key JSON objects are as close to the type-tagged value concept 395as single-key JSON objects are as close to the type-tagged value concept
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401into the corresponding C<< $WIDGET{<id>} >> object: 406into the corresponding C<< $WIDGET{<id>} >> object:
402 407
403 # return whatever is in $WIDGET{5}: 408 # return whatever is in $WIDGET{5}:
404 JSON::XS 409 JSON::XS
405 ->new 410 ->new
406 ->filter_json_single_key_object (sub { 411 ->filter_json_single_key_object (__widget__ => sub {
407 exists $_[0]{__widget__}
408 ? $WIDGET{ $_[0]{__widget__} } 412 $WIDGET{ $_[0] }
409 : ()
410 }) 413 })
411 ->decode ('{"__widget__": 5') 414 ->decode ('{"__widget__": 5')
412 415
413 # this can be used with a TO_JSON method in some "widget" class 416 # this can be used with a TO_JSON method in some "widget" class
414 # for serialisation to json: 417 # for serialisation to json:

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