… | |
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348 | enabled by this setting. |
348 | enabled by this setting. |
349 | |
349 | |
350 | If C<$enable> is false, then the C<allow_blessed> setting will decide what |
350 | If C<$enable> is false, then the C<allow_blessed> setting will decide what |
351 | to do when a blessed object is found. |
351 | to 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->($hashref)]) |
354 | |
354 | |
355 | When C<$coderef> is specified, it will be called from C<decode> each |
355 | When C<$coderef> is specified, it will be called from C<decode> each |
356 | time it decodes a JSON object. The only argument is a reference to the |
356 | time it decodes a JSON object. The only argument is a reference to the |
357 | newly-created hash. If the code references returns a single scalar (which |
357 | newly-created hash. If the code references returns a single scalar (which |
358 | need not be a reference), this value (i.e. a copy of that scalar to avoid |
358 | need not be a reference), this value (i.e. a copy of that scalar to avoid |
359 | aliasing) is inserted into the deserialised data structure. If it returns |
359 | aliasing) is inserted into the deserialised data structure. If it returns |
360 | an empty list (NOTE: I<not> C<undef>, which is a valid scalar), the |
360 | an empty list (NOTE: I<not> C<undef>, which is a valid scalar), the |
361 | original deserialised hash will be inserted. This setting can slow down |
361 | original deserialised hash will be inserted. This setting can slow down |
362 | decoding considerably. |
362 | decoding considerably. |
363 | |
363 | |
364 | When C<$coderef> is omitted or undefined, C<decode> will not change the |
364 | When C<$coderef> is omitted or undefined, any existing callback will |
365 | deserialised hash in any way. This is maximally fast. |
365 | be removed and C<decode> will not change the deserialised hash in any |
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366 | way. |
366 | |
367 | |
367 | Example, convert all JSON objects into the integer 5: |
368 | Example, 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 | |
377 | Works like C<filter_json_object>, but is only called for JSON objects |
379 | Works remotely similar to C<filter_json_object>, but is only called for |
378 | having only a single key. |
380 | JSON objects having a single key named C<$key>. |
379 | |
381 | |
380 | This C<$coderef> is called before the one specified via |
382 | This C<$coderef> is called before the one specified via |
381 | C<filter_json_object>, if any. If it returns something, that will be |
383 | C<filter_json_object>, if any. It gets passed the single value in the JSON |
382 | inserted into the data structure. If it returns nothing, the callback |
384 | object. If it returns a single value, it will be inserted into the data |
383 | from C<filter_json_object> will be called next. If you want to force |
385 | structure. If it returns nothing (not even C<undef> but the empty list), |
384 | insertion of single-key objects even in the presence of a mutating |
386 | the callback from C<filter_json_object> will be called next, as if no |
385 | C<filter_json_object> callback, simply return the passed hash. |
387 | single-key callback were specified. |
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388 | |
|
|
389 | If C<$coderef> is omitted or undefined, the corresponding callback will be |
|
|
390 | disabled. There can only ever be one callback for a given key. |
386 | |
391 | |
387 | As this callback gets called less often then the C<filter_json_object> |
392 | As this callback gets called less often then the C<filter_json_object> |
388 | one, decoding speed will not usually suffer as much. Therefore, single-key |
393 | one, decoding speed will not usually suffer as much. Therefore, single-key |
389 | objects make excellent targets to serialise Perl objects into, especially |
394 | objects make excellent targets to serialise Perl objects into, especially |
390 | as single-key JSON objects are as close to the type-tagged value concept |
395 | as single-key JSON objects are as close to the type-tagged value concept |
… | |
… | |
401 | into the corresponding C<< $WIDGET{<id>} >> object: |
406 | into 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: |
… | |
… | |
875 | still relatively early in its development. If you keep reporting bugs they |
878 | still relatively early in its development. If you keep reporting bugs they |
876 | will be fixed swiftly, though. |
879 | will be fixed swiftly, though. |
877 | |
880 | |
878 | =cut |
881 | =cut |
879 | |
882 | |
880 | our $true = do { bless \(my $dummy = "1"), "JSON::XS::Boolean" }; |
883 | our $true = do { bless \(my $dummy = 1), "JSON::XS::Boolean" }; |
881 | our $false = do { bless \(my $dummy = "0"), "JSON::XS::Boolean" }; |
884 | our $false = do { bless \(my $dummy = 0), "JSON::XS::Boolean" }; |
882 | |
885 | |
883 | sub true() { $true } |
886 | sub true() { $true } |
884 | sub false() { $false } |
887 | sub false() { $false } |
885 | |
888 | |
886 | sub is_bool($) { |
889 | sub is_bool($) { |