add a quick reference for converting from JSON::Any

[p5sagit/JSON-MaybeXS.git] / lib / JSON / MaybeXS.pm

diff --git a/lib/JSON/MaybeXS.pm b/lib/JSON/MaybeXS.pm
index 7f8d357..a521d3f 100644 (file)
--- a/lib/JSON/MaybeXS.pm
+++ b/lib/JSON/MaybeXS.pm
@@ -4,7 +4,8 @@ use strict;
 use warnings FATAL => 'all';
 use base qw(Exporter);
 
-our $VERSION = '1.002004';
+our $VERSION = '1.003005';
+$VERSION = eval $VERSION;
 
 sub _choose_json_module {
     return 'Cpanel::JSON::XS' if $INC{'Cpanel/JSON/XS.pm'};
@@ -31,8 +32,11 @@ BEGIN {
 }
 
 our @EXPORT = qw(encode_json decode_json JSON);
-our @EXPORT_OK = qw(is_bool);
-our %EXPORT_TAGS = ( all => [ @EXPORT, @EXPORT_OK ] );
+my @EXPORT_ALL = qw(is_bool);
+our @EXPORT_OK = qw(is_bool to_json from_json);
+our %EXPORT_TAGS = ( all => [ @EXPORT, @EXPORT_ALL ],
+                     legacy => [ @EXPORT, @EXPORT_OK ],
+                   );
 
 sub JSON () { our $JSON_Class }
 
@@ -44,13 +48,53 @@ sub new {
   return $new;
 }
 
-use Safe::Isa;
+use Scalar::Util ();
 
 sub is_bool {
   die 'is_bool is not a method' if $_[1];
 
-  $_[0]->$_isa('JSON::XS::Boolean')
-    or $_[0]->$_isa('JSON::PP::Boolean');
+  Scalar::Util::blessed($_[0])
+    and ($_[0]->isa('JSON::XS::Boolean')
+      or $_[0]->isa('Cpanel::JSON::XS::Boolean')
+      or $_[0]->isa('JSON::PP::Boolean'));
+}
+
+# (mostly) CopyPasta from JSON.pm version 2.90
+use Carp ();
+
+sub from_json ($@) {
+    if ( ref($_[0]) =~ /^JSON/ or $_[0] =~ /^JSON/ ) {
+        Carp::croak "from_json should not be called as a method.";
+    }
+    my $json = JSON()->new;
+
+    if (@_ == 2 and ref $_[1] eq 'HASH') {
+        my $opt  = $_[1];
+        for my $method (keys %$opt) {
+            $json->$method( $opt->{$method} );
+        }
+    }
+
+    return $json->decode( $_[0] );
+}
+
+sub to_json ($@) {
+    if (
+        ref($_[0]) =~ /^JSON/
+        or (@_ > 2 and $_[0] =~ /^JSON/)
+          ) {
+               Carp::croak "to_json should not be called as a method.";
+    }
+    my $json = JSON()->new;
+
+    if (@_ == 2 and ref $_[1] eq 'HASH') {
+        my $opt  = $_[1];
+        for my $method (keys %$opt) {
+            $json->$method( $opt->{$method} );
+        }
+    }
+
+    $json->encode($_[0]);
 }
 
 1;
@@ -97,10 +141,22 @@ To import only some symbols, specify them on the C<use> line:
 
   use JSON::MaybeXS qw(JSON); # JSON constant only
 
-To import all available symbols, use C<:all>:
+To import all available sensible symbols (C<encode_json>, C<decode_json>, and
+C<is_bool>), use C<:all>:
 
   use JSON::MaybeXS ':all';
 
+To import all symbols including those needed by legacy apps that use L<JSON::PP>:
+
+  use JSON::MaybeXS ':legacy';
+
+This imports the C<to_json> and C<from_json> symbols as well as everything in
+C<:all>.  NOTE: This is to support legacy code that makes extensive
+use of C<to_json> and C<from_json> which you are not yet in a position to
+refactor.  DO NOT use this import tag in new code, in order to avoid
+the crawling horrors of getting UTF8 support subtly wrong.  See the
+documentation for L<JSON> for further details.
+
 =head2 encode_json
 
 This is the C<encode_json> function provided by the selected implementation
@@ -115,6 +171,11 @@ module, and takes a string of JSON text to deserialise to a perl data structure.
 
   my $data_structure = decode_json($json_text);
 
+=head2 to_json, from_json
+
+See L<JSON> for details.  These are included to support legacy code
+B<only>.
+
 =head2 JSON
 
 The C<JSON> constant returns the selected implementation module's name for
@@ -162,6 +223,54 @@ To include JSON-aware booleans (C<true>, C<false>) in your data, just do:
     my $true = JSON->true;
     my $false = JSON->false;
 
+=head1 CONVERTING FROM JSON::Any
+
+L<JSON::Any> used to be the favoured compatibility layer above the various
+JSON backends, but over time has grown a lot of extra code to deal with legacy
+backends (e.g. L<JSON::Syck>) that are no longer needed.  This is a rough guide of translating such code:
+
+Change code from:
+
+    use JSON::Any;
+    my $json = JSON::Any->new->objToJson($data);    # or to_json($data), or Dump($data)
+
+to:
+
+    use JSON::MaybeXS;
+    my $json = encode_json($data);
+
+
+Change code from:
+
+    use JSON::Any;
+    my $data = JSON::Any->new->jsonToObj($json);    # or from_json($json), or Load($json)
+
+to:
+
+    use JSON::MaybeXS;
+    my $json = decode_json($data);
+
+=head1 CAVEATS
+
+The C<new()> method in this module is technically a factory, not a
+constructor, because the objects it returns will I<NOT> be blessed into the
+C<JSON::MaybeXS> class.
+
+If you are using an object returned by this module as a Moo(se) attribute,
+this type constraint code:
+
+    is 'json' => ( isa => 'JSON::MaybeXS' );
+
+will I<NOT> do what you expect. Instead, either rely on the C<JSON> class
+constant described above, as so:
+
+    is 'json' => ( isa => JSON::MaybeXS::JSON() );
+
+Alternatively, you can use duck typing:
+
+    use Moose::Util::TypeConstraints 'duck_type';
+    is 'json' => ( isa => Object , duck_type([qw/ encode decode /]));
+
 =head1 AUTHOR
 
 mst - Matt S. Trout (cpan:MSTROUT) <mst@shadowcat.co.uk>
@@ -174,6 +283,8 @@ mst - Matt S. Trout (cpan:MSTROUT) <mst@shadowcat.co.uk>
 
 =item * Karen Etheridge <ether@cpan.org>
 
+=item * Kieren Diment <diment@gmail.com>
+
 =back
 
 =head1 COPYRIGHT