package CGI::Application::Plugin::JSON; use warnings; use strict; use JSON qw(objToJson jsonToObj); use base 'Exporter'; our @EXPORT_OK = qw( to_json from_json json_header json_body json_callback add_json_header clear_json_header json_header_string json_header_value ); our %EXPORT_TAGS = ( all => \@EXPORT_OK ); =head1 NAME CGI::Application::Plugin::JSON - easy manipulation of JSON headers =cut our $VERSION = '0.3'; =head1 SYNOPSIS use CGI::Application::Plugin::JSON ':all'; # add_json_header() is cumulative $self->add_json_header( foo => 'Lorem ipsum...'); $self->add_json_header( bar => [ 0, 2, 3, 4 ] ); $self->add_json_header( baz => { stuff => 1, more_stuff => 2 } ); # json_header() is not cumulative $self->json_header( foo => 'Lorem ipsum...'); # in case we're printing our own headers print "X-JSON: " . $self->json_header_string(); # clear out everything in the outgoing JSON headers $self->clear_json_header(); # or send the JSON in the document body $self->json_body( { foo => 'Lorem ipsum', bar => [ 0, 2, 3 ] } ); # send the JSON back in the document body, but execute it using a Javascript callback $self->json_callback('alert', { foo => 'Lorem ipsum', bar => [ 0, 2, 3 ] } ); =head1 DESCRIPTION When communicating with client-side JavaScript, it is common to send data in C<X-JSON> HTTP headers or through the document body as content-type C<text/x-json>. This plugin adds a couple of convenience methods to make that just a little bit easier. =head1 HEADER METHODS =head2 json_header This method takes name-value pairs and sets them to be used in the outgoing JSON. It is not cummulative and works similarly to C<header_props>. Use it only if you have all of the values up front. In most cases L<add_json_header> is probably what you want. # only the 2nd call will actually set data that will be sent $self->json_header( foo => 'Lorem ipsum...'); $self->json_header( bar => [ 0, 2, 3, 4 ] ); =cut sub json_header { my ($self, %data) = @_; my $private = $self->param('__CAP_JSON') || {}; $private->{header} = \%data; $self->param('__CAP_JSON' => $private); return ' '; # so it can be used as the return value from an rm } =head2 add_json_header This method takes name-value pairs and sets them to be used in the outgoing JSON. It is cummulative and works similarly to C<header_add>; meaning multiple calls will add to the hash of outgoing values. # both 'foo' and 'bar' will exist in the hash sent out $self->json_header( foo => 'Lorem ipsum...'); $self->json_header( bar => [ 0, 2, 3, 4 ] ); =cut sub add_json_header { my ($self, %data) = @_; my $private = $self->param('__CAP_JSON') || {}; $private->{header} ||= {}; $private->{header} = { %{$private->{header}}, %data }; $self->param('__CAP_JSON' => $private); return ' '; # so it can be used as the return value from an rm } =head2 clear_json_header This method will remove anything that was previously set by both L<json_header> and L<add_json_header>. This means that no C<X-JSON> header will be sent. =cut sub clear_json_header { my $self = shift; my $private = $self->param('__CAP_JSON') || {}; delete $private->{header}; $self->param('__CAP_JSON' => $private); } =head2 json_header_string This method will create the actual HTTP header string that will be sent to the browser. This plugin uses it internally to send the header, but it might be useful to use directly if you are printing your own HTTP headers (using a C<header_type> of C<none>). $self->header_type('none'); print $self->json_header_string(); =cut sub json_header_string { my $self = shift; my $private = $self->param('__CAP_JSON') || {}; return $self->to_json($private->{header} || {}); } =head2 json_header_value This method will return the values being sent in the JSON header. If you pass in the key of the value you want, you will get just that value. Else all name-value pairs will be returned. my $value = $self->json_header_value('foo'); my %values = $self->json_header_value(); =cut sub json_header_value { my ($self, $key) = @_; my $private = $self->param('__CAP_JSON') || {}; if( defined $private->{header} ) { if( defined $key ) { return $private->{header}->{$key}; } else { return %{$private->{header}}; } } else { return; } } =head1 BODY METHODS =head2 json_body This method will take the given Perl structure, turn it into JSON, set the appropriate content-type, and then return the JSON. return $self->json_body({ foo => 'stuff', bar => [0,1,2,3]} ); =cut sub json_body { my ($self, $data) = @_; my $private = $self->param('__CAP_JSON') || {}; $private->{json_body} = 1; $self->param(__CAP_JSON => $private); return $self->to_json($data); } =head2 json_callback This method will take the given Perl structure, turn it into JSON, set the appropriate content-type, and then return a Javascript snippet where the given callback is called with the resulting JSON. return $self->json_callback('alert', { foo => 'stuff', bar => [0,1,2,3]} ); # would result in something like the following being sent to the client alert({ foo => 'stuff', bar => [0,1,2,3]}); =cut sub json_callback { my ($self, $callback, $data) = @_; my $private = $self->param('__CAP_JSON') || {}; $private->{json_callback} = 1; $self->param(__CAP_JSON => $private); return $callback . '(' . $self->to_json($data) . ')'; } =head1 MISC METHODS =head2 to_json This method is just a convenient wrapper around L<JSON>'s C<objToJson>. =cut sub to_json { my ($self, $data) = @_; return objToJson($data); } =head2 from_json This method is just a convenient wrapper around L<JSON>'s C<jsonToObj>. =cut sub from_json { my ($self, $data) = @_; return jsonToObj($data); } sub import { my $caller = scalar(caller); $caller->add_callback( postrun => \&_send_headers ); __PACKAGE__->export_to_level(1, @_); } sub _send_headers { my $self = shift; my $private = $self->param('__CAP_JSON') || {}; if( defined $private->{header} ) { $self->header_add( '-x-json' => $self->json_header_string ); } if( defined $private->{json_body} ) { $self->header_add('-type' => 'text/x-json'); } elsif ( defined $private->{json_callback} ) { $self->header_add('-type' => 'text/javascript'); } } 1; __END__ =head1 AUTHOR Michael Peters, C<< <mpeters@plusthree.com> >> =head1 BUGS Please report any bugs or feature requests to C<bug-cgi-application-plugin-viewsource@rt.cpan.org>, or through the web interface at L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=CGI-Application-Plugin-JSON>. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes. =head1 COPYRIGHT & LICENSE Copyright 2006 Michael Peters, All Rights Reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.