#============================================================= -*-Perl-*-
#
# Template::Plugin::Scalar
#
# DESCRIPTION
# Template Toolkit plugin module which allows you to call object methods
# in scalar context.
#
# AUTHOR
# Andy Wardley <abw@wardley.org>
#
# COPYRIGHT
# Copyright (C) 2008-2022 Andy Wardley. All Rights Reserved.
#
# This module is free software; you can redistribute it and/or
# modify it under the same terms as Perl itself.
#
#============================================================================
package Template::Plugin::Scalar;
use base 'Template::Plugin';
use strict;
use warnings;
use Template::Exception;
use Scalar::Util qw();
our $VERSION = '3.100';
our $MONAD = 'Template::Monad::Scalar';
our $EXCEPTION = 'Template::Exception';
our $AUTOLOAD;
sub load {
my $class = shift;
my $context = shift;
# define .scalar vmethods for hash and list objects
$context->define_vmethod( hash => scalar => \&scalar_monad );
$context->define_vmethod( list => scalar => \&scalar_monad );
return $class;
}
sub scalar_monad {
# create a .scalar monad which wraps the hash- or list-based object
# and delegates any method calls back to it, calling them in scalar
# context, e.g. foo.scalar.bar becomes $MONAD->new($foo)->bar and
# the monad calls $foo->bar in scalar context
$MONAD->new(shift);
}
sub new {
my ($class, $context, @args) = @_;
# create a scalar plugin object which will lookup a variable subroutine
# and call it. e.g. scalar.foo results in a call to foo() in scalar context
my $self = bless {
_CONTEXT => $context,
}, $class;
return $self;
}
sub AUTOLOAD {
my $self = shift;
my $item = $AUTOLOAD;
$item =~ s/.*:://;
return if $item eq 'DESTROY';
# lookup the named values
my $stash = $self->{ _CONTEXT }->stash;
my $value = $stash->{ $item };
if (! defined $value) {
die $EXCEPTION->new( scalar => "undefined value for scalar call: $item" );
}
elsif (ref $value eq 'CODE') {
$value = $value->(@_);
}
return $value;
}
package Template::Monad::Scalar;
our $EXCEPTION = 'Template::Exception';
our $AUTOLOAD;
sub new {
my ($class, $this) = @_;
bless \$this, $class;
}
sub AUTOLOAD {
my $self = shift;
my $this = $$self;
my $item = $AUTOLOAD;
$item =~ s/.*:://;
return if $item eq 'DESTROY';
my $method;
if (Scalar::Util::blessed($this)) {
# lookup the method...
$method = $this->can($item);
}
else {
die $EXCEPTION->new( scalar => "invalid object method: $item" );
}
# ...and call it in scalar context
my $result = $method->($this, @_);
return $result;
}
1;
__END__
=head1 NAME
Template::Plugin::Scalar - call object methods in scalar context
=head1 SYNOPSIS
[% USE scalar %]
# TT2 calls object methods in array context by default
[% object.method %]
# force it to use scalar context
[% object.scalar.method %]
# also works with subroutine references
[% scalar.my_sub_ref %]
=head1 DESCRIPTION
The Template Toolkit calls user-defined subroutines and object methods
using Perl's array context by default. This plugin module provides a way
for you to call subroutines and methods in scalar context.
=head1 AUTHOR
Andy Wardley E<lt>abw@wardley.orgE<gt> L<http://wardley.org/>
=head1 COPYRIGHT
Copyright (C) 2008-2022 Andy Wardley. All Rights Reserved.
This module is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.
=head1 SEE ALSO
L<Template::Plugin>
=cut
# Local Variables:
# mode: perl
# perl-indent-level: 4
# indent-tabs-mode: nil
# End:
#
# vim: expandtab shiftwidth=4:
|