=head1 NAME

Sub::HandlesVia::HandlerLibrary::Code - library of code-related methods

=head1 SYNOPSIS

  package My::Class {
    use Moo;
    use Sub::HandlesVia;
    use Types::Standard 'CodeRef';
    has attr => (
      is => 'rwp',
      isa => CodeRef,
      handles_via => 'Code',
      handles => {
        'my_execute' => 'execute',
        'my_execute_list' => 'execute_list',
        'my_execute_method' => 'execute_method',
        'my_execute_method_list' => 'execute_method_list',
        'my_execute_method_scalar' => 'execute_method_scalar',
        'my_execute_method_void' => 'execute_method_void',
        'my_execute_scalar' => 'execute_scalar',
        'my_execute_void' => 'execute_void',
      },
    );
  }

=head1 DESCRIPTION

This is a library of methods for L<Sub::HandlesVia>.

=head1 DELEGATABLE METHODS

=head2 C<< execute( @args ) >>

Calls the coderef, passing it any arguments.

  my $coderef = sub { 'code' };
  my $object  = My::Class->new( attr => $coderef );
  
  # Calls: $coderef->( 1, 2, 3 )
  $object->my_execute( 1, 2, 3 );

=head2 C<< execute_list( @args ) >>

Calls the coderef, passing it any arguments, and forcing list context. If called in scalar context, returns an arrayref.

  my $context;
  my $coderef = sub { $context = wantarray(); 'code' };
  my $object  = My::Class->new( attr => $coderef );
  
  # Calls: $coderef->( 1, 2, 3 )
  my $result = $object->my_execute_list( 1, 2, 3 );
  
  say Dumper( $result );  ## ==> [ 'code' ]
  say $context;           ## ==> true

=head2 C<< execute_method( @args ) >>

Calls the coderef as if it were a method, passing any arguments.

  my $coderef = sub { 'code' };
  my $object  = My::Class->new( attr => $coderef );
  
  # Calls: $coderef->( $object, 1, 2, 3 )
  $object->my_execute_method( 1, 2, 3 );

=head2 C<< execute_method_list( @args ) >>

Calls the coderef as if it were a method, passing any arguments, and forcing list context. If called in scalar context, returns an arrayref.

  my $context;
  my $coderef = sub { $context = wantarray(); 'code' };
  my $object  = My::Class->new( attr => $coderef );
  
  # Calls: $coderef->( $object, 1, 2, 3 )
  my $result = $object->my_execute_method_list( 1, 2, 3 );
  
  say Dumper( $result );  ## ==> [ 'code' ]
  say $context;           ## ==> true

=head2 C<< execute_method_scalar( @args ) >>

Calls the coderef as if it were a method, passing any arguments, and forcing scalar context.

  my $context;
  my $coderef = sub { $context = wantarray(); 'code' };
  my $object  = My::Class->new( attr => $coderef );
  
  # Calls: $coderef->( $object, 1, 2, 3 )
  my $result = $object->my_execute_method_scalar( 1, 2, 3 );
  
  say $result;  ## ==> 'code'
  say $context; ## ==> false

=head2 C<< execute_method_void( @args ) >>

Calls the coderef as if it were a method, passing any arguments, and forcing void context. Returns undef.

  my $context;
  my $coderef = sub { $context = wantarray(); 'code' };
  my $object  = My::Class->new( attr => $coderef );
  
  # Calls: $coderef->( $object, 1, 2, 3 )
  my $result = $object->my_execute_method_void( 1, 2, 3 );
  
  say $result;  ## ==> undef
  say $context; ## ==> undef

=head2 C<< execute_scalar( @args ) >>

Calls the coderef, passing it any arguments, and forcing scalar context.

  my $context;
  my $coderef = sub { $context = wantarray(); 'code' };
  my $object  = My::Class->new( attr => $coderef );
  
  # Calls: $coderef->( 1, 2, 3 )
  my $result = $object->my_execute_scalar( 1, 2, 3 );
  
  say $result;  ## ==> 'code'
  say $context; ## ==> false

=head2 C<< execute_void( @args ) >>

Calls the coderef, passing it any arguments, and forcing void context. Returns undef.

  my $context;
  my $coderef = sub { $context = wantarray(); 'code' };
  my $object  = My::Class->new( attr => $coderef );
  
  # Calls: $coderef->( 1, 2, 3 )
  my $result = $object->my_execute_void( 1, 2, 3 );
  
  say $result;  ## ==> undef
  say $context; ## ==> undef

=head1 EXTENDED EXAMPLES

=head2 Using execute_method

The execute_method handler allows a class to effectively provide certain methods which can be overridden by parameters in the constructor.

  use strict;
  use warnings;
  use Data::Dumper;
  
  package My::Processor {
    use Moo;
    use Sub::HandlesVia;
    use Types::Standard qw( Str CodeRef );
    
    has name => (
      is => 'ro',
      isa => Str,
      default => 'Main Process',
    );
    
    my $NULL_CODEREF = sub {};
    
    has _debug => (
      is => 'ro',
      isa => CodeRef,
      handles_via => 'Code',
      handles => { debug => 'execute_method' },
      default => sub { $NULL_CODEREF },
      init_arg => 'debug',
    );
    
    sub _do_stuff {
      my $self = shift;
      $self->debug( 'continuing process' );
      return;
    }
    
    sub run_process {
      my $self = shift;
      $self->debug( 'starting process' );
      $self->_do_stuff;
      $self->debug( 'ending process' );
    }
  }
  
  my $p1 = My::Processor->new( name => 'First Process' );
  $p1->run_process; # no output
  
  my @got;
  my $p2 = My::Processor->new(
    name => 'Second Process',
    debug => sub {
      my ( $processor, $message ) = @_;
      push @got, sprintf( '%s: %s', $processor->name, $message );
    },
  );
  $p2->run_process; # logged output
  
  my @expected = (
    'Second Process: starting process',
    'Second Process: continuing process',
    'Second Process: ending process',
  );
  say Dumper( \@got ); ## ==> \@expected

=head1 BUGS

Please report any bugs to
L<https://github.com/tobyink/p5-sub-handlesvia/issues>.

=head1 SEE ALSO

L<Sub::HandlesVia>.

=head1 AUTHOR

Toby Inkster E<lt>tobyink@cpan.orgE<gt>.

=head1 COPYRIGHT AND LICENCE

This software is copyright (c) 2020, 2022 by Toby Inkster.

This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.

=head1 DISCLAIMER OF WARRANTIES

THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.

