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package Filter::EOF;
=head1 NAME
Filter::EOF - Run a callback after a file has been compiled
=cut
use strict;
=head1 VERSION
0.04
=cut
our $VERSION = 0.04;
=head1 SYNOPSIS
package MyPackage;
use warnings;
use strict;
use Filter::EOF;
sub import {
my ($class, @args) = @_;
my $caller = scalar caller;
# set the COMPILE_TIME package var to a false value
# when the file was compiled
Filter::EOF->on_eof_call(sub {
no strict 'refs';
${ $caller . '::COMPILE_TIME' } = 0;
});
# set the COMPILE_TIME package var to a true value when
# we start compiling it.
{ no strict 'refs';
${ $caller . '::COMPILE_TIME' } = 1;
}
}
1;
...
package MyUsingPackage;
use warnings;
use strict;
our $COMPILE_TIME;
use MyPackage;
# prints 'yes'
BEGIN { print +( $COMPILE_TIME ? 'yes' : 'no' ), "\n" }
# prints 'no'
print +( $COMPILE_TIME ? 'yes' : 'no' ), "\n";
1;
=head1 DESCRIPTION
This module utilises Perl's source filters to provide you with a
mechanism to run some code after a file using your module has been
processed.
=cut
use Carp;
=head1 METHODS
=head2 C<import( @functions )>
Currently, only a function equivalent of the C<on_eof_call> method
is provided for export.
use Filter::EOF qw( on_eof_call );
sub import {
my ($class) = @_;
...
on_eof_call { ... };
}
...
=cut
my %Export = (
on_eof_call => sub { my $class = shift; sub (&) { $class->on_eof_call(@_) } },
);
sub import {
my ($class, @names) = @_;
for my $name (@names) {
Carp::croak "Unknown function '$name'" unless exists $Export{ $name };
no strict 'refs';
*{ scalar(caller) . '::' . $name } = $Export{ $name }->($class);
}
return 1;
}
=head2 C<on_eof_call( $code_ref )>
Call this method in your own C<import> method to register a code
reference that should be called when the file C<use>ing yours was
compiled.
The code reference will get a scalar reference as first argument
to an empty string. if you change this string to something else,
it will be appended at the end of the source.
# call C<some_function()> after runtime.
Filter->on_eof_call(sub {
my $append = shift;
$$append .= '; some_function(); 1;';
});
=cut
sub on_eof_call {
my ($class, $code) = @_;
my $past_eof;
filter_add( sub {
my $status = filter_read;
return $status if $past_eof;
if ($status == 0) {
$code->(\$_);
$status = 1;
$past_eof = 1;
}
return $status;
});
}
=head1 EXPORTS
=head2 on_eof_call
You can optionally import the C<on_eof_call> function into your namespace.
=head1 EXAMPLES
You can find the example mentioned in L</SYNOPSIS> in the distribution
directory C<examples/synopsis/>.
=head1 SEE ALSO
L<Filter::Call::Util>,
L<Exporter/Exporting without using Exporter's import method>
=head1 AUTHOR AND COPYRIGHT
Robert 'phaylon' Sedlacek - C<E<lt>rs@474.atE<gt>>. Many thanks to
Matt S Trout for the idea and inspirations on this module.
=head1 LICENSE
This program is free software; you can redistribute it and/or modify
it under the same terms as perl itself.
=cut
1;