NAME

Pod::Constants - Include constants from POD

SYNOPSIS

use vars qw($myvar $VERSION @myarray $html %myhash);

use Pod::Constants -trim => 1,
    'Pod Section Name' => \$myvar,
    'Version' => sub { eval },
    'Some list' => \@myarray,
    html => \$html,
    'Some hash' => \%myhash;

=head2 Pod Section Name

This string will be loaded into $myvar

=head2 Version

# This is an example of using a closure.  $_ is set to the
# contents of the paragraph.  In this example, "eval" is
# used to execute this code at run time.
$VERSION = 0.11;

=head2 Some list

Each line from this section of the file
will be placed into a seperate array element.
For example, this is $myarray[2].

=head2 Some hash

This text will not go into the hash, because
it doesn't look like a definition list.
    key1 => Some value (this will go into the hash)
    var2 => Some Other value (so will this)
    wtf = This won't make it in.

=head2 %myhash's value after the above:

   ( key1 => "Some value (this will go into the hash)",
     var2 => "Some Other value (so will this)"          )

=begin html <p>This text will be in $html</p>

=cut

DESCRIPTION

This module allows you to specify those constants that should be documented in your POD, and pull them out a run time in a fairly arbitrary fashion.

Pod::Constants uses Pod::Parser to do the parsing of the source file. It has to open the source file it is called from, and does so directly either by lookup in %INC or by assuming it is $0 if the caller is "main" (or it can't find %INC{caller()})

ARBITARY DECISIONS

I have made this code only allow the "Pod Section Name" to match `headN', `item', `for' and `begin' POD sections. If you have a good reason why you think it should match other POD sections, drop me a line and if I'm convinced I'll put it in the standard version.

For `for' and `begin' sections, only the first word is counted as being a part of the specifier, as opposed to `headN' and `item', where the entire rest of the line counts.

CLOSURES AS DESTINATIONS

If the given value is a ref CODE, then that function is called, with $_ set to the value of the paragraph. This can be very useful for applying your own custom mutations to the POD to change it from human readable text into something your program can use.

After I added this function, I just kept on thinking of cool uses for it. The nice, succinct code you can make with it is one of Pod::Constant's strongest features.

Below are some examples.

EXAMPLES

Module Makefile.PL maintenance

Tired of keeping those module Makefile.PL's up to date?

Example Makefile.PL

eval "use Pod::Constants";
($Pod::Constants::VERSION >= 0.11)
    or die <<EOF
####
####  ERROR: This module requires Pod::Constants 0.11 or
####  higher to be installed.
####
EOF

my ($VERSION, $NAME, $PREREQ_PM, $ABSTRACT, $AUTHOR);
Pod::Constants::import_from_file 
    (
     'MyTestModule.pm', -trim => 1,
     'NAME' => sub { $ABSTRACT=$_; ($NAME) = m/(\S+)/ },
     'MODULE RELEASE' => sub { ($VERSION) = m/(\d+\.\d+)/ },
     'DEPENDANCIES' => ($PREREQ_PM = { }),
     'AUTHOR' => \$AUTHOR,
    );

WriteMakefile
    (
     'NAME'		=> $NAME,
     'PREREQ_PM'        => $PREREQ_PM,
     'VERSION'          => $VERSION,
     ($] >= 5.005 ?    ## Add these new keywords supported since 5.005
      (ABSTRACT         => $ABSTRACT,
       AUTHOR           => $AUTHOR) : ()),
    );

Corresponding Module

=head1 NAME

MyTestModule - Demonstrate Pod::Constant's Makefile.PL usefulness

=head2 MODULE RELEASE

This is release 1.05 of this module.

=head2 DEPENDANCIES

The following modules are required to make this module:

   Some::Module => 0.02

=head2 AUTHOR

Ima Twat <ima@twat.name>

=cut

use vars qw($VERSION);
use Pod::Constants -trim => 1,
    'MODULE RELEASE' => sub { ($VERSION) = m/(\d+\.\d+) or die };

AUTHOR

Sam Vilain, <perl@snowcra.sh>

BUGS/TODO

I keep thinking it would be nice to be able to import an =item list into an array or something, eg for a program argument list. But I'm not too sure how it would be all that useful in practice; you'd end up putting the function names for callbacks in the pod or something (perhaps not all that bad).

Would this be useful?

Pod::Constants::import(Foo::SECTION => \$myvar);