inc::latest

Section: User Contributed Perl Documentation (3pm)
Updated: 2016-07-24
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NAME

inc::latest - use modules bundled in inc/ if they are newer than installed ones  

SYNOPSIS

  # in Build.PL
  use inc::latest 'Module::Build';

 

DESCRIPTION

The "inc::latest" module helps bootstrap configure-time dependencies for CPAN distributions. These dependencies get bundled into the "inc" directory within a distribution and are used by Build.PL (or Makefile.PL).

Arguments to "inc::latest" are module names that are checked against both the current @INC array and against specially-named directories in "inc". If the bundled version is newer than the installed one (or the module isn't installed, then, the bundled directory is added to the start of <@INC> and the module is loaded from there.

There are actually two variations of "inc::latest" --- one for authors and one for the "inc" directory. For distribution authors, the "inc::latest" installed in the system will record modules loaded via "inc::latest" and can be used to create the bundled files in "inc", including writing the second variation as "inc/latest.pm".

This second "inc::latest" is the one that is loaded in a distribution being installed (e.g. from Build.PL). This bundled "inc::latest" is the one that determines which module to load.  

Special notes on bundling

The "inc::latest" module creates bundled directories based on the packlist file of an installed distribution. Even though "inc::latest" takes module name arguments, it is better to think of it as bundling and making available entire distributions. When a module is loaded through "inc::latest", it looks in all bundled distributions in "inc/" for a newer module than can be found in the existing @INC array.

Thus, the module-name provided should usually be the ``top-level'' module name of a distribution, though this is not strictly required. For example, Module::Build has a number of heuristics to map module names to packlists, allowing users to do things like this:

  use inc::latest 'Devel::AssertOS::Unix';

even though Devel::AssertOS::Unix is contained within the Devel-CheckOS distribution.

At the current time, packlists are required. Thus, bundling dual-core modules may require a 'forced install' over versions in the latest version of perl in order to create the necessary packlist for bundling.  

USAGE

When calling "use", the bundled "inc::latest" takes a single module name and optional arguments to pass to that module's own import method.

  use 'inc::latest' 'Foo::Bar' qw/foo bar baz/;

 

Author-mode

You are in author-mode inc::latest if any of the Author-mode methods are available. For example:

  if ( inc::latest->can('write') ) {
    inc::latest->write('inc');
  }

loaded_modules()
  my @list = inc::latest->loaded_modules;

This takes no arguments and always returns a list of module names requested for loading via ``use inc::latest 'MODULE''', regardless of whether the load was successful or not.

write()
  inc::latest->write( 'inc' );

This writes the bundled version of inc::latest to the directory name given as an argument. It almost all cases, it should be '"inc"'.

bundle_module()
  for my $mod ( inc::latest->loaded_modules ) {
    inc::latest->bundle_module($mod, $dir);
  }

If $mod corresponds to a packlist, then this function creates a specially-named directory in $dir and copies all .pm files from the modlist to the new directory (which almost always should just be 'inc'). For example, if Foo::Bar is the name of the module, and $dir is 'inc', then the directory would be 'inc/inc_Foo-Bar' and contain files like this:

  inc/inc_Foo-Bar/Foo/Bar.pm

Currently, $mod must have a packlist. If this is not the case (e.g. for a dual-core module), then the bundling will fail. You may be able to create a packlist by forced installing the module on top of the version that came with core Perl.

 

As bundled in inc/

All methods are private. Only the "import" method is public.  

AUTHOR

Eric Wilhelm <ewilhelm@cpan.org>, David Golden <dagolden@cpan.org>  

COPYRIGHT

Copyright (c) 2009 by Eric Wilhelm and David Golden

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

SEE ALSO

Module::Build


 

Index

NAME
SYNOPSIS
DESCRIPTION
Special notes on bundling
USAGE
Author-mode
As bundled in inc/
AUTHOR
COPYRIGHT
SEE ALSO