NAME

       CPAN::Meta::Converter - Convert CPAN distribution metadata structures

VERSION

       version 2.150010

SYNOPSIS

         my $struct = decode_json_file('META.json');

         my $cmc = CPAN::Meta::Converter->new( $struct );

         my $new_struct = $cmc->convert( version => "2" );

DESCRIPTION

       This module converts CPAN Meta structures from one form to another.  The primary use is to
       convert older structures to the most modern version of the specification, but other
       transformations may be implemented in the future as needed.  (E.g. stripping all custom
       fields or stripping all optional fields.)

METHODS

   new
         my $cmc = CPAN::Meta::Converter->new( $struct );

       The constructor should be passed a valid metadata structure but invalid structures are
       accepted.  If no meta-spec version is provided, version 1.0 will be assumed.

       Optionally, you can provide a "default_version" argument after $struct:

         my $cmc = CPAN::Meta::Converter->new( $struct, default_version => "1.4" );

       This is only needed when converting a metadata fragment that does not include a
       "meta-spec" field.

   convert
         my $new_struct = $cmc->convert( version => "2" );

       Returns a new hash reference with the metadata converted to a different form.  "convert"
       will die if any conversion/standardization still results in an invalid structure.

       Valid parameters include:

       •   "version" -- Indicates the desired specification version (e.g. "1.0", "1.1" ... "1.4",
           "2").  Defaults to the latest version of the CPAN Meta Spec.

       Conversion proceeds through each version in turn.  For example, a version 1.2 structure
       might be converted to 1.3 then 1.4 then finally to version 2. The conversion process
       attempts to clean-up simple errors and standardize data.  For example, if "author" is
       given as a scalar, it will converted to an array reference containing the item.
       (Converting a structure to its own version will also clean-up and standardize.)

       When data are cleaned and standardized, missing or invalid fields will be replaced with
       sensible defaults when possible.  This may be lossy or imprecise.  For example, some badly
       structured META.yml files on CPAN have prerequisite modules listed as both keys and
       values:

         requires => { 'Foo::Bar' => 'Bam::Baz' }

       These would be split and each converted to a prerequisite with a minimum version of zero.

       When some mandatory fields are missing or invalid, the conversion will attempt to provide
       a sensible default or will fill them with a value of 'unknown'.  For example a missing or
       unrecognized "license" field will result in a "license" field of 'unknown'.  Fields that
       may get an 'unknown' include:

       •   abstract

       •   author

       •   license

   upgrade_fragment
         my $new_struct = $cmc->upgrade_fragment;

       Returns a new hash reference with the metadata converted to the latest version of the CPAN
       Meta Spec.  No validation is done on the result -- you must validate after merging
       fragments into a complete metadata document.

       Available since version 2.141170.

BUGS

       Please report any bugs or feature using the CPAN Request Tracker.  Bugs can be submitted
       through the web interface at <http://rt.cpan.org/Dist/Display.html?Queue=CPAN-Meta>

       When submitting a bug or request, please include a test-file or a patch to an existing
       test-file that illustrates the bug or desired feature.

AUTHORS

       •   David Golden <dagolden@cpan.org>

       •   Ricardo Signes <rjbs@cpan.org>

       •   Adam Kennedy <adamk@cpan.org>

COPYRIGHT AND LICENSE

       This software is copyright (c) 2010 by David Golden, Ricardo Signes, Adam Kennedy and
       Contributors.

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