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.