CPAN::Meta(3) User Contributed Perl Documentation CPAN::Meta(3)
NAME
CPAN::Meta - the distribution metadata for a CPAN dist
VERSION
version 2.150010
SYNOPSIS
use v5.10;
use strict;
use warnings;
use CPAN::Meta;
use Module::Load;
my $meta = CPAN::Meta->load_file('META.json');
printf "testing requirements for %s version %s\n",
$meta->name,
$meta->version;
my $prereqs = $meta->effective_prereqs;
for my $phase ( qw/configure runtime build test/ ) {
say "Requirements for $phase:";
my $reqs = $prereqs->requirements_for($phase, "requires");
for my $module ( sort $reqs->required_modules ) {
my $status;
if ( eval { load $module unless $module eq 'perl'; 1 } ) {
my $version = $module eq 'perl' ? $] : $module->VERSION;
$status = $reqs->accepts_module($module, $version)
? "$version ok" : "$version not ok";
} else {
$status = "missing"
};
say " $module ($status)";
}
}
DESCRIPTION
Software distributions released to the CPAN include a META.json or, for
older distributions, META.yml, which describes the distribution, its
contents, and the requirements for building and installing the
distribution. The data structure stored in the META.json file is
described in CPAN::Meta::Spec.
CPAN::Meta provides a simple class to represent this distribution
metadata (or distmeta), along with some helpful methods for
interrogating that data.
The documentation below is only for the methods of the CPAN::Meta
object. For information on the meaning of individual fields, consult
the spec.
METHODS
new
my $meta = CPAN::Meta->new($distmeta_struct, \%options);
Returns a valid CPAN::Meta object or dies if the supplied metadata hash
reference fails to validate. Older-format metadata will be up-
converted to version 2 if they validate against the original stated
specification.
It takes an optional hashref of options. Valid options include:
o lazy_validation -- if true, new will attempt to convert the given
metadata to version 2 before attempting to validate it. This means
than any fixable errors will be handled by CPAN::Meta::Converter
before validation. (Note that this might result in invalid
optional data being silently dropped.) The default is false.
create
my $meta = CPAN::Meta->create($distmeta_struct, \%options);
This is same as "new()", except that "generated_by" and "meta-spec"
fields will be generated if not provided. This means the metadata
structure is assumed to otherwise follow the latest CPAN::Meta::Spec.
load_file
my $meta = CPAN::Meta->load_file($distmeta_file, \%options);
Given a pathname to a file containing metadata, this deserializes the
file according to its file suffix and constructs a new "CPAN::Meta"
object, just like "new()". It will die if the deserialized version
fails to validate against its stated specification version.
It takes the same options as "new()" but "lazy_validation" defaults to
true.
load_yaml_string
my $meta = CPAN::Meta->load_yaml_string($yaml, \%options);
This method returns a new CPAN::Meta object using the first document in
the given YAML string. In other respects it is identical to
"load_file()".
load_json_string
my $meta = CPAN::Meta->load_json_string($json, \%options);
This method returns a new CPAN::Meta object using the structure
represented by the given JSON string. In other respects it is
identical to "load_file()".
load_string
my $meta = CPAN::Meta->load_string($string, \%options);
If you don't know if a string contains YAML or JSON, this method will
use Parse::CPAN::Meta to guess. In other respects it is identical to
"load_file()".
save
$meta->save($distmeta_file, \%options);
Serializes the object as JSON and writes it to the given file. The
only valid option is "version", which defaults to '2'. On Perl 5.8.1 or
later, the file is saved with UTF-8 encoding.
For "version" 2 (or higher), the filename should end in '.json'.
JSON::PP is the default JSON backend. Using another JSON backend
requires JSON 2.5 or later and you must set the $ENV{PERL_JSON_BACKEND}
to a supported alternate backend like JSON::XS.
For "version" less than 2, the filename should end in '.yml'.
CPAN::Meta::Converter is used to generate an older metadata structure,
which is serialized to YAML. CPAN::Meta::YAML is the default YAML
backend. You may set the $ENV{PERL_YAML_BACKEND} to a supported
alternative backend, though this is not recommended due to subtle
incompatibilities between YAML parsers on CPAN.
meta_spec_version
This method returns the version part of the "meta_spec" entry in the
distmeta structure. It is equivalent to:
$meta->meta_spec->{version};
effective_prereqs
my $prereqs = $meta->effective_prereqs;
my $prereqs = $meta->effective_prereqs( \@feature_identifiers );
This method returns a CPAN::Meta::Prereqs object describing all the
prereqs for the distribution. If an arrayref of feature identifiers is
given, the prereqs for the identified features are merged together with
the distribution's core prereqs before the CPAN::Meta::Prereqs object
is returned.
should_index_file
... if $meta->should_index_file( $filename );
This method returns true if the given file should be indexed. It
decides this by checking the "file" and "directory" keys in the
"no_index" property of the distmeta structure. Note that neither the
version format nor "release_status" are considered.
$filename should be given in unix format.
should_index_package
... if $meta->should_index_package( $package );
This method returns true if the given package should be indexed. It
decides this by checking the "package" and "namespace" keys in the
"no_index" property of the distmeta structure. Note that neither the
version format nor "release_status" are considered.
features
my @feature_objects = $meta->features;
This method returns a list of CPAN::Meta::Feature objects, one for each
optional feature described by the distribution's metadata.
feature
my $feature_object = $meta->feature( $identifier );
This method returns a CPAN::Meta::Feature object for the optional
feature with the given identifier. If no feature with that identifier
exists, an exception will be raised.
as_struct
my $copy = $meta->as_struct( \%options );
This method returns a deep copy of the object's metadata as an
unblessed hash reference. It takes an optional hashref of options. If
the hashref contains a "version" argument, the copied metadata will be
converted to the version of the specification and returned. For
example:
my $old_spec = $meta->as_struct( {version => "1.4"} );
as_string
my $string = $meta->as_string( \%options );
This method returns a serialized copy of the object's metadata as a
character string. (The strings are not UTF-8 encoded.) It takes an
optional hashref of options. If the hashref contains a "version"
argument, the copied metadata will be converted to the version of the
specification and returned. For example:
my $string = $meta->as_string( {version => "1.4"} );
For "version" greater than or equal to 2, the string will be serialized
as JSON. For "version" less than 2, the string will be serialized as
YAML. In both cases, the same rules are followed as in the "save()"
method for choosing a serialization backend.
The serialized structure will include a "x_serialization_backend" entry
giving the package and version used to serialize. Any existing key in
the given $meta object will be clobbered.
STRING DATA
The following methods return a single value, which is the value for the
corresponding entry in the distmeta structure. Values should be either
undef or strings.
o abstract
o description
o dynamic_config
o generated_by
o name
o release_status
o version
LIST DATA
These methods return lists of string values, which might be represented
in the distmeta structure as arrayrefs or scalars:
o authors
o keywords
o licenses
The "authors" and "licenses" methods may also be called as "author" and
"license", respectively, to match the field name in the distmeta
structure.
MAP DATA
These readers return hashrefs of arbitrary unblessed data structures,
each described more fully in the specification:
o meta_spec
o resources
o provides
o no_index
o prereqs
o optional_features
CUSTOM DATA
A list of custom keys are available from the "custom_keys" method and
particular keys may be retrieved with the "custom" method.
say $meta->custom($_) for $meta->custom_keys;
If a custom key refers to a data structure, a deep clone is returned.
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.
SEE ALSO
o CPAN::Meta::Converter
o CPAN::Meta::Validator
SUPPORT
Bugs / Feature Requests
Please report any bugs or feature requests through the issue tracker at
<https://github.com/Perl-Toolchain-Gang/CPAN-Meta/issues>. You will be
notified automatically of any progress on your issue.
Source Code
This is open source software. The code repository is available for
public review and contribution under the terms of the license.
<https://github.com/Perl-Toolchain-Gang/CPAN-Meta>
git clone https://github.com/Perl-Toolchain-Gang/CPAN-Meta.git
AUTHORS
o David Golden <dagolden AT cpan.org>
o Ricardo Signes <rjbs AT cpan.org>
o Adam Kennedy <adamk AT cpan.org>
CONTRIBUTORS
o Ansgar Burchardt <ansgar AT cpan.org>
o Avar Arnfjord Bjarmason <avar AT cpan.org>
o Benjamin Noggle <agwind AT users.com>
o Christopher J. Madsen <cjm AT cpan.org>
o Chuck Adams <cja987 AT gmail.com>
o Cory G Watson <gphat AT cpan.org>
o Damyan Ivanov <dam AT cpan.org>
o David Golden <xdg AT xdg.me>
o Eric Wilhelm <ewilhelm AT cpan.org>
o Graham Knop <haarg AT haarg.org>
o Gregor Hermann <gregoa AT debian.org>
o Karen Etheridge <ether AT cpan.org>
o Kenichi Ishigaki <ishigaki AT cpan.org>
o Kent Fredric <kentfredric AT gmail.com>
o Ken Williams <kwilliams AT cpan.org>
o Lars Dieckow <daxim AT cpan.org>
o Leon Timmermans <leont AT cpan.org>
o majensen <maj AT fortinbras.us>
o Mark Fowler <markf AT cpan.org>
o Matt S Trout <mst AT shadowcat.uk>
o Michael G. Schwern <mschwern AT cpan.org>
o Mohammad S Anwar <mohammad.anwar AT yahoo.com>
o mohawk2 <mohawk2 AT users.com>
o moznion <moznion AT gmail.com>
o Niko Tyni <ntyni AT debian.org>
o Olaf Alders <olaf AT wundersolutions.com>
o Olivier Mengue <dolmen AT cpan.org>
o Randy Sims <randys AT thepierianspring.org>
o Tomohiro Hosaka <bokutin AT bokut.in>
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.
perl v5.26.3 2016-08-18 CPAN::Meta(3)