Manpages - CPAN_Meta.3perl
Table of Contents
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:
- lazy_validation Ω- 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.
- abstract
- description
- dynamic_config
- generated_by
- name
- release_status
- version
LIST DATA
These methods return lists of string values, which might be represented in the distmeta structure as arrayrefs or scalars:
- authors
- keywords
- 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:
- meta_spec
- resources
- provides
- no_index
- prereqs
- 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
- CPAN::Meta::Converter
- 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
- David Golden <dagolden@cpan.org>
- Ricardo Signes <rjbs@cpan.org>
- Adam Kennedy <adamk@cpan.org>
CONTRIBUTORS
- Ansgar Burchardt <ansgar@cpan.org>
- Avar Arnfjord Bjarmason <avar@cpan.org>
- Benjamin Noggle <agwind@users.noreply.github.com>
- Christopher J. Madsen <cjm@cpan.org>
- Chuck Adams <cja987@gmail.com>
- Cory G Watson <gphat@cpan.org>
- Damyan Ivanov <dam@cpan.org>
- David Golden <xdg@xdg.me>
- Eric Wilhelm <ewilhelm@cpan.org>
- Graham Knop <haarg@haarg.org>
- Gregor Hermann <gregoa@debian.org>
- Karen Etheridge <ether@cpan.org>
- Kenichi Ishigaki <ishigaki@cpan.org>
- Kent Fredric <kentfredric@gmail.com>
- Ken Williams <kwilliams@cpan.org>
- Lars Dieckow <daxim@cpan.org>
- Leon Timmermans <leont@cpan.org>
- majensen <maj@fortinbras.us>
- Mark Fowler <markf@cpan.org>
- Matt S Trout <mst@shadowcat.co.uk>
- Michael G. Schwern <mschwern@cpan.org>
- Mohammad S Anwar <mohammad.anwar@yahoo.com>
- mohawk2 <mohawk2@users.noreply.github.com>
- moznion <moznion@gmail.com>
- Niko Tyni <ntyni@debian.org>
- Olaf Alders <olaf@wundersolutions.com>
- Olivier Mengue <dolmen@cpan.org>
- Randy Sims <randys@thepierianspring.org>
- Tomohiro Hosaka <bokutin@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.