man Parse::CPAN::Meta (3): Parse META.yml and META.json CPAN metadata files

VERSION

version 1.4414

SYNOPSIS

#############################################
# In your file

---
name: My-Distribution
version: 1.23
resources:
homepage: "http://example.com/dist/My-Distribution"

#############################################
# In your program

use Parse::CPAN::Meta;

my $distmeta = Parse::CPAN::Meta->load_file('META.yml');

# Reading properties
my $name = $distmeta->{name};
my $version = $distmeta->{version};
my $homepage = $distmeta->{resources}{homepage};

DESCRIPTION

Parse::CPAN::Meta is a parser for META.json and META.yml files, using JSON::PP and/or CPAN::Meta::YAML.

Parse::CPAN::Meta provides three methods: "load_file", "load_json_string", and "load_yaml_string". These will read and deserialize CPAN metafiles, and are described below in detail.

Parse::CPAN::Meta provides a legacy API of only two functions, based on the YAML functions of the same name. Wherever possible, identical calling semantics are used. These may only be used with YAML sources.

All error reporting is done with exceptions (die'ing).

Note that META files are expected to be in UTF-8 encoding, only. When converted string data, it must first be decoded from UTF-8.

METHODS

load_file

  my $metadata_structure = Parse::CPAN::Meta->load_file('META.json');
  my $metadata_structure = Parse::CPAN::Meta->load_file('META.yml');

This method will read the named file and deserialize it to a data structure, determining whether it should be JSON or YAML based on the filename. The file will be read using the ``:utf8'' IO layer.

load_yaml_string

  my $metadata_structure = Parse::CPAN::Meta->load_yaml_string($yaml_string);

This method deserializes the given string of YAML and returns the first document in it. (CPAN metadata files should always have only one document.) If the source was UTF-8 encoded, the string must be decoded before calling "load_yaml_string".

load_json_string

  my $metadata_structure = Parse::CPAN::Meta->load_json_string($json_string);

This method deserializes the given string of JSON and the result. If the source was UTF-8 encoded, the string must be decoded before calling "load_json_string".

load_string

  my $metadata_structure = Parse::CPAN::Meta->load_string($some_string);

If you don't know whether a string contains YAML or JSON data, this method will use some heuristics and guess. If it can't tell, it assumes YAML.

yaml_backend

  my $backend = Parse::CPAN::Meta->yaml_backend;

Returns the module name of the YAML serializer. See ``ENVIRONMENT'' for details.

json_backend

  my $backend = Parse::CPAN::Meta->json_backend;

Returns the module name of the JSON serializer. This will either be JSON::PP or JSON. Even if "PERL_JSON_BACKEND" is set, this will return JSON as further delegation is handled by the JSON module. See ``ENVIRONMENT'' for details.

FUNCTIONS

For maintenance clarity, no functions are exported by default. These functions are available for backwards compatibility only and are best avoided in favor of "load_file".

Load

  my @yaml = Parse::CPAN::Meta::Load( $string );

Parses a string containing a valid YAML stream into a list of Perl data structures.

LoadFile

  my @yaml = Parse::CPAN::Meta::LoadFile( 'META.yml' );

Reads the YAML stream from a file instead of a string.

ENVIRONMENT

PERL_JSON_BACKEND

By default, JSON::PP will be used for deserializing JSON data. If the "PERL_JSON_BACKEND" environment variable exists, is true and is not ``JSON::PP'', then the JSON module (version 2.5 or greater) will be loaded and used to interpret "PERL_JSON_BACKEND". If JSON is not installed or is too old, an exception will be thrown.

PERL_YAML_BACKEND

By default, CPAN::Meta::YAML will be used for deserializing YAML data. If the "PERL_YAML_BACKEND" environment variable is defined, then it is interpreted as a module to use for deserialization. The given module must be installed, must load correctly and must implement the "Load()" function or an exception will be thrown.

SUPPORT

Bugs / Feature Requests

Please report any bugs or feature requests through the issue tracker at <http://rt.cpan.org/Public/Dist/Display.html?Name=Parse-CPAN-Meta>. 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/Parse-CPAN-Meta>

  git clone https://github.com/Perl-Toolchain-Gang/Parse-CPAN-Meta.git

AUTHORS

Adam Kennedy <[email protected]>
David Golden <[email protected]>

CONTRIBUTORS

Graham Knop <[email protected]>
Joshua ben Jore <[email protected]>
Neil Bowers <[email protected]>
Ricardo Signes <[email protected]>
Steffen Mueller <[email protected]>

COPYRIGHT AND LICENSE

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