Parse::CPAN::Meta(3)

NAME
Parse::CPAN::Meta - Parse META.yml and META.json CPAN metadata files

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. On Perl 5.8.1 or later, 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".

  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. 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 intepreted 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 should be reported via the CPAN bug tracker at

<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Parse-CPAN-Meta>

AUTHOR
Adam Kennedy <adamk@cpan.org>

COPYRIGHT
Copyright 2006 - 2010 Adam Kennedy.

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

The full text of the license can be found in the LICENSE file included with this module.