Parse::CPAN::Meta(3pm)         User Contributed Perl Documentation         Parse::CPAN::Meta(3pm)



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

VERSION
       version 2.150010

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.  If "CPAN_META_JSON_BACKEND" is set, this
       will be whatever that's set to.  If not, this will either be JSON::PP or JSON.  If
       "PERL_JSON_BACKEND" is set, this will return JSON as further delegation is handled by the
       JSON module.  See "ENVIRONMENT" for details.

   json_decoder
         my $decoder = Parse::CPAN::Meta->json_decoder;

       Returns the module name of the JSON decoder.  Unlike "json_backend", this is not
       necessarily a full JSON-style module, but only something that will provide a "decode_json"
       subroutine.  If "CPAN_META_JSON_DECODER" is set, this will be whatever that's set to.  If
       not, this will be whatever has been selected as "json_backend".  See "ENVIRONMENT" for
       more notes.

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
   CPAN_META_JSON_DECODER
       By default, JSON::PP will be used for deserializing JSON data.  If the
       "CPAN_META_JSON_DECODER" environment variable exists, this is expected to be the name of a
       loadable module that provides a "decode_json" subroutine, which will then be used for
       deserialization.  Relying only on the existence of said subroutine allows for maximum
       compatibility, since this API is provided by all of JSON::PP, JSON::XS, Cpanel::JSON::XS,
       JSON::MaybeXS, JSON::Tiny, and Mojo::JSON.

   CPAN_META_JSON_BACKEND
       By default, JSON::PP will be used for deserializing JSON data.  If the
       "CPAN_META_JSON_BACKEND" environment variable exists, this is expected to be the name of a
       loadable module that provides the JSON API, since downstream code expects to be able to
       call "new" on this class.  As such, while JSON::PP, JSON::XS, Cpanel::JSON::XS and
       JSON::MaybeXS will work for this, to use Mojo::JSON or JSON::Tiny for decoding requires
       setting "CPAN_META_JSON_DECODER".

   PERL_JSON_BACKEND
       If the "CPAN_META_JSON_BACKEND" environment variable does not exist, and if
       "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.
       Note that at the time of writing, the only useful values are 1, which will tell JSON to
       guess, or JSON::XS - if you want to use a newer JSON module, see "CPAN_META_JSON_BACKEND".

   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.

AUTHORS
       ·   David Golden <dagolden AT cpan.org>

       ·   Ricardo Signes <rjbs AT cpan.org>

       ·   Adam Kennedy <adamk AT 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.



perl v5.20.2                                2016-08-18                     Parse::CPAN::Meta(3pm)