NAME
Parse::CPAN::Meta - Parse META.yml and META.json CPAN metadata files
VERSION
version 1.4418
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.
SUPPORT
Bugs / Feature Requests
Please report any bugs or feature requests through the issue tracker at https://github.com/Perl-ToolChain-Gang/Parse-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/Parse-CPAN-Meta
git clone https://github.com/Perl-ToolChain-Gang/Parse-CPAN-Meta.gitAUTHORS
Adam Kennedy <adamk@cpan.org>
David Golden <dagolden@cpan.org>
CONTRIBUTORS
Graham Knop <haarg@haarg.org>
Joshua ben Jore <jjore@cpan.org>
Karen Etheridge <ether@cpan.org>
Matt S Trout <mst@shadowcat.co.uk>
Neil Bowers <neil@bowers.com>
Ricardo Signes <rjbs@cpan.org>
Steffen Mueller <smueller@cpan.org>
COPYRIGHT AND LICENSE
This software is copyright (c) 2016 by 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.