Parse::CPAN::Meta(3p) Perl Programmers Reference Guide Parse::CPAN::Meta(3p) #
Parse::CPAN::Meta(3p) Perl Programmers Reference Guide Parse::CPAN::Meta(3p)
NNAAMMEE #
Parse::CPAN::Meta - Parse META.yml and META.json CPAN metadata files
VVEERRSSIIOONN #
version 2.150010
SSYYNNOOPPSSIISS #
#############################################
# 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};
DDEESSCCRRIIPPTTIIOONN #
PPaarrssee::::CCPPAANN::::MMeettaa is a parser for _M_E_T_A_._j_s_o_n and _M_E_T_A_._y_m_l files, using
JSON::PP and/or CPAN::Meta::YAML.
PPaarrssee::::CCPPAANN::::MMeettaa 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.
PPaarrssee::::CCPPAANN::::MMeettaa 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.
MMEETTHHOODDSS #
llooaadd__ffiillee 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.
llooaadd__yyaammll__ssttrriinngg 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".
llooaadd__jjssoonn__ssttrriinngg 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".
llooaadd__ssttrriinngg 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. #
yyaammll__bbaacckkeenndd my $backend = Parse::CPAN::Meta->yaml_backend;
Returns the module name of the YAML serializer. See "ENVIRONMENT" for
details.
jjssoonn__bbaacckkeenndd 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.
jjssoonn__ddeeccooddeerr 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.
FFUUNNCCTTIIOONNSS #
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".
LLooaadd my @yaml = Parse::CPAN::Meta::Load( $string );
Parses a string containing a valid YAML stream into a list of Perl data
structures.
LLooaaddFFiillee my @yaml = Parse::CPAN::Meta::LoadFile( ‘META.yml’ );
Reads the YAML stream from a file instead of a string.
EENNVVIIRROONNMMEENNTT #
CCPPAANN__MMEETTAA__JJSSOONN__DDEECCOODDEERR #
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.
CCPPAANN__MMEETTAA__JJSSOONN__BBAACCKKEENNDD #
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”. #
PPEERRLL__JJSSOONN__BBAACCKKEENNDD #
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”. #
PPEERRLL__YYAAMMLL__BBAACCKKEENNDD #
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.
AAUUTTHHOORRSS #
• David Golden <dagolden@cpan.org>
• Ricardo Signes <rjbs@cpan.org>
• Adam Kennedy <adamk@cpan.org>
CCOOPPYYRRIIGGHHTT AANNDD LLIICCEENNSSEE #
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 v5.36.3 2019-02-13 Parse::CPAN::Meta(3p)