Parse::CPAN::Meta(3p) Perl Programmers Reference Guide Parse::CPAN::Meta(3p)

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)