NAME

Catmandu::PerlAPI - A short overview of the current Catmandu Perl API

SYNOPSIS

    use Catmandu;
    # If you have Catmandu::OAI and Catmandu::MongoDB installed
    my $importer = Catmandu->importer('OAI',url => 'https://biblio.ugent.be/oai')
    my $store    = Catmandu->store('MongoDB',database_name => 'test');
    # Import all the OAI records into MongoDB
    $store->add_many($importer);
    # Export all the MongoDB records to YAML and apply some fixes
    # myfixes.txt:
    #   upcase(title.*)
    #   remove_field(_metadata)
    #   join_field(creator,'; ')
    #   join_field(subject,'-- ')
    my $fixer    = Catmandu->fixer('myfixes.txt');
    my $exporter = Catmandu->exporter('YAML');
    $exporter->add_many( $fixer->fix($store) );
    $exporter->commit;

DESCRIPTION

This document provides a short overview of the Perl API of the 1.X version of Catmandu. The Perl API is provided as-is and might change in the future. For a stable implementation of Catmandu we refer to the command line interface of our tool.

USE

To include Catmandu in a Perl script it should be loaded with a "use" command: 
    use Catmandu;
By default no methods are imported into the Perl context. To import all or some Catmandu methods, provide them as a list to the "use" command: 
    use Catmandu -all;
    use Catmandu qw(config store exporter);
Catmandu can load configuration options for exports, importers, fixers via configuration files (see the CONFIG section below). When adding the --load option (optionally with a path) to the "use" command, these configuration files will be loaded at the start of your script. 
    use Catmandu -load;
    use Catmandu -load => ['/my/config/directory'];
    # or use all the options
    use Catmandu -all, -load => [qw(/config/path' '/another/config/path)];

CLASS METHODS

log

Return the current Log::Any logger. 
    use Catmandu;
    use Log::Any::Adapter;
    use Log::Log4perl;
    Log::Any::Adapter->set('Log4perl'); # requires Log::Any::Adapter::Log4perl
    Log::Log4perl::init('./log4perl.conf');
    my $logger = Catmandu->log;
    $logger->info("Starting main program");
with log4perl.conf like: 
    # Send a copy of all logging messages to STDERR
    log4perl.rootLogger=DEBUG,STDERR
    # Logging specific for your main program
    log4perl.category.myprog=INFO,STDERR
    # Logging specific for on part of Catmandu
    log4perl.category.Catmandu::Fix=DEBUG,STDERR
    # Where to send the STDERR output
    log4perl.appender.STDERR=Log::Log4perl::Appender::Screen
    log4perl.appender.STDERR.stderr=1
    log4perl.appender.STDERR.utf8=1
    log4perl.appender.STDERR.layout=PatternLayout
    log4perl.appender.STDERR.layout.ConversionPattern=%d [%P] - %p %l time=%r : %m%n

default_load_path(['/default/path'])

Returns the default location where Catmandu looks for configuration and lib when called with no argument. Sets the default location if a path is given. The default load path is the script directory or it's parent if the script directory is "bin".

load

Load all the configuration options in the catmandu.yml configuration file. See CONFIG below for extended examples of configuration options.

load('/path', '/another/path')

Load all the configuration options stored at alternative paths.
A load path ':up' will search upwards from your program for configuration.
See CONFIG below for extended examples of configuration options.

roots

Returns an ARRAYREF of paths where configuration was found. Note that this list is empty before "load".

root

Returns the first path where configuration was found. Note that this is "undef" before "load".

config

Returns the current configuration as a HASHREF.

config($config)

Set a new configuration and reload the environment.

default_store

Return the name of the default store.

store([NAME])

Return an instance of Catmandu::Store. The NAME is a name of a Catmandu::Store or the name of a store configured in a catmandu.yml configuration file. When no NAME is given, the 'default' store in the configuration file will be used.
E.g. if the configuration file 'catmandu.yml' contains: 
 store:
  default:
   package: ElasticSearch
   options:
     index_name: blog
  test:
   package: Mock
then in your program: 
    # This will use ElasticSearch
    my $store = Catmandu->store('ElasticSearch', index_name => 'blog');
    # or because we have a 'default' set in the configuration file
    my $store = Catmandu->store('default');
    # or because 'default' will be used when no name was provided
    my $store = Catmandu->store;
    # This will use Mock
    my $store = Catmandu->store('test');
Configuration settings can be overwritten by the store command: 
  my $store2 = Catmandu->store('default', index_name => 'test2');

default_fixer

Return the name of the default fixer.

fixer(NAME)

fixer(FIX,FIX)

fixer([FIX])

Return an instance of Catmandu::Fix. NAME can be the name of a fixer section in a catmandu.yml file. Or, one or more Catmandu::Fix-es can be provided inline.
E.g. if the configuration file 'catmandu.yml' contains: 
 fixer:
  default:
    - do_this()
    - do_that()
then in your program al these lines below will create the same fixer: 
    my $fixer = Catmandu->fixer('do_this()', 'do_that()');
    my $fixer = Catmandu->fixer(['do_this()', 'do_that()']);
    my $fixer = Catmandu->fixer('default');
    my $fixer = Catmandu->fixer(); # The default name is 'default'
FIX-es can be also written to a Fix script. E.g. if myfixes.txt contains: 
 do_this()
 do_that()
then the above code will even be equivalent to: 
   my $fixer = Catmandu->fixer('myfixes.txt');

default_importer

Return the name of the default importer.

default_importer_package

Return the name of the default importer package if no package name is given in the config or as a param.

importer(NAME)

Return an instance of Catmandu::Importer. The NAME is a name of a Catmandu::Importer or the name of a importer configured in a catmandu.yml configuration file. When no NAME is given, the 'default' importer in the configuration file will be used.
E.g. if the configuration file 'catmandu.yml' contains: 
  importer:
    default:
      package: OAI
      options:
        url: http://www.instute.org/oai/
then in your program all these lines will be equivalent: 
  my $importer = Catmandu->importer('OAI', url => 'http://www.instute.org/oai/');
  my $importer = Catmandu->importer('default');
  my $importer = Catmandu->importer(); # The default name is 'default'
Configuration settings can be overwritten by the importer command: 
  my $importer2 = Catmandu->importer('default', url => 'http://other.institute.org');

default_exporter

Return the name of the default exporter.

default_exporter_package

Return the name of the default exporter package if no package name is given in the config or as a param.

exporter([NAME])

Return an instance of Catmandu::Exporter with name NAME (or the default when no name is given). The NAME can be in a configuration file (see 'importer').

validator([NAME])

Return an instance of Catmandu::Validator with name NAME (or the default when no name is given). The NAME can be in a configuration file (see 'importer').

export($data,[NAME])

Export data using a default or named exporter or exporter instance. 
    Catmandu->export({ foo=>'bar'});
    my $importer = Catmandu::Importer::Mock->new;
    Catmandu->export($importer, 'YAML', file => '/my/file');
    Catmandu->export($importer, 'my_exporter');
    Catmandu->export($importer, 'my_exporter', exporter_option => '...' , ...);
    Catmantu->export($importer, Catmandu::Exporter::YAML->new);

export_to_string

Export data using a default or named exporter to a string. 
    my $importer = Catmandu::Importer::Mock->new;
    my $yaml = Catmandu->export_to_string($importer, 'YAML');
    # is the same as
    my $yaml = "";
    Catmandu->export($importer, 'YAML', file => \$yaml);

import_from_string

Import data from a string using a default or named importer. Return value should be an array of hashes. 
    my $json = qq([{"name":"Nicolas"}]);
    {
        my $record = Catmandu->import_from_string( $json, "JSON" );
    }
    # is the same as
    {
        my $record = Catmandu->importer('JSON', file => \$json)->to_array()
    }

define_importer

Configure a new named importer. 
    Catmandu->define_importer(books => CSV => (fields => 'title,author,publisher'));
    Catmandu->importer(books => (file => 'mybooks.csv'))->each(sub {
        my $book = shift;
        say $book->{title};
    });
    # this is equivalent to
    Catmandu->config->{importer}{books} = {
        package => 'CSV',
        options => {
            fields => 'title,author,publisher',
        },
    }

define_exporter

Configure a new named exporter. 
    Catmandu->define_exporter('books', 'CSV', fix => 'capitalize(title)');
    my $csv = Catmandu->export_to_string({title => 'nexus'}, 'books');
    # this is equivalent to
    Catmandu->config->{exporter}{books} = {
        package => 'CSV',
        options => {
            fix => 'capitalize(title)',
        },
    }

define_store

Configure a new named store. 
    Catmandu->define_store(mydb => MongoDB => (database_name => 'mydb'));
    Catmandu->store->bag('books')->get(1234);
    # this is equivalent to
    Catmandu->config->{store}{mydb} = {
        package => 'MongoDB',
        options => {
            database_name => 'mydb',
        },
    }

define_fixer

Configure a new named fixer. 
    Catmandu->define_fixer('cleanup', [
        'trim(title)',
        'capitalize(title)',
        'remove_field(junk)',
        # ...
    ]);
    Catmandu->fixer('cleanup')->fix($record);

EXPORTS

config
Same as "Catmandu->config".
store
Same as "Catmandu->store".
importer
Same as "Catmandu->importer".
exporter
Same as "Catmandu->exporter".
validator
Same as "Catmandu->validator".
export
Same as "Catmandu->export".
export_to_string
Same as "Catmandu->export_to_string".
import_from_string
Same as "Catmandu->import_from_string".
fixer
Same as "Catmandu->fixer".
log
Same as "Catmandu->log".
-all/:all
Import everything.
-load/:load
    use Catmandu -load;
    use Catmandu -load => [];
    # is the same as
    Catmandu->load;
    use Catmandu -load => ['/config/path'];
    # is the same as
    Catmandu->load('/config/path');

Questions & Answers

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