table of contents
| Catmandu::Exporter(3pm) | User Contributed Perl Documentation | Catmandu::Exporter(3pm) |
NAME¶
Catmandu::Exporter - Namespace for packages that can exportSYNOPSIS¶
# From the command line
# JSON is an importer and YAML an exporter
$ catmandu convert JSON to YAML < data.json
# OAI is an importer and JSON an exporter
$ catmandu convert OAI --url http://biblio.ugent.be/oai to JSON
# From Perl
use Catmandu;
my $importer = Catmandu->importer('JSON', file => 'data.json');
my $exporter = Catmandu->exporter('YAML');
$exporter->add({ record => "one"});
$exporter->add_many([ { record => "one" } , { record => "two" } ]);
$exporter->add_many($importer);
$exporter->commit;
undef($exporter); # Clean up memory
DESCRIPTION¶
A Catmandu::Exporter is a Perl package that can export data into JSON, YAML, XML or many other formats. By default, data is to STDOUT. Optionally provide a "file" or "fh" parameter to write to a file, string, or handle.Every Catmandu::Exporter is a Catmandu::Fixable thus provides a "fix" parameter and method to apply fixes to exported items:
my $exporter = Catmandu->exporter('JSON', fix => ['upcase(title)']);
# This will be printed to STDOUT like: {"title":"MY TITLE"}
$exporter->add({ title => "my title"});
Every Catmandu::Exporter is a Catmandu::Addable thus inherits the methods "add" and "add_many".
CONFIGURATION¶
- file
- Write output to a local file given by its path or file handle. Alternatively a scalar reference can be passed to write to a string and a code reference can be used to write to a callback function.
- fh
- Write the output to an IO::Handle. If not specified, Catmandu::Util::io is
used to create the output handle from the
"file" argument or by using STDOUT.
It is the task of the Perl programmer to close any opened IO::Handles. Catmandu will not do this by itself.
- encoding
- Binmode of the output stream "fh". Set to "":utf8"" by default.
- fix
- An ARRAY of one or more fixes or file scripts to be applied to exported items.
METHODS¶
add¶
Adds one item to be exported.add_many¶
Adds many items to be exported. This can be either an ARRAY-ref or an Catmandu::Iterator. Returns a true value when the export was successful or undef on error.count¶
Returns the number of items exported by this Catmandu::Exporter.log¶
Returns the current logger.commit¶
Commit all buffers to the output handle.CODING¶
Create your own exporter by creating a Perl package in the Catmandu::Exporter namespace that implements "Catmandu::Exporter". Basically, you need to create a method add which writes a Perl hash to a file handle: package Catmandu::Exporter::Foo;
use Catmandu::Sane;
use Moo;
with 'Catmandu::Exporter'
sub add {
my ($self, $data) = @_;
my $fh = $self->fh;
$fh->print( "Hello, World!");
}
sub commit {
my ($self) = @_;
# this will be called at the end of the record stream
}
1;
This exporter can be called from the command line as:
$ catmandu convert JSON to Foo < data.json
Or, via Perl
use Catmandu;
my $exporter = Catmandu->exporter('Foo', file => "/tmp/output.txt");
$exporter->add({test => 123});
$exporter->commit;
undef($exporter);
SEE ALSO¶
See function export_to_string in module Catmandu.The exporters Catmandu::Exporter::JSON, Catmandu::Exporter::YAML, Catmandu::Exporter::CSV, and Catmandu::Exporter::Text are included in Catmandu core.
See Catmandu::Importer for the opposite action.
| 2019-01-29 | perl v5.28.1 |