NAME

Catmandu::Fix - a Catmandu class used for data crunching

SYNOPSIS

use Catmandu::Fix;

my $fixer = Catmandu::Fix->new(fixes => ['upcase("job")','remove_field("test")']);

or

my $fixer = Catmandu::Fix->new(fixes => ['fix_file.txt']);

my $arr  = $fixer->fix([ ... ]);
my $hash = $fixer->fix({ ... });

my $it = Catmandu::Importer::YAML(file => '...');
$fixer->fix($it)->each(sub {
    ...
});

or

use Catmandu::Fix::upcase as => 'my_upcase';
use Catmandu::Fix::remove_field as => 'my_remove';

my $hash = { 'job' => 'librarian' , deep => { nested => '1'} };

my_upcase($hash,'job');
my_remove($hash,'deep.nested');

DESCRIPTION

Catmandu::Fixes can be used for easy data manipulation by non programmers. Using a small Perl DSL language end-users can use Fix routines to manipulate data objects. A plain text file of fixes can be created to specify all the routines needed to tranform the data into the desired format.

PATHS

All the Fix routines in Catmandu::Fix use a TT2 type reference to point to values in a Perl Hash. E.g. 'foo.2.bar' is a key 'bar' which is the 3-rd value of the key 'foo'.

A special case is when you want to point to all items in an array. In this case the wildcard '*' can be used. E.g. 'foo.*' points to all the items in the 'foo' array.

For array values there are special wildcards available:

* $append   - Add a new item at the end of an array
* $prepend  - Add a new item at the start of an array
* $first    - Syntactic sugar for index '0' (the head of the array)
* $last     - Syntactic sugar for index '-1' (the tail of the array)

E.g.

# Create { mods => { titleInfo => [ { 'title' => 'a title' }] } };
add_field('mods.titleInfo.$append.title', 'a title');

# Create { mods => { titleInfo => [ { 'title' => 'a title' } , { 'title' => 'another title' }] } };
add_field('mods.titleInfo.$append.title', 'another title');

# Create { mods => { titleInfo => [ { 'title' => 'foo' } , { 'title' => 'another title' }] } };
add_field('mods.titleInfo.$first.title', 'foo');

# Create { mods => { titleInfo => [ { 'title' => 'foo' } , { 'title' => 'bar' }] } };
add_field('mods.titleInfo.$last.title', 'bar');

Read more about the Fix language at our Wiki: https://github.com/LibreCat/Catmandu/wiki/Fixes

METHODS

new(fixes => [ FIX , ...])

Create a new Catmandu::Fix which will execute every FIX into a consecutive order. A FIX can be the name of a Catmandu::Fix::* routine or the path to a plain text file containing all the fixes to be executed.

fix(HASH)

Execute all the fixes on a HASH. Returns the fixed HASH.

fix(ARRAY)

Execute all the fixes on every element in the ARRAY. Returns an ARRAY of fixes.

fix(Catmandu::Iterator)

Execute all the fixes on every item in an Catmandu::Iterator. Returns a (lazy) iterator on all the fixes.

fix(sub {})

Executes all the fixes on a generator function. Returns a new generator with fixed data.

log

Return the current logger. Can be used when creating your own Fix commands.

E.g.

package Catmandu::Fix::meow;

use Moo;

sub fix {
    my ($self,$data) = @_;

    $self->log->debug("Setting meow");
    $data->{meow} = 'purrrrr';

    $data;
}

See also: Catmandu for activating the logger in your main code.