NAME

   Catmandu::Store::ElasticSearch - A searchable store backed by
   Elasticsearch

SYNOPSIS

       use Catmandu::Store::ElasticSearch;

       my $store = Catmandu::Store::ElasticSearch->new(index_name => 'catmandu');

       my $obj1 = $store->bag->add({ name => 'Patrick' });

       printf "obj1 stored as %s\n" , $obj1->{_id};

       # Force an id in the store
       my $obj2 = $store->bag->add({ _id => 'test123' , name => 'Nicolas' });

       # Commit all changes
       $store->bag->commit;

       my $obj3 = $store->bag->get('test123');

       $store->bag->delete('test123');

       $store->bag->delete_all;

       # All bags are iterators
       $store->bag->each(sub { ... });
       $store->bag->take(10)->each(sub { ... });

       # Some stores can be searched
       my $hits = $store->bag->search(query => 'name:Patrick');

       # Catmandu::Store::ElasticSearch supports CQL...
       my $hits = $store->bag->search(cql_query => 'name any "Patrick"');

METHODS

new(index_name => $name)

new(index_name => $name , bags => { data => { cql_mapping => \%mapping }
})

new(index_name => $name , index_mapping => $mapping)

   Create a new Catmandu::Store::ElasticSearch store connected to index
   $name.

   The store supports CQL searches when a cql_mapping is provided. This
   hash contains a translation of CQL fields into Elasticsearch searchable
   fields.

    # Example mapping
    $cql_mapping = {
         title => {
           op => {
             'any'   => 1 ,
             'all'   => 1 ,
             '='     => 1 ,
             '<>'    => 1 ,
             'exact' => {field => [qw(mytitle.exact myalttitle.exact)]}
           } ,
           sort  => 1,
           field => 'mytitle',
           cb    => ['Biblio::Search', 'normalize_title']
         }
    }

   The CQL mapping above will support for the 'title' field the CQL
   operators: any, all, =, <> and exact.

   For all the operators the 'title' field will be mapping into the
   Elasticsearch field 'mytitle', except for the 'exact' operator. In case
   of 'exact' we will search both the 'mytitle.exact' and
   'myalttitle.exact' fields.

   The CQL mapping allows for sorting on the 'title' field. If, for
   instance, we would like to use a special Elasticsearch field for
   sorting we could have written "sort => { field => 'mytitle.sort' }".

   The CQL has an optional callback field 'cb' which contains a reference
   to subroutines to rewrite or augment the search query. In this case, in
   the Biblio::Search package there is a normalize_title subroutine which
   returns a string or an ARRAY of string with augmented title(s). E.g.

       package Biblio::Search;

       sub normalize_title {
          my ($self,$title) = @_;
          my $new_title =~ s{[^A-Z0-9]+}{}g;
          $new_title;
       }

       1;

   Optionally, index_mappings contain Elasticsearch schema mappings. E.g.

       # The 'data' index can ony contain one field 'title' of type 'string'
       index_mappings => {
           data => {
               dynamic => 'strict',
               properties => {
                   title => { type => 'string' }
               }
           }
       }

drop

   Deletes the Elasticsearch index backing this store. Calling functions
   after this may fail until this class is reinstantiated, creating a new
   index.

COMPATIBILITY

   This store expects version 1.0 or higher of the Elasticsearch server.

   Note that Elasticsearch >= 2.0 doesn't like keys that start with an
   underscore such as _id. You can use the key_prefix option at store
   level or id_prefix at bag level to handle this.

       # in your catmandu.yml
       store:
         yourstore:
           package: ElasticSearch
           options:
             # use my_id instead of _id
             key_prefix: my_

   If you want to use the delete_by_query method with Elasticsearch >= 2.0
   you will have to install the delete by query plugin
   <https://www.elastic.co/guide/en/elasticsearch/plugins/current/plugins-
   delete-by-query.html>.

MIGRATING A STORE FROM ELASTICSEARCH 1.0 TO 2.0 OR HIGHER

   1. backup your data as JSON

       catmandu export yourstore --bag yourbag to --file /path/to/yourbag.json -v

   2. drop the store

       catmandu drop yourstore

   3. upgrade the Elasticsearch server

   4. update your catmandu.yml with a key_prefix or id_prefix (see
   COMPATIBILITY)

   5. import your data using the new keys specified in your catmandu.yml

       catmandu import --file /path/to/yourbag.json --fix 'move_field(_id, my_id)' \
       to yourstore --bag yourbag -v

ERROR HANDLING

   Error handling can be activated by specifying an error handling
   callback for index when creating a store. E.g. to create an error
   handler for the bag 'data' index use:

       my $store = Catmandu::Store::ElasticSearch->new(
                       index_name => 'catmandu'
                       bags => { data => { on_error => \&error_handler } }
                    });

       sub error_handler {
           my ($action, $response, $i) = @_;
       }

SEE ALSO

   Catmandu::Store

AUTHOR

   Nicolas Steenlant, <nicolas.steenlant at ugent.be>

CONTRIBUTORS

   Dave Sherohman, dave.sherohman at ub.lu.se

   Robin Sheat, robin at kallisti.net.nz

   Patrick Hochstenbach, patrick.hochstenbach at ugent.be

LICENSE AND COPYRIGHT

   This program is free software; you can redistribute it and/or modify it
   under the terms of either: the GNU General Public License as published
   by the Free Software Foundation; or the Artistic License.

   See http://dev.perl.org/licenses/ for more information.