Things get a bit more complicated with MM-relations, where additional configuration is required. The related properties are described below.
If all this seems a bit confusing, please refer to the chapter about mapping MM relations. Hopefully it will help (this is not a simple topic).
- List of fields that must be stored along the local and foreign keys in the MM table. For each such field, define which TYPO3 CMS MM-table field corresponds to which external data field.
- Store data
- If some MM-relations exist several times in your external data (because they have various additional fields), you must set this property to 1, so that they are preserved (otherwise the TYPO3 Core Engine will take only unique “uid_local”-“uid_foreign” pairs into account).
- Store data
Indicates that the data is to be sorted according to that particular field from the external data.
Note that since the external import relies on the TYPO3 Core Engine to store the data, which sets its own numbering for sorting, thus the value in sorting is never used as is, but just for ordering the records. So if the records in the external source are already sorted, there’s no need to define the “sorting” property.
- Store data
When the additionalFields and/or multiple properties are used, additional database operations are performed to honour these settings, as it is not traditional behaviour for TYPO3 MM-relations. It should be possible with IRRE, but this isn’t supported yet.
Also note that these extra operations assume that the MM-relation
is defined as originating from the currently imported table.
This means that if you are importing table “foo” and its relations
to table “bar”, the import script assumes that the foreign keys of
table “foo” are going into the
uid_local column. Importing
from the “other” side is not supported yet.
This example shows how the “employee” field of the external data is mapped to the “fe_users” table to consitute the list of members in a team.
'members' => array( 'exclude' => 0, 'label' => 'LLL:EXT:externalimport_tut/locallang_db.xml:tx_externalimporttut_teams.members', 'config' => array( 'type' => 'group', 'size' => 5, 'internal_type' => 'db', 'allowed' => 'fe_users', 'MM' => 'tx_externalimporttut_teams_feusers_mm', 'maxitems' => 100 ), 'external' => array( 0 => array( 'field' => 'employee', 'MM' => array( 'mapping' => array( 'table' => 'fe_users', 'referenceField' => 'tx_externalimporttut_code', 'default' => '' ), 'sorting' => 'rank' ) ) ) ),