Select multiple values (selectSingleBox) 

Only useful if foreign_table is enabled.

If set, then values which are not integer ids will be allowed. May be needed if you use itemsProcFunc or enter additional items in the items array to produce some string-value elements for the list.

Authorization mode for the selector box. The only possible option is:

explicitAllow

All static values from the "items" array of the selector box will be added to a matrix in the backend user configuration where a value must be explicitly selected if a user (other than admin) is allowed to use it!)

The TCA config option dbFieldLength contains an integer value that is applied to varchar fields (not text ) and defines the length of the database field. It will not be respected for fields that resolve to an integer type. Developers who wish to optimize field length can use dbFieldLength for type=select fields to increase or decrease the default length.

Default value set if a new record is created. If empty, the first element in the items array is selected.

If set, then no element is inserted if the current value does not match any of the existing elements. A corresponding options is also found in Page TSconfig.

For details see fieldInformation.

The item-array will be filled with records from the table defined here. The table must have a TCA definition.

The uids of the chosen records will be saved in a comma separated list by default.

Use property MM to store the values in an intermediate MM table instead.

This property references a specific field in the foreign table, which holds an item group identifier.

See also foreign_table_item_group.

Label prefix to the title of the records from the foreign-table.

The items from foreign_table are selected with this WHERE clause. The WHERE clause is effectively appended to the existing WHERE clause (which contains default constraints, such as NOT deleted ) and must begin with AND .

Contains an array of key-value pairs. The key contains the id of the item group, the value contains the label of the item group or its language reference.

Only groups containing items will be displayed. In the select field first all items with no group defined are listed then the item groups in the order of their definition, each group with the corresponding items.

Item groups are rendered as <optgroup> .

Item groups can also be defined for items in foreign tables.

See also item group API methods

Contains the elements for the selector box unless the property foreign_table or special has been set in which case automated values are set in addition to any values listed in this array.

For examples see also property items of singleSelect.

An array indexed numerically. Each entry defines an item processor implementing ItemsProcessorInterface .

Item processors are executed sequentially based on their numerical array key. Each processor can add, modify, or remove items from the SelectItemCollection , influencing which items are ultimately displayed.

This option can be combined with itemsProcFunc. If both are configured, itemsProcFunc is executed first and itemsProcessors are executed afterwards.

<?php

use MyVendor\MyExtension\Backend\ItemsProcessor\TimezoneItemsProcessor;
use MyVendor\MyExtension\Backend\TimezoneSorter;
use TYPO3\CMS\Core\Utility\ExtensionManagementUtility;

defined('TYPO3') or die();

ExtensionManagementUtility::addTCAcolumns('tx_myextension_conference', [
  'timezone' => [
    'label' => 'my_extension.db:conference.timezone',
    'config' => [
      'type' => 'select',
      'renderType' => 'selectSingle',
      'items' => [
        ['label' => '', 'value' => ''],
      ],
      'itemsProcessors' => [
        100 => [
          'class' => TimezoneItemsProcessor::class,
          'parameters' => [
            'regions' => 'Europe,America',
          ],
        ],
      ],
      'itemGroups' => [
        'Europe' => 'my_extension.db:conference.timezone.europe',
        'America' => 'my_extension.db:conference.timezone.america',
      ],
      'sortItems' => [
        'label' => 'asc',
        // Then by the offset to UTC, the time zones with the same offset
        // stay sorted by label
        'offset' => TimezoneSorter::class . '->sortByOffset',
      ],
      'dbFieldLength' => 64,
      'behaviour' => [
        'allowLanguageSynchronization' => true,
      ],
    ],
  ],
]);
ExtensionManagementUtility::addToAllTCAtypes(
  'tx_myextension_conference',
  'timezone',
  '',
  'after:location',
);

For fields of type select, each SelectItem must be created with type: 'select' and must provide a label and a value. The value can be an integer or a string. Use the special value '--div--' to insert a divider (that cannot be selected).

You can also use any arguments supported by the items array, including group to group items. Rendering the icon or description is not supported.

<?php

declare(strict_types=1);

namespace MyVendor\MyExtension\Backend\ItemsProcessor;

use TYPO3\CMS\Core\DataHandling\ItemsProcessorContext;
use TYPO3\CMS\Core\DataHandling\ItemsProcessorInterface;
use TYPO3\CMS\Core\Schema\Struct\SelectItem;
use TYPO3\CMS\Core\Schema\Struct\SelectItemCollection;

/**
 * Offers the time zones of the regions given in the parameter "regions",
 * grouped by region
 */
final readonly class TimezoneItemsProcessor implements ItemsProcessorInterface
{
  public function processItems(
    SelectItemCollection $items,
    ItemsProcessorContext $context,
  ): SelectItemCollection {
    $regions = explode(',', (string)($context->processorParameters['regions'] ?? 'Europe'));
    foreach (\DateTimeZone::listIdentifiers() as $identifier) {
      [$region, $city] = array_pad(explode('/', $identifier, 2), 2, '');
      if ($city === '' || !in_array($region, $regions, true)) {
        continue;
      }
      $items->add(new SelectItem(
        type: 'select',
        label: str_replace('_', ' ', $city),
        value: $identifier,
        group: $region,
      ));
    }
    return $items;
  }
}

See also Item processor registration and implementation

PHP method which is called to fill or manipulate the items array. See itemsProcFunc about details.

Defines whether referenced records should be localized when the current record gets localized. This only applies if references are not stored using MM tables.

Maximum number of child items. Defaults to a high value. JavaScript record validation prevents the record from being saved if the limit is not satisfied.

Minimum number of child items. Defaults to 0. JavaScript record validation prevents the record from being saved if the limit is not satisfied.

This value contains the name of the table in which to store a MM relation. It is used together with foreign_table.

The database field with a MM property only stores the number of records in the relation.

Please have a look into the additional information in the MM common property description.

Array of field => value pairs to both insert and match against when writing/reading MM relations.

If you want to make a MM relation editable from the foreign side (bidirectional) of the relation as well, you need to set MM_opposite_field on the foreign side to the field name on the local side.

For example, if the field companies.employees is your local side and you want to make the same relation editable from the foreign side of the relation in a field called persons.employers, you would need to set the MM_opposite_field value of the TCA configuration of the persons.employers field to the string "employees".

In a MM bidirectional relation using match fields the opposite side needs to know about the match fields for certain operations (for example, when a copy is created in a workspace) so that relations are carried over with the correct information.

MM_oppositeUsage is an array which references which fields contain the references to the opposite side, so that they can be queried for match field configuration.

Additional where clause used when reading MM relations.

Example:

{#uid_local} = ###THIS_UID###

The above example uses the special field quoting syntax {#...} around identifiers to be as DBAL-compatible as possible.

Allows the same item more than once in a list.

If used with bidirectional MM relations it must be set for both the native and foreign field configuration.

Renders the field in a way that the user can see the value but cannot edit it.

Defines whether the field holds one related record or several, if it relates to records through foreign_table. This decides which value a Record object provides for this field, for example in a Fluid template.

oneToOne, manyToOne

The field provides a single Record object, or null if no record is selected. maxitems is set to 1 automatically, overriding any other value.

oneToMany

The field provides a LazyRecordCollection of Record objects.

A field with MM always provides a collection, whatever relationship says. Any other value, including manyToMany, throws an exception unless MM is set.

maxitems does not change the result the other way round: a field with oneToMany still provides a collection, even if maxitems is 1.

A select field without foreign_table has no relation. It provides an array of the selected values, or the single value for renderType => 'selectSingle'.

If relationship is not set, a field with foreign_table provides a collection.

By default a field of type select and any render type is hidden when no select items are available. Setting showIfEmpty to true, shows the field even if no options are available.

$GLOBALS['TCA']['pages']['columns']['some_select_field']['config']['showIfEmpty'] = true;

Possible reasons, why no select items are available:

• foreign_table was used and the referenced table has no records or none matching the foreign_table_where.
• foreign_table was used and the currently logged in user has not permissions for the referenced table or all of it records.
• All items have been hidden via page TSconfig, for example via removeItems or keepItems is inproperly configured.
• The itemsProcessors or itemsProcFunc had no result.

Height of the box in FormEngine. This value should not be set to a number smaller than 2.