TYPO3 TCA selectCheckBox not working with extension femanager - typo3

Question

I've created a selectCheckBox in TYPO3 like this:
'region' => [
'exclude' => true,
'label' => 'LLL:EXT:myext/Resources/Private/Language/locallang_db.xlf:tx_myext_domain_model_catalog.region',
'config' => [
'type' => 'select',
'renderType' => 'selectCheckBox',
'items' => [
['LLL:EXT:myext/Resources/Private/Language/locallang_db.xlf:tx_myext_domain_model_catalog.region.1', 1],
['LLL:EXT:myext/Resources/Private/Language/locallang_db.xlf:tx_myext_domain_model_catalog.region.2', 2],
['LLL:EXT:myext/Resources/Private/Language/locallang_db.xlf:tx_myext_domain_model_catalog.region.3', 3],
['LLL:EXT:myext/Resources/Private/Language/locallang_db.xlf:tx_myext_domain_model_catalog.region.4', 4],
],
],
],
When I save it, the database has the comma separated IDs as value like:
1,3,4
Now I want to get the value in frontend via the femanager extension.
I've created this configuration for it:
/**
* region
*
* #var array
*/
protected $region = [];
/**
* Returns the region
*
* #return array $region
*/
public function getRegion()
{
return $this->region;
}
/**
* Sets the region
*
* #param array $region
* #return void
*/
public function setRegion($region)
{
$this->region = $region;
}
Database Configuration:
region varchar(255) DEFAULT '' NOT NULL,
But when I try to debug the output like this:
<f:debug>{catalog.region}</f:debug>
It just says this:
array(empty)
So my getRegion function isn't working. Can somebody please give me a hint why it isn't getting the values.

Answer 1

$region is declared to be an array and your setter setRegion() is expecting an array as parameter. But the stored value in the database is a varchar. So, the mapping of the database record on your model will fail for this property.
This is working with your TCA:
/**
* #var string
*/
protected string $region = '';
/**
* #return array
*/
public function getRegion(): array
{
return GeneralUtility::intExplode(',', $this->region, true);
}
/**
* #param mixed $region
*/
public function setRegion($region): void
{
$this->region = (is_array($region) ? implode(',', array_filter($region, 'is_int')) : $region);
}