feat: use normalized checkbox values in field handlers

src/Form/Service/Abstract/AbstractParticipantFieldHandler.php

@@ -153,6 +153,21 @@ abstract class AbstractParticipantFieldHandler implements ParticipantFieldHandle
         return is_numeric($value) ? (int) $value : null;
     }
 
+    /**
+     * Normalizes a checkbox/form toggle value to a boolean.
+     *
+     * Form checkboxes may submit true, false, 1, 0, '1', '0', or be absent.
+     * This method treats only true, 1, and '1' as checked; everything else as unchecked.
+     *
+     * @param mixed $value The raw value from form submission
+     *
+     * @return bool True if the checkbox is considered checked, false otherwise
+     */
+    protected function normalizeCheckboxValue(mixed $value): bool
+    {
+        return true === $value || 1 === $value || '1' === $value;
+    }
+
     /**
      * Returns field state modifications that should be applied after processing.
      *

src/Form/Service/ParticipantBulkInsuranceFieldHandler.php

@@ -68,6 +68,6 @@ class ParticipantBulkInsuranceFieldHandler extends AbstractParticipantFieldHandl
 
         // Get checkbox value from submitted data and store it
         $bulkInsuranceBooking = $this->getFieldValue($submittedData, $this->getFieldName());
-        $participant->bulkInsuranceBooking = (bool) $bulkInsuranceBooking;
+        $participant->bulkInsuranceBooking = $this->normalizeCheckboxValue($bulkInsuranceBooking);
     }
 }

src/Form/Service/ParticipantInsuranceFieldHandler.php

@@ -334,7 +334,7 @@ class ParticipantInsuranceFieldHandler extends AbstractParticipantFieldHandler
 
         // Check if bulk insurance booking is enabled
         $bulkInsuranceBooking = $applicantData['bulkInsuranceBooking'] ?? false;
-        if (false === (bool) $bulkInsuranceBooking) {
+        if (false === $this->normalizeCheckboxValue($bulkInsuranceBooking)) {
             return false;
         }
 

src/Form/Service/ParticipantParkingFieldHandler.php

@@ -66,7 +66,7 @@ class ParticipantParkingFieldHandler extends AbstractParticipantFieldHandler
         }
 
         $parkingSelected = $this->getFieldValue($submittedData, $this->getFieldName());
-        $isParkingSelected = (bool) $parkingSelected;
+        $isParkingSelected = $this->normalizeCheckboxValue($parkingSelected);
 
         // Store boolean value for backward compatibility
         $participant->parking = $isParkingSelected;

src/Form/Service/ParticipantRentalInsuranceFieldHandler.php

@@ -100,7 +100,7 @@ class ParticipantRentalInsuranceFieldHandler extends AbstractParticipantFieldHan
 
         // Extract checkbox value from submitted data (this comes from the rentalInsuranceSelected property)
         $rentalInsuranceSelected = $this->getFieldValue($submittedData, $this->getFieldName());
-        $isRentalInsuranceSelected = (bool) $rentalInsuranceSelected;
+        $isRentalInsuranceSelected = $this->normalizeCheckboxValue($rentalInsuranceSelected);
 
         // Store boolean value
         $participant->rentalInsuranceSelected = $isRentalInsuranceSelected;