wip: field states and dependencies

src/Form/ParticipantFieldHandler/ParticipantFieldHandlerInterface.php

@@ -7,11 +7,12 @@ namespace App\Form\ParticipantFieldHandler;
 use App\Form\Model\BookingCreateDto;
 
 /**
- * Interface for handling dynamic participant form field processing.
+ * Interface for handling dynamic participant form field processing and state modification.
  *
  * Participant field handlers are responsible for processing submitted form data
- * for booking participants and updating the BookingCreateDto accordingly. 
- * They support dependency management to ensure fields are processed in the correct order.
+ * for booking participants and updating the BookingCreateDto accordingly. They also
+ * support field state modification based on processed data and business logic.
+ * Handlers support dependency management to ensure fields are processed in the correct order.
  */
 interface ParticipantFieldHandlerInterface
 {
@@ -40,4 +41,30 @@ interface ParticipantFieldHandlerInterface
      * Determines if this handler should process the field based on submitted participant data.
      */
     public function shouldProcess(array $submittedData, int $participantIndex): bool;
+
+    /**
+     * Returns field state modifications that should be applied after processing.
+     *
+     * This method allows handlers to dynamically modify the state of form fields
+     * based on the processed data. It's called after processField() and can be used
+     * to enable/disable/hide fields based on the handler's processing results.
+     *
+     * @param array<string, mixed> $submittedData    The submitted participant form data
+     * @param BookingCreateDto     $bookingDto       The booking DTO (potentially modified by processing)
+     * @param int                  $participantIndex The participant index being processed
+     *
+     * @return array<string, array<string, mixed>> Field state modifications indexed by field name
+     */
+    public function getFieldStateModifications(array $submittedData, BookingCreateDto $bookingDto, int $participantIndex): array;
+
+    /**
+     * Returns field names whose state is affected by this handler's processing.
+     *
+     * This method declares which form fields have their state modified by this handler.
+     * It's used for dependency tracking and determining when field states need to be
+     * recalculated during form processing.
+     *
+     * @return string[] Array of field names that this handler may modify the state of
+     */
+    public function getAffectedFieldNames(): array;
 }