How do I add a field to a node form?

Interlated

2/26/23, 11:52 PM

The goal is to set a default counter, but let people override it. The counter should be the biggest value of the field plus 1.

Using an event subscriber, FORM ALTER event.

public static function getSubscribedEvents(): array {
  return [
    HookEventDispatcherInterface::FORM_ALTER => 'setDefaultCbid',
    HookEventDispatcherInterface::ENTITY_PRE_SAVE => 'checkCbiRaceCondition'
  ];
}


public function setDefaultCbid(FormAlterEvent $event) {

  $form_id = $event->getFormId();
  if ($form_id !== 'node_bond_edit_form') {
    return;
  }

  $result = \Drupal::database()
    ->query('select max(field_bond_cbid_value) from {node__field_bond_cbid}')
    ->fetchField();

  if ($result) {
    $cbid = $result + 1;
  }
  else {
    $cbid = 1;
  }

  $form = &$event->getForm();
  $form_already_alterered = false;
  if (array_key_exists('field_bond_cbid_default', $form)) {
    $form_already_alterered = TRUE;
  }
  $form['field_bond_cbid_default'] = [
    '#title' => $this->t('default cbid'),
    '#type' => 'number',
    '#value' => $cbid,
  ];

  if (!$form_already_alterered) {
    $form['field_bond_cbid']['widget'][0]['value']['#default_value'] = $cbid;
  }
}

This works fine. The value is set and the "default" field visible in the adjusted form

What happens if a second person edits another node and increments the counter whINCORRECTCODEile the form is displayed? This is where field_bond_cbid_default is not available on the entity

public function checkCbiRaceCondition(EntityPresaveEvent $event) {   

  $bond = $event->getEntity();
  if ($bond->bundle() !== 'bond') {
  return;
}

$enteredValue = $bond->get('field_bond_cbid')->getString();
$defaultCbid = $bond->get('field_bond_cbid_default')->getString();
if ($enteredValue != $defaultCbid) {

How do I access the default value?

0 + 0

forms

webforms

Score:2

Drupal

Interlated

2/27/23, 3:27 AM

The form alter event is the wrong event for checking data. Instead of trying to deal with the form, use the backing entity.

On form alter event add a submit handler

$form['actions']['submit']['#submit'][]  = [$this, 'checkCbid'];

Check that the value is the latest on submit

public function checkCbiRaceCondition(&$form, FormState &$form_state) {
  $enteredValue = $form_state->getValue('field_bond_cbid')[0]['value'];
  $defaultCbid = $form['field_bond_cbid']['widget'][0]['value']['#default_value'];
  if (intval($enteredValue) != $defaultCbid) {
    return;
  }

  $result = \Drupal::database()
    ->query('select max(field_bond_cbid_value) from {node__field_bond_cbid}')
    ->fetchField();

  if ($result) {
    $cbid = $result +1;
  } else {
    $cbid = 1;
  }

  $form_state->set('field_bond_cbid', $cbid);
}

0 + 0