ISTWCMS-4586: Adding ajax on form alter for profile content type.

uw_ct_profile.module

+<?php
+
+/**
+ * @file
+ * Profile module file.
+ */
+
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\node\Entity\Node;
+
+/**
+ * Implements hook_form_FORM_ID_alter().
+ */
+function uw_ct_profile_form_node_uw_ct_profile_form_alter(&$form, FormStateInterface $form_state, $form_id): void {
+  $form['field_uw_ct_profile_contact']['widget'][0]['target_id']['#ajax'] = [
+    'callback' => '_uw_ct_profile_node_form_callback',
+    'event' => 'change',
+    'wrapper' => $form['#id'],
+  ];
+
+  if ($form['field_uw_ct_profile_contact']['widget'][0]['target_id']) {
+    foreach (_uw_ct_profile_alter_fields() as $profile_field => $contact_field) {
+//      $form[$profile_field]['widget'][0]['value']['#value'] = $contact->$contact_field->value;
+      $form[$profile_field]['widget'][0]['value']['#attributes']['readonly'] = 'readonly';
+    }
+  }
+}
+
+/**
+ * Implements hook_form_FORM_ID_EDIT_FORM_alter().
+ */
+function uw_ct_profile_form_node_uw_ct_profile_edit_form_alter(&$form, FormStateInterface $form_state, $form_id): void {
+  uw_ct_profile_form_node_uw_ct_profile_form_alter($form, $form_state, $form_id);
+}
+
+/**
+ * Ajax call back function used in form alter.
+ */
+function _uw_ct_profile_node_form_callback(array &$form, FormStateInterface $form_state): array {
+  $contact_nid = $form_state->getValue('field_uw_ct_profile_contact')[0]['target_id'];
+
+  foreach (_uw_ct_profile_alter_fields() as $profile_field => $contact_field) {
+    if ($contact_nid && is_numeric($contact_nid) && $contact = Node::load($contact_nid)) {
+      // Copy value from the contact associated with this profile node.
+      $form[$profile_field]['widget'][0]['value']['#value'] = $contact->$contact_field->value;
+      // Set read only flag. Can't use #disabled (#states) since disabled fields
+      // are not sent with submit (omitted). Validation will fail on req fields.
+      $form[$profile_field]['widget'][0]['value']['#attributes']['readonly'] = 'readonly';
+    }
+    else {
+      // Clear the read only flag, allow field to be edited.
+      unset($form[$profile_field]['widget'][0]['value']['#attributes']['readonly']);
+    }
+  }
+
+  return $form;
+}
+
+/**
+ * Fields to sync.
+ *
+ * @return string[]
+ *   Mapping of fields profile => contact.
+ */
+function _uw_ct_profile_alter_fields(): array {
+  return [
+    'title' => 'title',
+    'field_uw_ct_profile_sort_name' => 'field_uw_ct_contact_sort_name',
+    'field_uw_ct_profile_affiliation' => 'field_uw_ct_contact_affiliation',
+    'field_uw_ct_profile_title' => 'field_uw_ct_contact_title',
+  ];
+}
+
+