Add profile form fields to user registration page. Processing of thes…

…e values isn't happening yet.

civicrm.module

@@ -233,4 +233,34 @@ function _civicrm_get_profiles($contact_id) {
     }
   }
   return $profiles;
+}
+
+/**
+ * Implements hook_form_TAG_ID_alter().
+ *
+ * Attach any relevant profile form fields to user registration form.
+ */
+function civicrm_form_user_register_form_alter(&$form, &$form_state, $form_id) {
+  $civicrm = \Drupal::service('civicrm');
+  $html = \CRM_Core_BAO_UFGroup::getEditHTML(NULL, '', 1, TRUE, FALSE, NULL, FALSE, $civicrm->getCtype());
+
+  $form['civicrm_profile_register'] = array(
+    '#markup' => $html,
+  );
+  $form['#validate'][] = '_civicrm_user_register_form_validate';
+}
+
+/**
+ * Validation function for additional profile form fields attached to user registration form.
+ */
+function _civicrm_user_register_form_validate(&$form, &$form_state) {
+  \Drupal::service('civicrm');
+  $errors = CRM_Core_BAO_UFGroup::isValid(NULL, '', TRUE);
+
+  if (is_array($errors)) {
+    $form_builder = \Drupal::formBuilder();
+    foreach ($errors as $name => $message) {
+      $form_builder->setErrorByName($name, $form_state, $message);
+    }
+  }
 }