--- /dev/null
+<?php
+
+namespace Drupal\batch_test\Form;
+
+use Drupal\Core\Form\FormBase;
+use Drupal\Core\Form\FormStateInterface;
+
+/**
+ * Generate form of id batch_test_simple_form.
+ */
+class BatchTestSimpleForm extends FormBase {
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getFormId() {
+ return 'batch_test_simple_form';
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function buildForm(array $form, FormStateInterface $form_state) {
+ $form['batch'] = [
+ '#type' => 'select',
+ '#title' => 'Choose batch',
+ '#options' => [
+ 'batch_0' => 'batch 0',
+ 'batch_1' => 'batch 1',
+ 'batch_2' => 'batch 2',
+ 'batch_3' => 'batch 3',
+ 'batch_4' => 'batch 4',
+ ],
+ ];
+ $form['submit'] = [
+ '#type' => 'submit',
+ '#value' => 'Submit',
+ ];
+
+ return $form;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function submitForm(array &$form, FormStateInterface $form_state) {
+ batch_test_stack(NULL, TRUE);
+
+ $function = '_batch_test_' . $form_state->getValue('batch');
+ batch_set($function());
+
+ $form_state->setRedirect('batch_test.redirect');
+ }
+
+}