--- /dev/null
+<?php
+
+namespace Drupal\devel\Form;
+
+use Drupal\Component\Utility\Html;
+use Drupal\Core\Form\FormBase;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Url;
+
+/**
+ * Form that displays all the config variables to edit them.
+ */
+class ConfigsList extends FormBase {
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getFormId() {
+ return 'devel_config_system_form';
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function buildForm(array $form, FormStateInterface $form_state, $filter = '') {
+ $form['filter'] = array(
+ '#type' => 'details',
+ '#title' => t('Filter variables'),
+ '#attributes' => array('class' => array('container-inline')),
+ '#open' => isset($filter) && trim($filter) != '',
+ );
+ $form['filter']['name'] = array(
+ '#type' => 'textfield',
+ '#title' => $this->t('Variable name'),
+ '#title_display' => 'invisible',
+ '#default_value' => $filter,
+ );
+ $form['filter']['show'] = array(
+ '#type' => 'submit',
+ '#value' => $this->t('Filter'),
+ );
+
+ $header = array(
+ 'name' => array('data' => $this->t('Name')),
+ 'edit' => array('data' => $this->t('Operations')),
+ );
+
+ $rows = array();
+
+ $destination = $this->getDestinationArray();
+
+ // List all the variables filtered if any filter was provided.
+ $names = $this->configFactory()->listAll($filter);
+
+ foreach ($names as $config_name) {
+ $operations['edit'] = array(
+ 'title' => $this->t('Edit'),
+ 'url' => Url::fromRoute('devel.config_edit', array('config_name' => $config_name)),
+ 'query' => $destination
+ );
+ $rows[] = array(
+ 'name' => $config_name,
+ 'operation' => array('data' => array('#type' => 'operations', '#links' => $operations)),
+ );
+ }
+
+ $form['variables'] = array(
+ '#type' => 'table',
+ '#header' => $header,
+ '#rows' => $rows,
+ '#empty' => $this->t('No variables found')
+ );
+
+ return $form;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function submitForm(array &$form, FormStateInterface $form_state) {
+ $filter = $form_state->getValue('name');
+ $form_state->setRedirectUrl(Url::FromRoute('devel.configs_list', array('filter' => Html::escape($filter))));
+ }
+
+}