--- /dev/null
+<?php
+
+namespace Drupal\devel\Form;
+
+use Drupal\Component\Serialization\Exception\InvalidDataTypeException;
+use Drupal\Component\Serialization\Yaml;
+use Drupal\Component\Utility\UrlHelper;
+use Drupal\Core\Form\FormBase;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Url;
+
+/**
+ * Edit config variable form.
+ */
+class ConfigEditor extends FormBase {
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getFormId() {
+ return 'devel_config_system_edit_form';
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function buildForm(array $form, FormStateInterface $form_state, $config_name = '') {
+ $config = $this->config($config_name);
+
+ if ($config === FALSE || $config->isNew()) {
+ drupal_set_message(t('Config @name does not exist in the system.', array('@name' => $config_name)), 'error');
+ return;
+ }
+
+ $data = $config->get();
+
+ if (empty($data)) {
+ drupal_set_message(t('Config @name exists but has no data.', array('@name' => $config_name)), 'warning');
+ return;
+ }
+
+ try {
+ $output = Yaml::encode($data);
+ }
+ catch (InvalidDataTypeException $e) {
+ drupal_set_message(t('Invalid data detected for @name : %error', array('@name' => $config_name, '%error' => $e->getMessage())), 'error');
+ return;
+ }
+
+ $form['current'] = array(
+ '#type' => 'details',
+ '#title' => $this->t('Current value for %variable', array('%variable' => $config_name)),
+ '#attributes' => array('class' => array('container-inline')),
+ );
+ $form['current']['value'] = array(
+ '#type' => 'item',
+ '#markup' => dpr($output, TRUE),
+ );
+
+ $form['name'] = array(
+ '#type' => 'value',
+ '#value' => $config_name,
+ );
+ $form['new'] = array(
+ '#type' => 'textarea',
+ '#title' => $this->t('New value'),
+ '#default_value' => $output,
+ '#rows' => 24,
+ '#required' => TRUE,
+ );
+
+ $form['actions'] = array('#type' => 'actions');
+ $form['actions']['submit'] = array(
+ '#type' => 'submit',
+ '#value' => $this->t('Save'),
+ );
+ $form['actions']['cancel'] = array(
+ '#type' => 'link',
+ '#title' => $this->t('Cancel'),
+ '#url' => $this->buildCancelLinkUrl(),
+ );
+
+ return $form;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function validateForm(array &$form, FormStateInterface $form_state) {
+ $value = $form_state->getValue('new');
+ // try to parse the new provided value
+ try {
+ $parsed_value = Yaml::decode($value);
+ // Config::setData needs array for the new configuration and
+ // a simple string is valid YAML for any reason.
+ if (is_array($parsed_value)) {
+ $form_state->setValue('parsed_value', $parsed_value);
+ }
+ else {
+ $form_state->setErrorByName('new', $this->t('Invalid input'));
+ }
+ }
+ catch (InvalidDataTypeException $e) {
+ $form_state->setErrorByName('new', $this->t('Invalid input: %error', array('%error' => $e->getMessage())));
+ }
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function submitForm(array &$form, FormStateInterface $form_state) {
+ $values = $form_state->getValues();
+ try {
+ $this->configFactory()->getEditable($values['name'])->setData($values['parsed_value'])->save();
+ drupal_set_message($this->t('Configuration variable %variable was successfully saved.', array('%variable' => $values['name'])));
+ $this->logger('devel')->info('Configuration variable %variable was successfully saved.', array('%variable' => $values['name']));
+
+ $form_state->setRedirectUrl(Url::fromRoute('devel.configs_list'));
+ }
+ catch (\Exception $e) {
+ drupal_set_message($e->getMessage(), 'error');
+ $this->logger('devel')->error('Error saving configuration variable %variable : %error.', array('%variable' => $values['name'], '%error' => $e->getMessage()));
+ }
+ }
+
+ /**
+ * Builds the cancel link url for the form.
+ *
+ * @return Url
+ * Cancel url
+ */
+ private function buildCancelLinkUrl() {
+ $query = $this->getRequest()->query;
+
+ if ($query->has('destination')) {
+ $options = UrlHelper::parse($query->get('destination'));
+ $url = Url::fromUri('internal:/' . $options['path'], $options);
+ }
+ else {
+ $url = Url::fromRoute('devel.configs_list');
+ }
+
+ return $url;
+ }
+
+}