Configuration form and submission handler

Question

I am using the following code for Drupal 6.

 foreach (variable_get('cleanupeditform_formkeys', 0) as $key => $value ) {     
    $form['cleanupedit_hide'][CLEANUPEDITFORM_HIDEPREFIX . $key] = array(      
      '#type' => 'checkbox',    
      '#title' => t('Hide ') . $value,    
      '#default_value' => variable_get(CLEANUPEDITFORM_HIDEPREFIX . $key , 1),
    );
  }

I need to convert this code to Drupal 8.

In buildForm() I generate the form. I need to save the checkboxes values, and I am using the following code.

public function submitForm(array &$form, FormStateInterface $form_state) {
     foreach ((\Drupal::state()->get('cleanupeditform_formkeys') ?: 0) as $key => $value ) {
       parent::submitForm($form,$form_state);
       $this->config('cleanupeditform.admin_settings')
         ->set('element', $form_state['cleanupedit_hide'][CLEANUPEDITFORM_HIDEPREFIX . $key])
         ->set('element', $form_state['cleanupedit_allow'][CLEANUPEDITFORM_ALLOWPREFIX . $key])
         ->save();
     }
     parent::submitForm($form, $form_state);
  }

Please help me to find out a solution.

Answer 1

There are the following errors in that code:

• You call parent::submitForm($form, $form_state) inside the foreach() loop, when it should be called once, outside the loop
• You keep setting element, which means you are only saving a single value
• Your code is still accessing the FormStateInterface object as an array, as it was done in Drupal 7

I cannot comment about the \Drupal::state()->get('cleanupeditform_formkeys') part, except that I would probably inject the service as dependency, but I would rather use the following code.

public function submitForm(array &$form, FormStateInterface $form_state) {
  foreach ((\Drupal::state()->get('cleanupeditform_formkeys') ?: []) as $key => $value ) {
    $this->config('cleanupeditform.admin_settings')
      ->set(CLEANUPEDITFORM_HIDEPREFIX . $key, $form_state->getValue(CLEANUPEDITFORM_HIDEPREFIX . $key))
      ->set(CLEANUPEDITFORM_ALLOWPREFIX . $key, $form_state->getValue(CLEANUPEDITFORM_ALLOWPREFIX . $key))
      ->save();
  }
  parent::submitForm($form, $form_state);
}