system/controls/formcontrolcheckboxes.php

<?php

namespace Habari;

class FormControlCheckboxes extends FormControlSelect
{
  public function get(Theme $theme)
  {
    $checkboxes = $this->options;
    $control = $this;

    if(!is_array($control->value)) {
      $control->value = array();
    }
    array_walk(
      $checkboxes,
      function(&$item, $key) use($control) {
        $item = array(
          'label' => Utils::htmlspecialchars($item),
          'id' => Utils::slugify( $control->get_id() . '-' . $key ),
          'checked' => in_array($key, $control->value) ? 'checked="checked"' : '',
        );
      }
    );
    $this->vars['checkboxes'] = $checkboxes;
    $this->settings['ignore_name'] = true;
    return parent::get($theme);
  }


  public function process()
  {
    if(isset($_POST[$this->input_name()])) {
      $this->value = $_POST[$this->input_name()];
    }
    else {
      $this->value = false;
    }
  }

}

?>