[cakephp]ビットでフラグを持つ例

gistfile1.php

<?php
// View
$flags = array(
  pow(2,0) => 'フラグ1',
  pow(2,1) => 'フラグ2',
  pow(2,2) => 'フラグ3',
  pow(2,3) => 'フラグ4',
);
$checked = array();
foreach($flags as $k => $v) {
  if ($k & $user['User']['flag']) {
    $checked[] = $k;
  }
}
?>
<?= $form->input('User.flag', array('multiple' => 'checkbox', 'value' => $checked, 'options' => $flags, 'label' => false, 'error' => false)) ?>

<?php
// Controller
$save_data['User']['flag'] = array_sum($this->data['User']['flag']);