public function rule_bool($a)
    {
        // We don't use PHP inbuilt test - a bit restrictive

        // Changes PHP true/false to 1, 0
        $a = strtolower($a);

        $vals = array('true', 'false', 't', 'f', 1, 0, 'yes', 'no', 'y', 'n');

        if (!in_array($a, $vals)) {
            return $this->fail('Must be a boolean value');
        }
    }
public function rule_bool($a)
    {
        // We don't use PHP inbuilt test - a bit restrictive

        // Changes PHP true/false to 1, 0
        $a = strtolower($a);

        $vals = array('true', 'false', 't', 'f', 1, 0, 'yes', 'no', 'y', 'n');

        if (!in_array($a, $vals)) {
            return $this->fail('Must be a boolean value');
        }
    }
public function rule_bool ( $ a ) { // We don't use PHP inbuilt test - a bit restrictive // Changes PHP true/false to 1, 0 $ a = strtolower ( $ a ) ; $ vals = array ( 'true' , 'false' , 't' , 'f' , 1 , 0 , 'yes' , 'no' , 'y' , 'n' ) ; if ( ! in_array ( $ a , $ vals ) ) { return $ this -> fail ( 'Must be a boolean value' ) ; } }
Validate for true|false|t|f|1|0|yes|no|y|n.

Normalizes to lower case
Validate for true|false|t|f|1|0|yes|no|y|n .