src/Config/Proxy.php
public static function parseBoolHelper($value)
    {
        $value = strtolower($value);
        if (in_array($value, array('true', '1', 'on', 'yes'), true)) {
            return true;
        }
        if (in_array($value, array('false', '0', 'off', 'no'), true)) {
            return false;
        }
        return null;
    }
public static function parseBoolHelper($value)
    {
        $value = strtolower($value);
        if (in_array($value, array('true', '1', 'on', 'yes'), true)) {
            return true;
        }
        if (in_array($value, array('false', '0', 'off', 'no'), true)) {
            return false;
        }
        return null;
    }
public static function parseBoolHelper ( $ value ) { $ value = strtolower ( $ value ) ; if ( in_array ( $ value , array ( 'true' , '1' , 'on' , 'yes' ) , true ) ) { return true ; } if ( in_array ( $ value , array ( 'false' , '0' , 'off' , 'no' ) , true ) ) { return false ; } return null ; }
Parses a text and tries to extract a boolean value.

\param string $value
The text from which a boolean should be extracted.

\retval bool
If a boolean could be extracted from the $value provided,
it is returned as the corresponding PHP boolean value
(either \b true or \b false).

\retval null
No boolean could be extracted.

\note
Currently, the following texts are recognized as \b true:
"true", "1", "on" & "yes", while the values
"false", "0", "off" & "no" are recognized as \b false.
The comparison is case-insensitive (ie. "true" == "TrUe").
Parses a text and tries to extract a boolean value .