Bundle/WidgetBundle/Builder/WidgetFormBuilder.php
public function convertToString($number, $letter = 'a', $i = 0)
    {
        if (!is_numeric($number)) {
            return $number;
        }

        while ($i < $number) {
            $i++;
            $letter++;
        }

        return $letter;
    }
public function convertToString($number, $letter = 'a', $i = 0)
    {
        if (!is_numeric($number)) {
            return $number;
        }

        while ($i < $number) {
            $i++;
            $letter++;
        }

        return $letter;
    }
public function convertToString ( $ number , $ letter = 'a' , $ i = 0 ) { if ( ! is_numeric ( $ number ) ) { return $ number ; } while ( $ i < $ number ) { $ i ++ ; $ letter ++ ; } return $ letter ; }
This method converts a number to an alphabetic char.
If the number is > 26, convert to aa...az...zz...

@param        $number
@param string $letter

@return string
This method converts a number to an alphabetic char . If the number is > 26 convert to aa ... az ... zz ...