protected function explodeField($field)
    {
        $parts = explode('.', $field);

        if (count($parts) == 2) {
            return $parts;
        }

        throw new RuntimeException(sprintf(
            'Invalid field specification, '.
            'expected string like "[alias].[field_name]", got "%s"',
            $field
        ));
    }
protected function explodeField($field)
    {
        $parts = explode('.', $field);

        if (count($parts) == 2) {
            return $parts;
        }

        throw new RuntimeException(sprintf(
            'Invalid field specification, '.
            'expected string like "[alias].[field_name]", got "%s"',
            $field
        ));
    }
protected function explodeField ( $ field ) { $ parts = explode ( '.' , $ field ) ; if ( count ( $ parts ) == 2 ) { return $ parts ; } throw new RuntimeException ( sprintf ( 'Invalid field specification, ' . 'expected string like "[alias].[field_name]", got "%s"' , $ field ) ) ; }
Return the alias name and field name
from the given string of form.

[alias].[field_name]

e.g. my_alias.first_name

@param string $field

@return array
Return the alias name and field name from the given string of form .