Re: protected abstract static function ... E_STRICT

Johannes Ott wrote: > why PHP in Strict mode fires as warning for the declaration of a > abstract function: Good question! Having abstract static functions without late static binding doesn't make sense, but that "feature" has been introduced with PHP 5.3.0. See also an respective RFC draft[1], which proposes to remove the E_STRICT for this case. > What I want to do is: > > > abstract class Scalar { > > protected $value; > > public function __construct($value) { > if (static::valid($value)) { > $this->value = $value; > } else { > throw new RuntimeException(); > } > } > > /** each child has to have it's own function */ > protected abstract static function valid($value); > } > > final class Integer extends Scalar { > > protected static function valid($value) { > return is_int($value); > } > } > > final class Float extends Scalar { > > protected static function valid($value) { > return is_float($value) || is_int($value); > } > > } > > The abstract superclass has no need implement the valid function but the > childclasses have to. > > What I'm having as workaround at the moment: > > abstract class Scalar { > > ... > > protected static function valid($value) { > throw new BadMethodCallException('Method should be only called > in subclass'); > } > > } > > Any better solutions for this? I would suggest to rename the wording, to make it clear that a subclass has to implement this method -- it's not so much about the caller. An alternative might be to disable E_STRICT while the function is being compiled. However, I would probably prefer to make the constructor abstract, or to use a dynamic method isValid(). [1] <https://wiki.php.net/rfc/reclassify_e_strict#abstract_static_methods> -- Christoph M. Becker