Autoloading namespace constants and functions

php.internals

Chuck Hagenbuch

18 years ago
A few different proposals have mentioned the possibility that import or use statements might trigger autoload. My initial reaction is that this would be bad, BUT: it could let us use autoload to handle namespaced function libraries and namespace constants also - as long as they were imported. Which would be good. The missing piece would be allowing autoload to trigger when a fully-qualified name was used whether that name was for a function, class, or constant. In other words, I'd like autoload to kick in when I do this: <?php $stuff = My::Namespace::do_stuff(); ?> ... but let do_stuff be a function in the My::Namespace namespace, not a class method of the Namespace class in the My namespace. Right now as far as I can see autoload will trigger for this situation, but it will fail because after autoload finishes because My::Namespace wasn't declared as a class. Same for accessing namespace constants. Would it be possible to, after autoload runs, go back to seeing if the call is now resolvable, rather than assuming that a class had to be loaded? To try and fend off any "just don't use autoload" responses, the reason I want this to work is that if I can organize my libraries in a way that they are autoloadable, I can leave the decision on how code should be included up to the top-level application using the library. I can use an autoloader with development or when building a site, and then I can start including files explicitly - with no conditional includes and no _once usage - in a very opcode-cache friendly way, with no changes to the libraries or the rest of the app. I think that's a very desirable situation, and namespaces almost get us there - I just can't make full use of namespaced functions or namespace constants right now if I want to do it. -chuck

Stanislav Malyshev

18 years ago
> A few different proposals have mentioned the possibility that import or > use statements might trigger autoload.
I don't think it's a good idea. Import is a compile-time name transformation, it doesn't even have to be a name of any real class or namespace.
> The missing piece would be allowing autoload to trigger when a > fully-qualified name was used whether that name was for a function, > class, or constant.
That won't be autoload that we have now, but entirely different functionality, and I'm not sure many people would really need it.
> ... but let do_stuff be a function in the My::Namespace namespace, not a > class method of the Namespace class in the My namespace.
And how the engine is supposed to know which one do you mean?
> situation, and namespaces almost get us there - I just can't make full > use of namespaced functions or namespace constants right now if I want > to do it.
You can't autoload functions and constants - just as you couldn't before. That doesn't prevent you from using them - just as it didn't prevent you from using them before :)
-- Stanislav Malyshev, Zend Software Architect stas@zend.com http://www.zend.com/ (408)253-8829 MSN: stas@zend.com