Howdy everyone. I've been messing around with some oop stuff and ran into something that has me scratching my head. I can successfully call a static method from a class without instantiating an object of that class as advertised. However, whenever I try to call a static method from an abstract class, CF blows up and states that it can't create the abstract component. This is confusing to me since I'm calling a static function which by definition shouldn't need to create an instance. So calling a static method works until I define the class I'm calling it from as abstract. Not sure what I'm missing.

Probably just a bug. I'd enter a ticket 🙂

Happening for both ACF and Lucee.

have you tried lucee 5.3.10.84 it contains some more static fixes

ACF 2021 Update 5. Lucee 5.3.9

Happening for both ACF and Lucee.

Ugh.

states that it can't create the abstract component

Double ugh

I'm not too surprised. Both static and abstract are fairly recent features which underwent very little public testing and don't get used that much.

Confirmed I am seeing same as Joe:

// AbstractBase.cfc
abstract component {

    public static function f(){
        return "hi"
    }

}

// testAbstractBase.cfm
writeOutput(AbstractBase::f())

If I create a ConcreteImplementation.cfc and extend AbstractBase and call

ConcreteImplementation::f()

it works fine

Just tried Lucee 5.3.10.84 and it has the same issue still.

I'm just glad to see a CFMLer using (or at least trying to...) abstract and static functionality.

Well, I've been walking through the examples in Kent Beck's Test Driven Development and was doing just fine using CF and Testbox to recreate them. That is until one example called a static method from an abstract class lol.

From the Adobe docs: https://helpx.adobe.com/coldfusion/developing-applications/building-blocks-of-coldfusion-applications/object-oriented-programming-coldfusion.html

An abstract component can have abstract method without body and can also have methods with implementation.

Use the abstract keyword to create an abstract component and method. In ColdFusion, you cannot instantiate an abstract component. An abstract component is mostly used to provide base for sub-components. The first concrete component should have the implementation of all the abstract methods in its inheritance hierarchy.

@cfvonner Not sure how that doc is relevant here? Static methods don't (shouldn't!) require instantiating the class. ACF (and Lucee) are just broken here.

I was just referring to the issue of not being able to instantiate an abstract component. It was not entirely clear to me which of the issues mentioned above was the "bug" - if it was that an abstract component couldn't be instantiated, then it is behaving as designed. If the bug was the issue with the combination of "static" methods and "abstract" components, then I guess it isn't relevant. Is it common in the non-CFML world to use "abstract" classes that contain "static" methods that are intended to be called without instantiating the class?

Static methods are, by definition, called without instantiating the class. So that's sort of a self-answering question 🙂

IMHO it's completely bullshit and not CFML-y that with statics that you need to reboot or touch a file to pick up changes. I will die in this hill

@bdw429s that's good info. As someone who has never done OO programming outside of CFML, I plead ignorance to how "static" is supposed to work in the wider world. The only Adobe doc that references static in CFCs that I could find was: https://helpx.adobe.com/coldfusion/developing-applications/building-blocks-of-coldfu[…]-and-using-coldfusion-components/cfc-variables-and-scope.html There is one example of calling a static method on a CFC without instantiating it (see Case3.cfc/Case3.cfm). It took me a couple passes of that page to notice that the calling code wasn't instantiating the compoent first:

Case3::splitFullName("John Doe"))

Static makes more sense to me in Java since a Class is an object of its own produced by a classloader. In CFML, a CFC name is just a string defining where on disk you may find a CFC if you wanted to look for it. Static members/methods are widely used in java to enforce a singleton pattern, using the class's static data as the "holding" pen for the singleton instance. Furthermore, it's common to see pure utility methods that require no state (like

Math.round( float a )

to be a static method so you can just import the class and call it directly.

I find (final) static properties useful, and occasionally static methods. Although I will say with the latter it's mostly been when I need to circumvent CFWheels object-instantiation shitfuckery, rather than any masterful design on my part. As far as abstract stuff goes... not something I use that often but I figure better to have and not need, than need and not have. If I was in the habit of building general libraries intended to be used by third parties, I'd probably want to stick to familiar OOP concepts for the same reason I'd stick to familiar design patterns: it communicates intent in a generally understood way (*). Given CF supports default implementations on interface methods, abstract seems to be a bit of a lemon though, dunnit? They're kinda two ways of skinning the same cat? And designing-to-an-interface is more zeitgeisty than overbaking inheritance, I think. (*) this is a theory that collapses pretty quickly in the CFML world, granted. But I think this is more a shortcoming of the CFML world than the industry-accepted approaches, I think.

It's fine to take inspiration from other languages but Adobe's main problem is that they're usually tried to copy features from Java/Script and just get it wrong and don't even think about whether it makes any sense to have said features in a dynamically typed, compile-on-demand language.

reckon we can still accommodate everyone

We have

onMissingMethod()

because I pushed for it -- because Ruby and Smalltalk have something very similar. And that makes sense in a dynamic OOP language.

the static inheritance problem in lucee was fixed in 5.3.10.81 https://luceeserver.atlassian.net/browse/LDEV-4212

@zackster No one is talking about "static inheritance".

until it bytes (sic) them in the bum, i figure such information is useful to share isn't it?

Created https://tracker.adobe.com/#/view/CF-4215583 for ACF.

I check the lucee jira too, feel free to file a bug

Thanks, @zackster. Bug filed.

cheerz