I’m working on a problem that requires that a vendor-specific module be loaded to handle vendor-specific tasks related to an order. I’ve been trying out the behaviours, and that all makes sense. Coming from an OO background, however, I’m feeling the need to have a factory in this case… where I wan…

FYI you could use the following to get module names from strings: my_module = "MyApp.VendorOne" module_atom = String.to_existing_atom("Elixir." <> my_module) module_atom == MyApp.VendorOne # true Edit: as indicated by others below (e.g. @sasajuric ’s), there are some better & safer approaches to th…

Using behaviour + @impl MyBehaviour above the callbacks will give the compiler the ability to help you if you get incorrect arity, or add an extra callback to the behaviour that your module doesn’t yet implement, for example.

Honestly, I don’t like the Factory pattern. I prefer to be a bit more data centric. For example, each vendor has it’s own way to understand the orders, so you should have something like %VendorOneOrder{}, %VendorTwoOrder{}, etc… and they you apply the processing implementing a Protocol (Processable…

The responses here are far more interesting than I expected! Thanks! Re passing the module name – to clarify, you are not passing a string representing the module name, right? handle_processing(MyApp.VendorOne) # <--- can work with module.process() as desc'd above # But the following won't work …

Mind. Blown. I hadn’t even considered this approach (because I hadn’t really grok’d protocols until I thought about it in this light).

[image] imetallica: Honestly, I don’t like the Factory pattern. I prefer to be a bit more data centric. ALL of the “classic” (i.e. Gang of Four) patterns are specific to statically-typed languages, and virtually disappear with idiomatic use of dynamically-typed languages. [image] fireproo…

[image] sribe: ALL of the “classic” (i.e. Gang of Four) patterns are specific to statically-typed languages, and virtually disappear with idiomatic use of dynamically-typed languages. Functional Programming For The Rest of Us Introduction Programmers are procrastinators. Get in, …

[image] david_ex: module_atom = String.to_existing_atom("Elixir." <> my_module) This has some pitfalls. it will only work if the module name already exist! Either by preloading all modules or by having it already used in another already loaded module. It relies on the (documented) implement…

[image] sribe: ALL of the “classic” (i.e. Gang of Four) patterns are specific to statically-typed languages, and virtually disappear with idiomatic use of dynamically-typed languages. Ehh, not really. The factory pattern is really a Java/C#'ism, not a static language thing. OCaml/Haskell/Et…

I definitely wouldn’t advise doing this, because it introduces a non-obvious coupling between the data in the database and the code. For example, if you refactor the code and don’t pay attention, the mapping is gone. Or even worse, some unwanted mapping might be introduced. Instead, I’d make it exp…

Elixir Programming Language Forum

Factory Pattern in Elixir?

Questions & Help Questions

StefanHoutzager February 12, 2019, 5:12pm 14

??? You mean the gof patterns are for oo (and indicate a smell).