Hey Carlton, in my opinion, the main use case would be to improve type safety, readability and to add a utility class for 3rd party packages. Someday, Django may add type hints and then this would be really beneficial.
In Django itself, the mentioned method css_classes <https://github.com/django/django/blob/main/django/forms/boundfield.py#L211-L222> does not offer any type safety; the passed in argument extra_classes can be None, a string containing a single CSS class or list containing those classes. By adding such a utility class, we can rewrite the above method to css_classes(extra_classes: ClassList): # optionally: extra_classes = ClassList(extra_classes) extra_classes.toggle(getattr(self.form, "error_css_class", None), self.errors) extra_classes.toggle(getattr(self.form, "required_css_class", None), self.field.required) return extra_classes which is much easier to read. In my project django-formset <https://github.com/jrief/django-formset>, I was able to remove a lot of boilerplate, by introducing that class. Naming that Python class ClassSet or CSSClassSet or CSSClasses might be a better option. I used ClassList because that's the name in JavaScript. – Jacob On Thursday, September 29, 2022 at 9:35:02 AM UTC+1 Carlton Gibson wrote: > Hey Jacob. Thanks for this. > > Can I ask you to give a few examples of potential usages in Django, and > showing the gain over use a set in these cases? > > I'm trying to imagine exactly what you have in mind, but I'm not entirely > clear. > > Thanks again. > Carlton > > On Friday, 23 September 2022 at 11:14:27 UTC+2 Jacob Rief wrote: > >> In JavaScript each HTMLElement has a property named classList >> <https://developer.mozilla.org/en-US/docs/Web/API/Element/classList>. >> This actually is a set allowing to *add* a single CSS class string, >> *remove* it >> and/or *toggle* it. >> >> If we would reimplement this as a Python class, methods such as >> css_classes >> <https://github.com/django/django/blob/main/django/forms/boundfield.py#L211-L222> >> >> could be implemented as a one-liner. This would also be beneficial >> for future uses of similar methods in Django and 3rd party libraries, >> because it is a quite >> common use case that one has to change the list of CSS classes as an >> element >> attribute. >> >> – Jacob >> > -- You received this message because you are subscribed to the Google Groups "Django developers (Contributions to Django itself)" group. To unsubscribe from this group and stop receiving emails from it, send an email to django-developers+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/django-developers/6d01cf69-23eb-4e8a-a13e-b29f26deab7an%40googlegroups.com.
