MRO of DeleteView need to be changed.

[seokhun kim]

(Please refer to Pull Request-10362-Updated inheritance chain of the generic DeleteView)

I think MRO of DeleteView need to be changed in order to clarify the inheritance hierarchy.
So I refactored BaseDeleteView and DeleteMixin.

• (1) What is better as the super class of BaseDeleteView ?
  • Currently BaseDeleteView inherits from BaseDetailView.
  • I think SingleObjectMixin is sufficient.
  • I think Inheritance of Mixin is better than generic view itself.
  • So I deleted BaseDetailView in the super class of BaseDeleteView.
• In order to inherit SingleObjectMixin instead of BaseDetailView,
  • BaseDeleteView inherits from DeletionMixin.
  • DeletionMixin inherits from SingleObjectMixin.
• (2) Where is better on the location of get(), post(), delete() methods ?
  • Currently DeleteMixin provides those methods.
  • It is bad that Mixin class provides those methods, I think.
  • So My change is that BaseDeleteView provides get(), post() and delete() methods.

[seokhun kim]

Documentation exists in the Pull Request-10362-Updated inheritance chain of the generic DeleteView.

[Simon Charette]

Please don't mark you own tickets as Accepted, only someone else who believes the changes are adequate can do it.

I haven't investigated this in details but I'm a bit worried about changing the MRO and moving the methods off DeleteMixin for the sake of purity. Don't get me wrong, I think that these changes would make sense if we were to start from scratch but in this case I feel breakage risks outweigh the benefits.

See the ​ticket triaging documentation for more details.

[Carlton Gibson]

Replying to Simon Charette:

I haven't investigated this in details but I'm a bit worried about changing the MRO and moving the methods off DeleteMixin for the sake of purity. Don't get me wrong, I think that these changes would make sense if we were to start from scratch but in this case I feel breakage risks outweigh the benefits.

This seems right. I think for the breaking-change we have to close this as wontfix.

I'm not 100% on that. I've opened a ​django-developers thread asking for other opinions. Very happy to re-open if we think this is something we can do.

[seokhun kim]

You are saying "breaking-change".
However in my humble opinion, the code of DeleteView is not so difficult.
To speak simply, my change is using SingleObjectMixin instead of BaseDetailView.
I hope you can draw better conclusion through django-developers.
Anyway thank you for your review.

[Carlton Gibson]

You are saying "breaking-change".

The proposal removes methods from DeletionMixin, so if I'm relying on that, it clearly is a breaking change.

We might be able to work around that: the point of opening the discussion on django-developers was to put it in front of a wider audience, to make that decision better/easier. If you'd like to advocate this change there that would be great.

[seokhun kim]

I think you are good to open this ticket to django-developers.
My point is, I hope people don't be too serious to consider this ticket.
This is my first contribution and I don't have much experience.
So I think it's not good policy to advocate this. I believe you...~
Thank you, Carlton Gibson.