Remove usage of deprecated AsChannelFirst, AddChannel , and SplitChannel

[bhashemian]

Fixes #6280

Description

This PR removes the usage of AsChannelFirst, AddChannel, and SplitChannel (which are deprecated since v0.8) and add removed version to v1.3.

Types of changes

• Non-breaking change (fix or new feature that would not break existing functionality).
• Breaking change (fix or new feature that would cause existing functionality to change).
• New tests added to cover the changes.
• Integration tests passed locally by running ./runtests.sh -f -u --net --coverage.
• Quick tests passed locally by running ./runtests.sh --quick --unittests --disttests.
• In-line docstrings updated.
• Documentation updated, tested make html command in the docs/ folder.

[Nic-Ma]

Hi @ericspod @drbeh ,

May I know the latest status and plan for this PR?

Thanks.

[ericspod]

Hi @ericspod @drbeh ,

May I know the latest status and plan for this PR?

Thanks.

I think @drbeh still wanted to work on this one to get the other old classes removed. I'm fine removing them so long as they are all gone from our tutorials and bootcamp materials. We could keep them as wrappers around the correct classes to use and set a deletion version as 1.3 if people aren't sure about removing now.

[bhashemian]

Hi @ericspod @drbeh ,
May I know the latest status and plan for this PR?
Thanks.

I think @drbeh still wanted to work on this one to get the other old classes removed. I'm fine removing them so long as they are all gone from our tutorials and bootcamp materials. We could keep them as wrappers around the correct classes to use and set a deletion version as 1.3 if people aren't sure about removing now.

That's right! We should make them as aliases but my question is do we really need to deprecate these aliases? Since they are aliases, the maintenance cost is very low. I am just wondering if we want to keep them to avoid unnecessary breaking changes. What do you think? @ericspod @Nic-Ma @wyli

[ericspod]

we really need to deprecate these aliases?

I'd say we should to push people towards the better practice of using the real transforms and not these aliases. Once we've had these in place for a version of two we can remove them safely, they are lightweight but less stagnant code is still better.

[ericspod]

Are we removing the classes entirely and no aliases?

[bhashemian]

Are we removing the classes entirely and no aliases?

@ericspod I am a bit unsure about the best way to do that. Can you help to find the best way to move forward?
Here are three options:

1. remove them entirely since they have already deprecated since 0.8, which follows the existing MONAI guideline.
2. create an alias as AsChannelFirst = EnsureChannelFirst, which would work but we should add it to the documentation too.
3. make AsChannelFirst a wrapper around EnsureChannelFirst and set another deprecation version for it, which is fine too but seems to be a bit arbitrary what version to put and also we should keep CI/CD for this wrapper.

[ericspod]

Thanks @drbeh, I'd say option 3 is the solution since we deprecated the class but didn't set a removal version. We can create a wrapper and set the removal for 1.3, meanwhile we can remove the documentation and tests as you've done and rely on the tests for EnsureChannelFirst.

If instead no one's worried about people using these classes we can go with option 1.

[bhashemian]

Thanks @drbeh, I'd say option 3 is the solution since we deprecated the class but didn't set a removal version. We can create a wrapper and set the removal for 1.3, meanwhile we can remove the documentation and tests as you've done and rely on the tests for EnsureChannelFirst.

If instead no one's worried about people using these classes we can go with option 1.

Sure, thanks, I'll update the PR accordingly.

[bhashemian]

@ericspod I made aliases (wrapper classes) for these deprecated classes, set removed to v1.3, and replaced all their usage in the test cases with the correct classes. However, I kept their specific unit tests to make sure that they continue working before removing them. It will give some time to the users to consider replacing these transforms and also to us to clean up their usage in the tutorials, bundles, and MONAILabel. Please take another look and let me know if you have any other comment. Thanks

[ericspod]

Looks good to me. Thanks! We should see if anyone else has any comments.

[bhashemian]

@wyli @Nic-Ma do you have any comment here?

[wyli]

/build