Fix SelectFromList retrieving behaviour

[MohamedAsli]

Description

Fixes multiselect bug in SelectFromList where only selections from the currently active group were returned, losing selections from other groups.
This behavior seems unintended, as there's no logical reason for selections to be lost when switching between groups.

What I've changed:

• Added _get_all_ctx() helper method to return items from all groups
• Modified _get_options() to use _get_all_ctx() instead of _get_active_ctx() in multiselect mode
• Preserves existing behavior for non-grouped contexts and single-select

No regressions detected as far as I tested

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Checklist

• Code follows the PEP 8 style guide.
• Code has been formatted with Black
• Changes are tested and verified to work as expected.

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Related Issues

#2286

[devloai]

PR Summary:

Fixes multiselect bug in SelectFromList where only selections from the currently active group were returned, losing selections from other groups. Adds _get_all_ctx() helper method and modifies _get_options() to use it instead of _get_active_ctx() in multiselect mode.

Review Summary:

The fix correctly addresses the reported issue and the implementation is technically sound. However, this introduces a breaking change that contradicts explicit maintainer guidance from issue #2286, where @sanzoghenzo recommended implementing this via an optional parameter to maintain backward compatibility. The current approach changes default behavior for existing users.

Follow-up suggestions:

• @devloai implement backward compatibility using an optional parameter as suggested by the maintainer
• @devloai add the new parameter to class docstring and setup method

[MohamedAsli]

Got inspired by @onomou's snippet, with a minor difference :

we always should use _get_all_ctx() even if return_all == false, because this argument is only meant to return all items values even if they are unchecked, in order to get their respective states.

[sanzoghenzo]

Devlo misunderstood things a little, here's my two cents...

[MohamedAsli]

@jmcouffin should we merge this ?

[jmcouffin]

@MohamedAsli If you resolved the latest comment from Andrea, yes

[MohamedAsli]

Sorry for the late reply, I got sidetracked, then forgot about the remaining modification

[sanzoghenzo]

My focus on pythyon 3.10+ collides with pyRevit 😅 We can ignore my last comment and proceed with the merge!

[MohamedAsli]

Your comment came in just as I pushed my commit :)
We can include the generator anyway now that it's done