TabluarInline will not auto unhide/expand when classes = ['collapse'] and there is error during the saving process in django admin

[Jian]

For the admin.StackedInline and classes = collapse, it will auto add the red color border to the error field and the admin page will auto unhide/expand for the inline.

For the admin.TabularInline and classes = collapse, it will not add the red color border and the auto unhide/expand is not working.

[Carlton Gibson]

Hi Jian. This looks valid. Thanks for the report. Do you fancy trying to resolve it?

[Hasan Ramezani]

I checked it. There are 3 problems when there is an error during the save:

• admin.TabularInline will not show a red border
• admin.TabularInline will not expand
• admin.TabularInline and admin.StackedInline will not show Hide link when there is an error and formset is expanded

I am going to prepare a patch to address these 3 issues.

[Hasan Ramezani]

I created a ​PR to address the first two options.

[Carlton Gibson]

admin.TabularInline and admin.StackedInline will not show Hide link when there is an error and formset is expanded

I'm inclined to think we can leave that. That it's a feature: if there's an error don't let you collapse the inline, so you can't forget about it.
(No doubt X years from now, such ticket is opened... :)

I'm not 100% against but there's probably a better use of time.

[Carlton Gibson <carlton@…>]

In b4e7bf52:

Refs #31441 -- Added red border to inputs with errors for TabluarInline.

[Carlton Gibson <carlton@…>]

In 96c6f9c6:

Fixed #31441 -- Ensured TabluarInline expands when child inputs have errors.