fix: 404 error when creating subform

[lassopicasso]

Description

The 404 error occurred because the useCreateSubform hook was triggering the onSubformCreated callback before the new subform was saved on the backend. This caused a validation check in useSubformLayoutValidation to attempt accessing layouts for the new layout set too soon.

To address this, useCreateSubform now waits until the subform is successfully saved before calling onSubformCreated.

A spinner has also been added to indicate loading, improving the user experience, particularly for those with slower internet.

Below are videos from the two locations where users can create a subform, showing the spinner on a slow internet. @Annikenkbrathen, feel free to share any thoughts on the UX.

Video 1: Create subform in config

spinner-loading.mp4

Video 2: Create subform in subheader

spinner-loadingv2.mp4

Related Issue(s)

• 404 error received when creating a new subform #13967

Verification

• Your code builds clean without any errors or warnings
• Manual testing done (required)
• Relevant automated test added (if you find this hard, leave it and we'll help out)

Documentation

• User documentation is updated with a separate linked PR in altinn-studio-docs. (if applicable)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 95.21%. Comparing base (ceeaae8) to head (bb5f76c).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #13992   +/-   ##
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  Coverage   95.21%   95.21%           
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  Files        1756     1756           
  Lines       22984    22990    +6     
  Branches     2681     2684    +3     
=======================================
+ Hits        21885    21891    +6     
  Misses        849      849           
  Partials      250      250           

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[Annikenkbrathen]

Great to have a spinner to indicate loading/slowness! Eventually, we’ll remove the button at the top in video 2. So we probably don’t need to make any more changes there?

In the future, the user will only be able to add a subform from the component itself.

In the first video, I can’t actually see where the subform is being added. It’s supposed to appear in the config panel, under Component ID. But maybe that hasn’t been implemented yet or isn’t part of this task either?

[lassopicasso]

In the first video, I can’t actually see where the subform is being added. It’s supposed to appear in the config panel, under Component ID. But maybe that hasn’t been implemented yet or isn’t part of this task either?

It does appear in the config panel, but when a new subform is created, the user is automatically redirected to it. This might not be the intended behavior? If so, fixing it only requires removing one line of code (I think) 🙂 Edit: will fix it here #13999

[wrt95]

Lots of great code @lassopicasso 😄 Added some comments

[wrt95]

Great job 🤩

[nkylstad]

Tested ok, see comment in issue for details #13967 (comment)