Fix: What can I use as the default value in com_fields field imagelist

[ReLater]

Pull Request for Issue #15173

Summary of Changes

• After comparing the issue with behavior of com_fields field media that extends FieldsPlugin but not FieldsListPlugin like imagelist does:
• • Using FieldsListPlugin leads to validation via OptionsRule.php because line https://github.com/joomla/joomla-cms/blob/staging/administrator/components/com_fields/models/field.php#L261 returns a type=options instead of imagelist.
    (In media field the $type = media.)
• • There are no options in the element whwn you create the field. Thus the validation always fails.

Testing Instructions

• Please read comment [com_fields] What can I insert as the default value of the field imagelist #15173 (comment)

Expected result

• Field can be saved.
• You can select an image in articles and the default value is respected when you don't select another one.
• Image is displayed in frontend in article view.

Actual result

• Field can't be saved when you fill the Default Value field because validation fails.

@laoneo please check.

[ghost]

@astridx @joomdonation can you please test?

[ReLater]

No tests.
No comments of pinged experts here and in > 2 years old issue.
TBH i never use com_fields.
Closing.

[infograf768]

I tested this patch OK here.
See #26350 (comment)

Please @ReLater can you reopen?

[infograf768]

No time to wait if we want to get this in for 3.9.12
Thanks @ReLater I have redone the patch here #26352

[EJBJane]

I have made 4 screenshots here to show the process. I have purged the cache now also at CDN level and turned it off. The problem of the default image not showing up in frontend persists with me, however the validation error is now solved with patch #26352 .

screencapture-1-field.pdf
screencapture-2-field.pdf
screencapture-3-field.pdf
screencapture-4-field.pdf

[infograf768]

@EJBJane
Please now post in #26352
Looks like your display problem is not related to Joomla core.
The test is to be done with Protostar and default com_content

[EJBJane]

okay get it