Show warning when comment field is about to be deleted

Is this issue actual?

Yes, it still makes sense to warn user about deletion of all comments the deleted field provides

@masipila I think to make a generic deletion message for all fields make more sense and easiest to do. Deletion question is coming from Drupal/Core/Entity/EntityDeleteFormTrait::getQuestion() and description is coming from Drupal/Core/Entity/EntityConfirmFormBase::getDescription() We can simply change getDescription to return warning as well.

To make Comment module specific warning will require more work and testing. Thoughts?

Simplest possible solution.

The patch applies cleanly. The changes made are sufficient.

no-go for global override, probably comment module should alter \Drupal\field_ui\Form\FieldConfigDeleteForm when comment field is deleted

@andypost This is not a global override. We are modifying the global field delete message and adding a warning to the message, which kind of make sense to show a warning that If you delete this field all the content of this field are going to be deleted permanently. Thoughts?

Can you please give input on how can comment module alter \Drupal\field_ui\Form\FieldConfigDeleteForm if comment field is being deleted. There is a \Drupal\comment\Form\CommentTypeDeleteForm but this is for comment type deletion.

Screenshot after applying this patch.

@msankhala thanx, now check delete form for any other field...

That's why I suggest to override comment delete form only to point that only comments from this field will be deleted
Basically not every field will delete some entities - guess paragraphs will need that as well)

+++ b/core/lib/Drupal/Core/Entity/EntityConfirmFormBase.php
@@ -24,7 +24,7 @@ public function getBaseFormId() {
-    return $this->t('This action cannot be undone.');
+    return '<p>' . $this->t('<strong>Warning:</strong> All the contents of this field will be deleted permanently. This action cannot be undone.') . '</p>';

what is "All the contents" means in scope of any field?

@andypost I think 'All the contents' is not that confusing because if you are deleting a field then definitely all the contents of that field are going to be deleted, no matter what kind of field is that.
But I am happy to override this message only for comment field. I'll need your help in this. Do we need a new class something like \Drupal\comment\Form\CommentFeildConfigDeleteForm which will extend \Drupal\Core\Entity\EntityDeleteForm? or there is any better approach?

@msankhala I think better to add hook form_id alter cos you need to change only a message for specific condition

Here is a new patch to display warning message specific to comment field deletion. Do we really need a test for this? We can create another issue to test this.

I made the interdiff for the patches 8 and 21.

@msankhala

I was test patch #21 , It is little confused

1. create a article and submit comment
2. git apply comment-field-delete-form-warning-2908607-21.patch
3. delete field comment from article type
4. goto comment manager page /admin/content/comment

You will see the comment still here but clicking the comment link leads to errors. The actual situation is inconsistent with the description.

@dravenk Thanks for reviewing. Yes as @masipila mentioned actual comment not being deleted is related to another issue. The scope of this issue is only showing the proper warning message on comment field delete form.

@masipila
Thank you for finding the reason. Now that looks good.

@masipila I think this has no dependency on the related issue, this is only about showing the warning. I think this can be committed. No?