Clarify which block or section is being removed in layout builder dialog

@andrewmacpherson thanks for filing this. I can see the problem now.

I think adding more to the title would be cut off. Right now it looks like the question is being cut off.

Could we do this?

1. Change the dialog title to "Remove Section/Block"
2. inside the dialog add the question "Are you sure you want to remove [specific label for section or block]"?
3. The current "This action cannot be undone." would under this question.

Here's an initial patch.

Here's the test.

It's not clear why the "question" part (which is usually pretty standard across confirmation forms) is being shortened. Maybe it will be clear from screenshots?

Added screenshots.

@bendeguz.csirmaz thanks for the patch!

Just a few points

1. +++ b/core/modules/layout_builder/src/Form/RemoveBlockForm.php
   @@ -27,10 +30,50 @@ class RemoveBlockForm extends LayoutRebuildConfirmFormBase {
   +    return $this->t('Remove Block');
   

   I guess we should put a ? on the end since this is still supposed to be a question.

2. +++ b/core/modules/layout_builder/src/Form/RemoveBlockForm.php
   @@ -27,10 +30,50 @@ class RemoveBlockForm extends LayoutRebuildConfirmFormBase {
   +    return $this->t('<p>Are you sure you want to remove Block @admin_label?</p><p>This action cannot be undone.</p>', ['@admin_label' => $definition['admin_label']]);
   

   I don't think we should using the block plugin admin label here. If we do then blocks that have derivatives will all have the same label.

   Instead since all blocks in the layout builder have to have a label in the configuration I think we should get the label that user entered.

   Also "Block" here does not need to be capitalized..

   Maybe also change the order to
   Are you sure you want to remove the [label] block?

3. +++ b/core/modules/layout_builder/src/Form/RemoveSectionForm.php
   @@ -23,7 +23,14 @@ public function getFormId() {
   +    return $this->t('Remove Section');
   

   add ?

4. +++ b/core/modules/layout_builder/src/Form/RemoveSectionForm.php
   @@ -23,7 +23,14 @@ public function getFormId() {
   +    return $this->t('<p>Are you sure you want to remove Section @delta?</p><p>This action cannot be undone.</p>', ['@delta' => $this->delta]);
   

   since the delta starts a 0 this will display "Section 0" we should +1 to the delta when displaying.

re #8
I guess we don't have to shorten the question. I just wonder about adding more text to it, the block label, since it is already being cut off.

Maybe we could leave the question and then just add detail about which block will be removed in the description?

1) "Remove Block" is wrong, it would be "Remove block" (sentence case)

2) Is this trying to work around #3037124: Off-canvas dialog titles should not be visually truncated as well?

In the other parts of Layout Builder, we add the section number but visually hide it. And we use 1-indexed numbers not 0-indexed.

// Add one to the current delta since it is zero-indexed.
'#title' => $this->t('Add Block <span class="visually-hidden">in section @section, @region region</span>', ['@section' => $delta + 1, '@region' => $region_labels[$region]]),

From #3013770: Distinguish between the repeated text of buttons in Layout Builder UI

Thanks for the review and guidance @andrewmacpherson!

1. +++ b/core/modules/layout_builder/src/Form/LayoutRebuildConfirmFormBase.php
   @@ -42,7 +42,7 @@
   -   * Constructs a new RemoveSectionForm.
   +   * Constructs a new LayoutRebuildConfirmFormBase.
   

   Fair change, but out of scope

2. +++ b/core/modules/layout_builder/src/Form/RemoveBlockForm.php
   @@ -30,7 +30,13 @@ class RemoveBlockForm extends LayoutRebuildConfirmFormBase {
   +    return $this->t('Are you sure you want to remove the @label block?', ['@label' => $label]);
   

   Please use %label here to help differentiate it from the rest of the sentence

This looks after #16 addressed

re #16.2 the html will actually be stripped out in the off-canvas but I guess it can hurt if if used outside the dialog
Add screenshots of current patch to issue summary and also manually tested.

Great work, everyone! Love these accessibility wins!

Committed and pushed to 8.7.x. Thanks!