Provide single field values from multivalue fields as layout builder-friendly blocks

Here a version of the patch that works on 10.1

rhovland → changed the visibility of the branch 11.x to hidden.

rhovland → changed the visibility of the branch 10.1.x to hidden.

rhovland → changed the visibility of the branch 3029830-field-block-offsets to hidden.

The old branch was empty so I made a new one based on 11.x

There's one test failure but it doesn't seem like it's related to these changes?

I haven't done a comprehensive review of this yet since it's not green, but does the test need to be FunctionalJS? I think we can just do a Functional test here

I think that the patch #44 has a bug. If you set a field with “Number of items to display = 0”, when you reach to the second "if”, the condition will be FALSE and will not hide unwanted fields.

if ($items_to_display = (int) $block_configuration['items_to_display']) {

      // If this is a multi-value block configured to not display all values,
      // remove those field items from the render array.
      $block_configuration = $block->getConfiguration();
      if (!$is_content_empty && isset($block_configuration['display_items']) && $block_configuration['display_items'] == 'display_some') {
        if ($items_to_display = (int) $block_configuration['items_to_display']) {
          $offset = (int) $block_configuration['offset'];
          $range = range(0, $content[0]['#items']->count());
          foreach ($range as $key) {
            $top_range = $offset + $items_to_display - 1;
            if ($key < $offset || $key > $top_range) {
              $content[0][$key]['#access'] = FALSE;
            }
          }
        }
      }

I can confirm that bug. Also I wanted to mention that this particular solution will be a bit difficult to use, especially in the case that there are a lot of deltas in field. I wonder if it makes sense to also display the index of each delta in the preview to make it easier to select the values you are looking for

I went ahead and made a small change to patch #44 (I made against 10.3.x), which addresses both the bug and my need for an index to be displayed. I am happy to take any feedback, and if people like I can update the issue fork too. I pretty much just touched the code mentioned in #51.

Potential improvements to make on #53:

• make indices always display, even when offset and items to display are both 0
• Add block configuration to control whether the indices should be shown in the preview

Sorry #53 was still buggy, so ignore that one. This new one is what I meant for #53 to be. I did not make any improvements mentioned in #54. Again, this patch is for 10.3.x, but if the changes are agreeable, happy to commit them into the fork.

Oops I didn't realize that the changes I made affected things outside of preview mode. One more fix to make sure my index strings only show up in preview mode.

Okay one thing I really don't like about this implementation is that when you change the order of the deltas in the edit form, including when you delete a value, the items that you have displayed in the layout change.

But I acknowledge that this might be a feature for some people.

Left comments on MR.

I ran testBlockAccess locally and it passed. The CI says that it failed:

https://git.drupalcode.org/issue/drupal-3029830/-/jobs/3186760