Error when using collections with EXT:content_blocks

[seirerman]

[multicolumn.zip]

I'm in the process of migrating content elements from EXT:mask to EXT:content_blocks because mask will be obsolete with TYPO3 14, and ran into an error/bug with content_defender.
I ran the migration script from nhovratov/mask-to-content-blocks to create the necessary files for all mask elements. After some minor tweaks the migrated content blocks usually work without any issues.

One of my content_blocks content elements has a "collection" ("repeating>content" in the mask GUI) where you can add multiple other content elements of certain types.
You can define a list of allowed record types in the config.yaml of the content block:

fields:
  -
    type: Collection
    identifier: tx_mask_multicolumn_1
    ...
    allowedRecordTypes:
      - text
      - textpic
      - header
      - image
      - uploads
      - shortcut

If an editor tries to add some content elements other than text or header, an error from content_defender is shown:

1: The record "" couldn't be saved due to disallowed value(s).

I'm not sure why text or header is possible, while the other record types are not. All types are in the content_defender TS config:

...
                allowed {
                  CType = header, text, textpic, image, table, uploads, shortcut, list, div, html, form_formframework
                }
...

For some reason content_defender interferes with content elements inside content_block content elements.
This didn't happen while using mask, because content_defender is only used for backend layouts (as far as I know).

Once content_defender is uninstalled, creating new uploads or image content elements inside the content block works again.

I'll attach the files of my content block, hopefully you can reproduce the error.:
(https://github.com/user-attachments/files/26140215/multicolumn.zip)

[seirerman]

You have to add this TypoScript to make the content block work in the frontend, but this is not really relevant to this issue because it only affects the TYPO3 backend:

lib.contentBlocks.content = RECORDS
lib.contentBlocks.content {
  tables = tt_content
  source.current = 1
  dontCheckPid = 1
}

[seirerman]

I copied the wrong TS from the backendLayout, sorry. allowed.CType was missing the CTypes textpic, image, uploads and shortcut, which explains the errors. After adding the values to the backendLayout, the errors were gone. But this is not really what I wanted, because no editors could create textpic content elements directly on that page, and not only inside the content_block using collections.

I understand that content_blocks uses colPos=0 for content elements inside collections, whereas mask used colPos=999. This results in a conflict between the allowed CTypes defined for colPos 0 and allowedRecordTypes within a content element collection, which also use colPos=0.

Maybe there is a way to check if the content element was created directly on a page, or inside a content_blocks collection?
In my case there is a field in tt_content called tx_mask_content_role which references the name of the collection field name tx_mask_multicolumn_1. Both values could be called anything (in my case they were just migrated from mask without renaming them), but both values are registered in the yaml config for the content blocks element and could be parsed from there:

    ...
    type: Collection
    identifier: tx_mask_multicolumn_1
    ...
    foreign_match_fields:
      tx_mask_content_role: tx_mask_multicolumn_1
    allowedRecordTypes:
      - text
      - textpic
      - header
      - image
      - uploads
      - shortcut
    ...

So basically "don't apply content_defender restrictions if content element has value of tx_mask_multicolumn_1 in tt_content field tx_mask_content_role".