uSyncMigrations - Collapse content type inheritance so they are standalone compositions

[ProNotion]

I have a site that I am migrating from v7. Currently I can't go straight from v7 > v12 but can go v7 > v10 > v12.

In the v7 site there is a content type with 2 ancestors which looks like this:

• BaseDoctype
  • | BaseMetaDoctype
    • | StandardContentPage

Is there any way that as part of the migration BaseDoctype can be moved down so that StandardContentPage is composed of BaseDoctype & BaseMetaDoctype instead of what currently happens where it retains the original hierarchy? The reason being is that I have a case where I need to retain the BaseMetaDoctype composition and drop the BaseDoctype for one particular content type.

Discussion also started on Discord

[ProNotion]

Proposed Solution - Feedback Required

1. Create Temporary Properties on Destination Content Type:
   Add temporary properties to the StandardContentPage content type that mirrors the properties from the BaseDoctype content type composition we want to move. This ensures that the properties will be available in the new content type. The temporary properties must not have the same properties aliases so suggest prefixing with temp_ or similar.

2. Copy Existing Data to Temporary Properties:
   Write a script to copy data from the BaseDoctype properties (currently in BaseMetaDoctype) to the temporary properties in StandardContentPage.

3. Remove BaseDoctype Composition from BaseMetaDoctype:
   Once the data is safely copied to StandardContentPage, remove the BaseDoctype composition from BaseMetaDoctype.

4. Add BaseDoctype composition directly to StandardContentPage:

5. Copy Data Back to BaseDoctype Properties:
   Write another script to copy the data from the temporary properties in StandardContentPage back to the appropriate BaseDoctype properties.

6. Remove the temporary properties from StandardContentPage.