Matrix field propagation method switch from none to siteGroup

[Megafry]

My customer asked whether the propagation method can be switched to siteGroup for the matrix field containing the content module.
I tested this locally, but after switching, all entries were duplicated across all languages.

Is there a way to merge the duplicated entries back together?
Does Craft store any metadata (such as a copy source ID) that could be used for this?

Thank you in advance for your help.

Best regards

[brandonkelly]

When the propagation method is set to none, each site gets its own unique set of nested entries. There is no relation between the nested entries in Site A and the nested entries in Site B, etc.

             │             
   Site A    │   Site B    
─────────────┼─────────────
┌───────────┐│             
│  Entry 1  ││             
└───────────┘│             
             │┌───────────┐
             ││  Entry 2  │
             │└───────────┘

When you change the propagation method to something else, each of those entries will be resaved across all of the sites they should now exist in. So an entry that previously only existed for Site A will now exist for Site A and Site B; and separately, an entry that previously only existed for Site B will now exist for Site B and Site A.

             │             
   Site A    │   Site B    
─────────────┼─────────────
┌────────────┴────────────┐
│         Entry 1         │
└────────────┬────────────┘
┌────────────┴────────────┐
│         Entry 2         │
└────────────┬────────────┘
             │             

So that explains why it might look like you now have 2x the content (or more, depending on how many sites are in the group).

Unfortunately there’s no built-in automated way to fix that, since these entries had no relation to begin with.

[Megafry]

Thanks for the feedback,
I have to check with my customer what the next steps will be.