I think UI is the least of their worries. They’ve not even decided what to migrate yet.
It really needs to be everything - posts, comments, subscriptions, upvotes/downvotes, blocks, and mod status. It needs to be such that signing in to your account on the new instance is the same as signing into on the old one. It should be so seamless that you can just switch instances just to try out a new one and switch back again if it isn’t for you.
It won’t be anything even close.
Indexes are unique to each instance. Post ID, Comment ID, Vote ID. There’s no way to correlate this information between two instances other than to do a full text match, post by post, comment by comment, vote by vote, to determine if what is being imported already exists on the new instance or is “new”.
Even if you go that route, then there’s the quandaries that follow… if you import what is effectively a “new” post to your new instance, do the comments (which aren’t yours) come along, or do you simply end up importing your post with no interaction history.
Then there is identity. You most likely have a non-local identity on your new server, as a result of federation, how does the new instance know that you are who you say you are, givimg you ownership of any of that existing content as it binds it to your, now, local identity?
That’s just off the top of my head.
If you’re lucky you’ll get to keep your cake day.
I kinda just want to keep my cake day. I signed up on my first account on my IRL birthday, but then I created my own instance some time later and created an account on that one. I just thought it was fun to have it on my birthday. :(
Indexes are unique to each instance. Post ID, Comment ID, Vote ID. There’s no way to correlate this information between two instances other than to do a full text match, post by post, comment by comment
I hope there will be a solution for this. It’s so unpractical. The only sane way to link to posts on other instances seems to be to cross-post them.
If you just share a link to a specific post or comment … people can see it, but unless they happen to have an account on that instance, they cannot interact with it. To do so, you have to search for it, and the search is not reliable.
Why can’t post or comment IDs be generated hashes, and each instance uses the same algorithm?
Posts and comments have a canonical URL (i.e. the original submission’s URL that’s linked to via the Fediverse pentagram), so that can be used as a foreign key when comparing.
I think identify claiming would need to have been designed into the original spec with something like a public/private key for account ownership to allow moving of related data in a safe way, or e.g. editing a post from a different instance than originally posted it.
As long as they’re using UUIDs where they should be the possibility of a collision is literally so low as to be impossible, but that relies on all the pieces of software using good principles.
It’s not that on mastodon and it shouldn’t be that here either. There needs to be some consequence to switching instance.
