It checks for the existence of (and creates) the world directory if it doesn't exist. But what sense does this make when the world obviously doesn't exist in this case and must be generated first?
This is problematic because child level providers can forget to override the provider name of their parents, and then override them by error. Instead, they should be used in a mapping fashion to make sure they are unique and not inherited.
Also, the old method did not permit registering multiple aliases for the same provider. This now makes that possible.
This is a significant breaking change for anything utilizing Tiles as they now do not store their NBT at runtime anymore.
This is another step in the process of ridding PocketMine-MP of runtime NBT.
It can be noticed that all tiles are now using class fields to store properties instead of NBT, which is much faster, uses less memory and is also more concise when written in code.
Highlights:
- Tile->namedtag has been removed.
- Tile->saveNBT() now accepts a CompoundTag() parameter. Typically it's expected that this will be fed a newly-created CompoundTag (this part may be improved in the future).
- New internal methods Tile->readSaveData() and Tile->writeSaveData() have been added. Instead of overriding __construct() and saveNBT() to load and save properties from NBT, you should now implement these methods instead.
This is not final and will see further changes before it's done.
This now removes logging from the level providers (for the most part) and replaces it with exception throws and catches. The implementation using the providers should catch these exceptions if they are thrown.
Level providers are now cut back to just an interface to a world's data. They don't keep their own chunk registries or any stupid shit like that because the Level already does that.
This furthers the goal of being able to move level I/O off the main thread, and also drastically decreases the complication of implementing level providers.
The remaining methods, constants and fields in the NBT class now pertain to generic NBT functionality (except for the matchList()/matchTree() methods, but that's a job for another time). All NBT I/O specific logic has now been moved to NBTStream and its descendents.
Always register the level provider (to allow detecting the world format) but throw exceptions if anything tries to use it without the extension being loaded.
