Hello, I'm working on a mod that has world-specific data and I am trying to save/load it using my class that extends WorldSavedData.

Currently, my mod properly creates, loads, edits, and saves world data when I test the mod on a MP server. When I test it in SP, my mod properly creates, loads, and edits world data, but it does not save the world data as it should.

I tested this by conducting a few experiments:

1. properly creates Mod/saves/test_world/data/<DATA_NAME>.dat file when there isn't one

2. properly loads world data (in this case I copied a properly changed .dat file from the MP location to SP location to test this)

3. properly edits world data (i.e. change variable saved in my class that extends WorldSavedData)

4. DOES NOT properly save world data to the .dat file (i.e. changed values in WorldSavedData do not persist when world is closed and reopened)

Multiplayer

1. properly creates Mod/world/data/<DATA_NAME>.dat file when there isn't one

2. properly loads world data

 

3. properly edits world data (i.e. change variable saved in my class that extends WorldSavedData)

4. properly saves world data to the .dat file (i.e. changed values in WorldSavedData persist when server is closed and reopened)

Single-Player

 

The class that extends WorldSavedData for reference:

 

 

public class MobEventsWorldSavedData extends WorldSavedData {

private static final String DATA_NAME = "MobEvents";

<snip> //variables

 

public MobEventsWorldSavedData() {

super(DATA_NAME);

                <snip> //initialize variables

}

 

public MobEventsWorldSavedData(String name) {

super(name);

<snip> //initialize variables

}

 

public static MobEventsWorldSavedData get(World world) {

MapStorage storage = world.getPerWorldStorage();

MobEventsWorldSavedData instance = (MobEventsWorldSavedData) storage.loadData(MobEventsWorldSavedData.class, DATA_NAME);

 

if (instance == null) {

instance = new MobEventsWorldSavedData();

storage.setData(DATA_NAME, instance);

}

return instance;

}

 

@Override

public void readFromNBT(NBTTagCompound nbt) {

<snip> //this works properly

}

 

@Override

public void writeToNBT(NBTTagCompound nbt) {

<snip> //this works properly

}

}

 

 

Extra Information:

- MobEventsWorldSavedData.get(<world>) is called when the world loads in dimension 0

- <MobEventsWorldSavedData instance>.markDirty() is called after any variable is changed

 

If you have any idea why world data is not being saved properly in SP, please let me know! Thanks!

https://mcforge.readthedocs.io/en/latest/datastorage/worldsaveddata/

Did you read the documentation?

Yes I did, that's where I got most of the information about world data from for this. Is there something on there that I missed that I'm not seeing?

Could you show where you call your MobEventsWorldSavedData?

Could you show where you call your MobEventsWorldSavedData?

The world data is first created here and put in the Event.worldData variable:

        @SubscribeEvent(priority=EventPriority.NORMAL, receiveCanceled=true)
public void onEvent(WorldEvent.Load event)
{
	if (event.world.provider.getDimensionId() == 0)
		Event.worldData = MobEventsWorldSavedData.get(event.world);
}

 

The variables in Event.worldData are then used in many different places in my code, with Event.worldData.markDirty() being called afterwards if a variable is changed.

You should use the per world storage if you use different data for nether, end etc.!

That makes everything a little clearer if you try to save data per world!

You should use the per world storage if you use different data for nether, end etc.!

That makes everything a little clearer if you try to save data per world!

You're right, I had it with getPerWorldStorage originally and later changed it to see if it would fix this issue and forgot to change it back. It still has the same issue, but this is what MobEventsWorldSavedData get(<world>) looks like:

	public static MobEventsWorldSavedData get(World world) {
	MapStorage storage = world.getPerWorldStorage();
	MobEventsWorldSavedData instance = (MobEventsWorldSavedData) storage.loadData(MobEventsWorldSavedData.class, DATA_NAME);

	if (instance == null) {
		instance = new MobEventsWorldSavedData();
		storage.setData(DATA_NAME, instance);
	}
	return instance;
}

I'll fix this in the main post as well.

I'm not 100% sure now, but try to create a new instance of your data class everytime you try to load or save data instead of creating one field in your Event class!

And make sure that you call it on the server and the client side!

I'm not 100% sure now, but try to create a new instance of your data class everytime you try to load or save data instead of creating one field in your Event class!

And make sure that you call it on the server and the client side!

I replaced all instances of Event.worldData with MobEventsWorldSavedData.get(<world>) and it worked, thank you so much!