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tutorial:persistent_states [2023/09/28 05:37] – Add missing imports jmanc3tutorial:persistent_states [2024/04/25 14:06] (current) – mayaqq
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 import net.minecraft.world.PersistentStateManager; import net.minecraft.world.PersistentStateManager;
 import net.minecraft.world.World; import net.minecraft.world.World;
-import net.minecraft.datafixer.DataFixTypes; 
  
 public class StateSaverAndLoader extends PersistentState { public class StateSaverAndLoader extends PersistentState {
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     // ... (Previously written code)     // ... (Previously written code)
  
-    public static StateSaverAndLoader createFromNbt(NbtCompound tag) {+    public static StateSaverAndLoader createFromNbt(NbtCompound tag, RegistryWrapper.WrapperLookup registryLookup) {
         StateSaverAndLoader state = new StateSaverAndLoader();         StateSaverAndLoader state = new StateSaverAndLoader();
         state.totalDirtBlocksBroken = tag.getInt("totalDirtBlocksBroken");         state.totalDirtBlocksBroken = tag.getInt("totalDirtBlocksBroken");
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 </code> </code>
  
-This function does the opposite of ''**writeNbt**''. It takes in an ''**NbtCompound**'' (the same one we wrote in ''**writeNbt**''), creates a brand ''**new StateSaverAndLoader**'' and stuffs it with the data inside the ''**NbtCompound**''.+This function does the opposite of ''**writeNbt**''. It takes in an ''**NbtCompound**'' (the same one we wrote in ''**writeNbt**'') and a ''**RegistryWrapper.WrapperLookup**'', creates a brand ''**new StateSaverAndLoader**'' and stuffs it with the data inside the ''**NbtCompound**''.
  
   * Note: how we pull out the int we stored earlier with ''**getInt**'' and how the string we pass in is the same one we used in ''**writeNbt**''.   * Note: how we pull out the int we stored earlier with ''**getInt**'' and how the string we pass in is the same one we used in ''**writeNbt**''.
  
-Now we just need to add one more utility function which hooks everything up together. This function will take a ''**MinecraftServer**'' and from it, get the ''**PersistentStateManager**''. ''**PersistentStateManager**'' has a function ''**getOrCreate**'' which will use our ''**MOD_ID**'' as a key to see if it has an instance of our ''**StateSaverAndLoader**'' or if it needs to create one. If it needs to create one, it'll call the function we just wrote ''**createFromNbt**'' passing in the previously saved-to-disk ''**NbtCompound**''. Ultimately the function returns the ''**StateSaverAndLoader**'' for the given ''**MinecraftServer**''.+Now we just need to add one more utility function which hooks everything up together. This function will take a ''**MinecraftServer**'' and from it, get the ''**PersistentStateManager**''. ''**PersistentStateManager**'' has a function ''**getOrCreate**'' which will use our ''**MOD_ID**'' as a key to see if it has an instance of our ''**StateSaverAndLoader**'' or if it needs to create one. If it needs to create one, it'll call the function we just wrote ''**createFromNbt**'' passing in the previously saved-to-disk ''**NbtCompound**'' and a ''**RegistryWrapper.WrapperLookup**''. Ultimately the function returns the ''**StateSaverAndLoader**'' for the given ''**MinecraftServer**''.
  
 <code java> <code java>
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     // ... (Previously written code)     // ... (Previously written code)
 +
 +    private static Type<StateSaverAndLoader> type = new Type<>(
 +            StateSaverAndLoader::new, // If there's no 'StateSaverAndLoader' yet create one
 +            StateSaverAndLoader::createFromNbt, // If there is a 'StateSaverAndLoader' NBT, parse it with 'createFromNbt'
 +            null // Supposed to be an 'DataFixTypes' enum, but we can just pass null
 +    );
  
     public static StateSaverAndLoader getServerState(MinecraftServer server) {     public static StateSaverAndLoader getServerState(MinecraftServer server) {
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         // stores it inside the 'PersistentStateManager'. The subsequent calls to 'getOrCreate' pass in the saved         // stores it inside the 'PersistentStateManager'. The subsequent calls to 'getOrCreate' pass in the saved
         // 'StateSaverAndLoader' NBT on disk to our function 'StateSaverAndLoader::createFromNbt'.         // 'StateSaverAndLoader' NBT on disk to our function 'StateSaverAndLoader::createFromNbt'.
-        // +        StateSaverAndLoader state = persistentStateManager.getOrCreate(type, ExampleMod.MOD_ID);
-        // (Note: 'DataFixTypes.LEVEL' is used as it's a required parameter but the decision to use 'DataFixTypes.LEVEL' specifically is arbitrary.) +
-        StateSaverAndLoader state = persistentStateManager.getOrCreate( +
-                new Type<>(StateSaverAndLoader::new, StateSaverAndLoader::createFromNbt, DataFixTypes.LEVEL), +
-                ExampleMod.MOD_ID);+
  
         // If state is not marked dirty, when Minecraft closes, 'writeNbt' won't be called and therefore nothing will be saved.         // If state is not marked dirty, when Minecraft closes, 'writeNbt' won't be called and therefore nothing will be saved.
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 import net.minecraft.world.PersistentStateManager; import net.minecraft.world.PersistentStateManager;
 import net.minecraft.world.World; import net.minecraft.world.World;
-import net.minecraft.datafixer.DataFixTypes; 
  
 public class StateSaverAndLoader extends PersistentState { public class StateSaverAndLoader extends PersistentState {
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     }     }
  
-    public static StateSaverAndLoader createFromNbt(NbtCompound tag) {+    public static StateSaverAndLoader createFromNbt(NbtCompound tag, RegistryWrapper.WrapperLookup registryLookup) {
         StateSaverAndLoader state = new StateSaverAndLoader();         StateSaverAndLoader state = new StateSaverAndLoader();
         state.totalDirtBlocksBroken = tag.getInt("totalDirtBlocksBroken");         state.totalDirtBlocksBroken = tag.getInt("totalDirtBlocksBroken");
         return state;         return state;
     }     }
 +
 +    private static Type<StateSaverAndLoader> type = new Type<>(
 +            StateSaverAndLoader::new, // If there's no 'StateSaverAndLoader' yet create one
 +            StateSaverAndLoader::createFromNbt, // If there is a 'StateSaverAndLoader' NBT, parse it with 'createFromNbt'
 +            null // Supposed to be an 'DataFixTypes' enum, but we can just pass null
 +    );
  
     public static StateSaverAndLoader getServerState(MinecraftServer server) {     public static StateSaverAndLoader getServerState(MinecraftServer server) {
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         // stores it inside the 'PersistentStateManager'. The subsequent calls to 'getOrCreate' pass in the saved         // stores it inside the 'PersistentStateManager'. The subsequent calls to 'getOrCreate' pass in the saved
         // 'StateSaverAndLoader' NBT on disk to our function 'StateSaverAndLoader::createFromNbt'.         // 'StateSaverAndLoader' NBT on disk to our function 'StateSaverAndLoader::createFromNbt'.
-        // +        StateSaverAndLoader state = persistentStateManager.getOrCreate(type, ExampleMod.MOD_ID);
-        // (Note: 'DataFixTypes.LEVEL' is used as it's a required parameter but the decision to use 'DataFixTypes.LEVEL' specifically is arbitrary.) +
-        StateSaverAndLoader state = persistentStateManager.getOrCreate( +
-                new Type<>(StateSaverAndLoader::new, StateSaverAndLoader::createFromNbt, DataFixTypes.LEVEL), +
-                ExampleMod.MOD_ID);+
  
         // If state is not marked dirty, when Minecraft closes, 'writeNbt' won't be called and therefore nothing will be saved.         // If state is not marked dirty, when Minecraft closes, 'writeNbt' won't be called and therefore nothing will be saved.
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     }     }
  
-    public static StateSaverAndLoader createFromNbt(NbtCompound tag) {+    public static StateSaverAndLoader createFromNbt(NbtCompound tag, RegistryWrapper.WrapperLookup registryLookup) {
         StateSaverAndLoader state = new StateSaverAndLoader();         StateSaverAndLoader state = new StateSaverAndLoader();
         state.totalDirtBlocksBroken = tag.getInt("totalDirtBlocksBroken");         state.totalDirtBlocksBroken = tag.getInt("totalDirtBlocksBroken");
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 import net.minecraft.world.PersistentStateManager; import net.minecraft.world.PersistentStateManager;
 import net.minecraft.world.World; import net.minecraft.world.World;
-import net.minecraft.datafixer.DataFixTypes; 
  
 import java.util.HashMap; import java.util.HashMap;
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     }     }
  
-    public static StateSaverAndLoader createFromNbt(NbtCompound tag) {+    public static StateSaverAndLoader createFromNbt(NbtCompound tag, RegistryWrapper.WrapperLookup registryLookup) {
         StateSaverAndLoader state = new StateSaverAndLoader();         StateSaverAndLoader state = new StateSaverAndLoader();
         state.totalDirtBlocksBroken = tag.getInt("totalDirtBlocksBroken");         state.totalDirtBlocksBroken = tag.getInt("totalDirtBlocksBroken");
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         return state;         return state;
     }     }
 +
 +    private static Type<StateSaverAndLoader> type = new Type<>(
 +            StateSaverAndLoader::new, // If there's no 'StateSaverAndLoader' yet create one
 +            StateSaverAndLoader::createFromNbt, // If there is a 'StateSaverAndLoader' NBT, parse it with 'createFromNbt'
 +            null // Supposed to be an 'DataFixTypes' enum, but we can just pass null
 +    );
  
     public static StateSaverAndLoader getServerState(MinecraftServer server) {     public static StateSaverAndLoader getServerState(MinecraftServer server) {
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         // stores it inside the 'PersistentStateManager'. The subsequent calls to 'getOrCreate' pass in the saved         // stores it inside the 'PersistentStateManager'. The subsequent calls to 'getOrCreate' pass in the saved
         // 'StateSaverAndLoader' NBT on disk to our function 'StateSaverAndLoader::createFromNbt'.         // 'StateSaverAndLoader' NBT on disk to our function 'StateSaverAndLoader::createFromNbt'.
-        // +        StateSaverAndLoader state = persistentStateManager.getOrCreate(type, ExampleMod.MOD_ID);
-        // (Note: 'DataFixTypes.LEVEL' is used as it's a required parameter but the decision to use 'DataFixTypes.LEVEL' specifically is arbitrary.) +
-        StateSaverAndLoader state = persistentStateManager.getOrCreate( +
-                new Type<>(StateSaverAndLoader::new, StateSaverAndLoader::createFromNbt, DataFixTypes.LEVEL), +
-                ExampleMod.MOD_ID);+
  
         // If state is not marked dirty, when Minecraft closes, 'writeNbt' won't be called and therefore nothing will be saved.         // If state is not marked dirty, when Minecraft closes, 'writeNbt' won't be called and therefore nothing will be saved.
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 Running the client now, all our player-specific data is correctly saved. Running the client now, all our player-specific data is correctly saved.
  
-  * Note: each time you restart the minecraft client with fabric, you're assigned a new UUID, so it may seem like it's not working, but that's just because of the developer environment. (If you run the fabric multiplayer server, 'Minecraft Server' and use authme, you could verify it does indeed work as it's supposed to.)+==== Important Caveat ==== 
 + 
 +  * Each time you restart the minecraft client with fabric, you're assigned a new random UUID each launch, so it may seem like our code is not working because it's pulling data for a new UUID never before seen. If you want to verify everything is working correctly, download [[https://www.curseforge.com/minecraft/mc-mods/auth-me|AuthMe]] and drop the ''AuthMe.jar'' into run/mods. Login to your Minecraft account from the multiplayer screen. This will now change the random UUID to your actual UUID and therefore you can test if the data is correctly saved and associated with one UUID even across restarts. (You don't have to keep doing this, once you've verified once that, if the UUID is the same across launches, the data is correctly saved, you can just develop the mod normally safe in the knowledge that your data will be saved)
  
 Just remember if you add new fields to ''**PlayerData**'' or ''**StateSaveAndLoader**'' you need to correctly do the work of writing and loading those fields in the ''**writeNbt**'' and ''**createFromNbt**'' functions //always//. If you forget this step, your data won't be properly saved or loaded from disk. Just remember if you add new fields to ''**PlayerData**'' or ''**StateSaveAndLoader**'' you need to correctly do the work of writing and loading those fields in the ''**writeNbt**'' and ''**createFromNbt**'' functions //always//. If you forget this step, your data won't be properly saved or loaded from disk.
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   * Note: The ''**playerData**'' we created isn't the up-to-date one that lives on the server. We simply create our own copy of ''**PlayerData**'' client-side and update it as we receive packets. Since it's ''**public static**'' that means you can access it from anywhere on the client.   * Note: The ''**playerData**'' we created isn't the up-to-date one that lives on the server. We simply create our own copy of ''**PlayerData**'' client-side and update it as we receive packets. Since it's ''**public static**'' that means you can access it from anywhere on the client.
  
-  * Note: each time you restart the minecraft client with fabric, you're assigned a new UUID, so it may seem like it's not working, but that's just because of the developer environment. (If you run the fabric multiplayer server, 'Minecraft Server' and use authme, you could verify it does indeed work as it's supposed to.)+==== Important Caveat ==== 
 + 
 +  * Each time you restart the minecraft client with fabric, you're assigned a new random UUID each launch, so it may seem like our code is not working because it's pulling data for a new UUID never before seen. If you want to verify everything is working correctly, download [[https://www.curseforge.com/minecraft/mc-mods/auth-me|AuthMe]] and drop the ''AuthMe.jar'' into run/mods. Login to your Minecraft account from the multiplayer screen. This will now change the random UUID to your actual UUID and therefore you can test if the data is correctly saved and associated with one UUID even across restarts. (You don't have to keep doing this, once you've verified once that, if the UUID is the same across launches, the data is correctly saved, you can just develop the mod normally safe in the knowledge that your data will be saved)
  
 ====== More Involved Player Data ====== ====== More Involved Player Data ======
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 import net.minecraft.world.PersistentStateManager; import net.minecraft.world.PersistentStateManager;
 import net.minecraft.world.World; import net.minecraft.world.World;
-import net.minecraft.datafixer.DataFixTypes; 
  
 import java.util.HashMap; import java.util.HashMap;
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     }     }
  
-    public static StateSaverAndLoader createFromNbt(NbtCompound tag) {+    public static StateSaverAndLoader createFromNbt(NbtCompound tag, RegistryWrapper.WrapperLookup registryLookup) {
         StateSaverAndLoader state = new StateSaverAndLoader();         StateSaverAndLoader state = new StateSaverAndLoader();
         state.totalDirtBlocksBroken = tag.getInt("totalDirtBlocksBroken");         state.totalDirtBlocksBroken = tag.getInt("totalDirtBlocksBroken");
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         return state;         return state;
     }     }
 +
 +    private static Type<StateSaverAndLoader> type = new Type<>(
 +            StateSaverAndLoader::new, // If there's no 'StateSaverAndLoader' yet create one
 +            StateSaverAndLoader::createFromNbt, // If there is a 'StateSaverAndLoader' NBT, parse it with 'createFromNbt'
 +            null // Supposed to be an 'DataFixTypes' enum, but we can just pass null
 +    );
  
     public static StateSaverAndLoader getServerState(MinecraftServer server) {     public static StateSaverAndLoader getServerState(MinecraftServer server) {
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         // stores it inside the 'PersistentStateManager'. The subsequent calls to 'getOrCreate' pass in the saved         // stores it inside the 'PersistentStateManager'. The subsequent calls to 'getOrCreate' pass in the saved
         // 'StateSaverAndLoader' NBT on disk to our function 'StateSaverAndLoader::createFromNbt'.         // 'StateSaverAndLoader' NBT on disk to our function 'StateSaverAndLoader::createFromNbt'.
-        // +        StateSaverAndLoader state = persistentStateManager.getOrCreate(type, ExampleMod.MOD_ID);
-        // (Note: 'DataFixTypes.LEVEL' is used as it's a required parameter but the decision to use 'DataFixTypes.LEVEL' specifically is arbitrary.) +
-        StateSaverAndLoader state = persistentStateManager.getOrCreate( +
-                new Type<>(StateSaverAndLoader::new, StateSaverAndLoader::createFromNbt, DataFixTypes.LEVEL), +
-                ExampleMod.MOD_ID);+
  
         // If state is not marked dirty, when Minecraft closes, 'writeNbt' won't be called and therefore nothing will be saved.         // If state is not marked dirty, when Minecraft closes, 'writeNbt' won't be called and therefore nothing will be saved.
tutorial/persistent_states.1695879458.txt.gz · Last modified: 2023/09/28 05:37 by jmanc3