Differences

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--- tutorial:blockentity_sync_itemstack [2024/08/26 02:27] – [Reading saved data from ItemStack] solidblock
+++ tutorial:blockentity_sync_itemstack [2024/08/27 02:37] (current) – [Block drops with data] solidblock
@@ Line 5: / Line 5: @@
 When you create a block with block entity, you might want to place the block with predefined NBT data from an ''ItemStack'' (of your ''BlockItem''), or save the ''BlockEntity'' data in the ''ItemStack'' after breaking the block.
-In this tutorial, we assume you have created a [[block]] (and block item) and the [[blockentity|block entity]], and [[blockentity_modifying_data|stored data for it]].
+In this tutorial, we assume you have created a [[blocks|block]] (and block item) and the [[blockentity|block entity]], and [[blockentity_modify_data|stored data for it]].
-===== Block Drops with data =====
+===== Block drops with data =====
-For a block to drop an ''ItemStack'' with the **Nbt** from the ''BlockEntity'' of the broken block, we only need to change the //loot table//.
+For a block to drop an ''ItemStack'' with the NBT or data components from the ''BlockEntity'' of the broken block, we only need to change the //loot table//.
 ==== For versions since 1.20.5 ====
@@ Line 129: / Line 129: @@
 </code>
-===== Changing ItemStack's BlockEntity data=====
+Similarly, you can also modify the ''getName'' method so the data can be displayed directly in the name. In this case, you have to modify how your block item is registered to create ''DemoBlockItem'' instead of ''BlockItem''.
+<code java DemoBlockItem.class>
+public class DemoBlockItem extends BlockItem {
+  public DemoBlockItem(Block block, Settings settings) {
+    super(block, settings);
+  }
-We can change our tooltip to always display some default value even if the stack does not have any BlockEntity data.
+  @Override
+  public Text getName(ItemStack stack) {
+    final MutableText name = Text.translatable(stack.getTranslationKey());
+    if (stack.contains(TutorialDataComponentTypes.NUMBER)) {
+      name.append(" - number=" + stack.get(TutorialDataComponentTypes.NUMBER));
+    }
+    return name;
+  }
+}
+</code>
+===== Pick item with data =====
+In Creative Mode, when you pick item (by pressing the mouse wheel) while holding ''Ctrl'', you can get an item stack with all block entity data. However, if you don't press ''Ctrl'', you can only get one without data, unless you modify ''getPickStack'' method in the ''DemoBlock'' class:
 <code java>
-public class DemoBlock extends Block implements BlockEntityProvider {
+  @Override
+  public ItemStack getPickStack(WorldView world, BlockPos pos, BlockState state) {
-    [...]
+    final ItemStack pickStack = super.getPickStack(world, pos, state);
+    final BlockEntity blockEntity = world.getBlockEntity(pos);
-    @Override
+    if (blockEntity instanceof DemoBlockEntity demoBlockEntity) {
-    public void appendTooltip(ItemStack stack, BlockView world, List<Text> tooltip, TooltipContext context) {
+      pickStack.applyComponentsFrom(demoBlockEntity.createComponentMap());
-        NbtCompound nbt = BlockItem.getBlockEntityNbt(stack);
-        if (nbt == null){
-            NbtCompound nbt = new NbtCompound();
-            nbt.putInt("number", 0);
-            BlockItem.setBlockEntityNbt(stack, ExampleMod.DEMO_BLOCK_ENTITY, nbt);
-        }
-        tooltip.add(Text.literal("Number: "+nbt.getInt("number"))
     }
-}
+    return pickStack;
+  }
 </code>
-===== Placing Block with data =====
+> **Note:** When ''Ctrl'' is not pressed down, pick-stack happend only on client side. Therefore, you should modify ''toUpdatePacket'' and ''toInitialChunkDataNbt'', and call ''updateListeners'' when modifying data (see [[blockentity modify data#sync data from server to client]]).
-**Is automatic!** As long as the data is in the //"BlockEntityTag"// subNbt (e.g. by using the ''BlockItem.getBlockEntityNbt'' and ''BlockItem.setBlockEntityNbt'' helper methods) under tag keys recognized by the ''readNbt'' method of the ''BlockEntity''.
 ===== Helpful Reference =====
-If something still isn't clear or you want more examples, I highly recommend looking at the Minecraft implementation of ''ShulkerBoxBlock'' and ''ShulkerBoxBlockEntity''. That for example also implements ''Nameable'' interface and has code to **save custom names** through ''ItemStack'' and ''BlockEntity''.
+More examples can bee seen in vanilla codes, such as ''ShulkerBoxBlock'' and ''ShulkerBoxBlockEntity'', which implements ''Nameable'' interface and has code to **save custom names** through ''ItemStack'' and ''BlockEntity''. There are also other useful information:
-==== Loot Tables ====
-More info on Loot tables on [[https://minecraft.wiki/w/Loot_table|Minecraft Wiki]].
-Vanilla loot tables: .minecraft\versions\//[version]//\//[version]//.jar\data\minecraft\loot_tables\
-Also, this [[https://misode.github.io/loot-table/|Loot Table Generator]] might be useful.
+  * [[https://minecraft.wiki/w/Loot_table|Loot table page in Minecraft Wiki]]
+  * [[datagen_loot|Data generation of loot tables]]