====== Registry System ======

You will need to register most content you add to the game. This helps with:
  * Letting the game know your content exists
  * Verifying game content between client & server
  * Handling invalid content in a save
  * Preventing conflicts between different mods
  * Compression for client <-> server communication and data saving
  * Abstracting or hiding numerical IDs

When registering any type of content, you pass in an ''<yarn class_2960>'', which is a label for your addition. <yarn class_2960>s– often abbreviated as IDs– have a namespace and path. In most cases, the namespace is the ID of your mod, and the path is the name of the content you’re registering. For example, the standard dirt block has the ID of ''%%minecraft:dirt%%''.

Using custom content without registering it can lead to buggy behavior, such as missing textures, world save issues, and crashes. The game will usually let you know if you forget to register something.

===== Registry Types =====

When registering content, you need to specify which registry you are adding content to. The base game provides registries for all vanilla content, which can be found in ''%%Registries%%'' (for 1.19.3 and above) or ''Registry'' (for below 1.19.3). Two examples of registries you may use include ''Registries.ITEM'' (for 1.19.3 above)/''Registry.ITEM'' (for 1.19.2 below) for items and ''Registries.BLOCK'' (for 1.19.3 above)/''Registry.BLOCK'' (for 1.19.2 below) for blocks.

For a deeper overview and description of all available registries, read the [[tutorial:registry_types|registry types]] page.

===== Registering Content =====

Use ''<yarn class_2378>.<yarn method_10230>'' for adding content to registries:

<yarncode java>
public static <T> T method_10230(class_2378<? super T> registry, class_2960 id, T entry) {
    return ((class_2385)registry).method_10272(id, entry);
}
</yarncode>
**registry** - an instance of the registry you want to add content to. A list of all vanilla registries, located in ''<yarn class_2378>'', can be found in the [[tutorial:registry_types|registry types]] page.

**id** - an identifying label for your content inside the registry. Standard convention is ''%%modid:name%%'', as seen with ''%%minecraft:dirt%%''.

**entry** - an instance of the content you want to register.

===== Registry Methods =====

''<yarn method_10223>'' - returns the entry associated with an ID inside a registry. If the entry doesn’t exist, ''<yarn class_2348>'' returns the default registry value, and ''<yarn class_2370>'' returns null.

<yarncode java>
@Nullable
public abstract T method_10223(@Nullable class_2960 id);
</yarncode>

----

''<yarn method_10221>'' - returns the ''<yarn class_2960>'' associated with an entry inside a registry. If the entry doesn’t exist, ''<yarn class_2348>'' returns the default registry ID, and ''<yarn class_2370>'' returns null.

<yarncode java>
@Nullable
public abstract class_2960 method_10221(T entry);
</yarncode>

----

''<yarn method_10206>'' - returns the internal integer ID associated with an entry inside a registry. If the entry doesn’t exist, ''<yarn class_2348>'' returns the raw ID of the default registry value, and ''<yarn class_2370>'' returns -1.

<yarncode java>
public abstract int method_10206(@Nullable T entry);
</yarncode>