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add improved section about existing buses
Additionally, mods may create their own events and fire them for other mods to listen for, allowing for higher compatibility.
Additionally, mods may create their own events and fire them for other mods to listen for, allowing for higher compatibility.
= Cancellable Events =
== Cancellable Events ==
An event may be marked as '''cancellable''', which allows event listeners to cancel the event.
An event may be marked as '''cancellable''', which allows event listeners to cancel the event.
To mark an event as cancellable, the event class should be annotated with <code>@Cancelable</code>. This will automatically make <code>Event#isCancelable()</code> return <code>true</code>. Modders may check if an event has a result through the presence of the annotation or by calling the given method.
To mark an event as cancellable, the event class should be annotated with <code>@Cancelable</code>. This will automatically make <code>Event#isCancelable()</code> return <code>true</code>. Modders may check if an event has a result through the presence of the annotation or by calling the given method.
= Events with Results =
== Events with Results ==
An event may have a ```result''', which is an enum of <code>Event.Result</code>.
An event may have a '''result''', which is an enum of <code>Event.Result</code>.
The <code>Event.Result</code> enum has three values: <code>ALLOW</code>, <code>DEFAULT</code>, and <code>DENY</code>. The meaning of these result values is entirely dependent on the event itself.
The <code>Event.Result</code> enum has three values: <code>ALLOW</code>, <code>DEFAULT</code>, and <code>DENY</code>. The meaning of these result values is entirely dependent on the event itself.
To mark an event as having a result, the event class should be annotated with <code>@Event.HasResult</code>. This will automatically make <code>Event#hasResult</code> return <code>true</code>. Modders may check if an event has a result through the presence of the annotation or by calling the given method.
To mark an event as having a result, the event class should be annotated with <code>@Event.HasResult</code>. This will automatically make <code>Event#hasResult</code> return <code>true</code>. Modders may check if an event has a result through the presence of the annotation or by calling the given method.
= Event Bus =
== Event Bus ==
An '''event bus''' is an object which holds a list of event listeners, and the logic for firing the events. Events may be posted on these event buses, which then invokes the handlers.
An '''event bus''' is an object which holds a list of event listeners, and the logic for firing the events. Events may be posted on these event buses, which then invokes the handlers.
=== Existing Buses ===
Forge exposes three main families of event buses: the main Forge event bus, the mod-specific event buses, and the network channel event buses.
The '''main Forge event bus''' is located at <code>MinecraftForge#EVENT_BUS</code>, and is where most events relating to ingame actions or events are fired on, such as events for ticking, block interactions, and entity interactions.
<div class="mw-collapsible mw-collapsed" style="border: 2px solid; border-radius: 2px; padding: 5px; margin: 1em; overflow:auto;">
<div style="font-weight:bold; line-height:1.6;">List of events fired on the main Forge event bus</div>
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{{:Events/Forge bus}}
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The '''mod-specific event buses''' are the family of event buses where mod-related initialization and registration events are fired, such as the events for [[Registration|registering objects]] or setup on different physical sides. Only events which implement <code>IModBusEvent</code> may be fired or listened for on these event buses.
Each loaded mod has their own instance of a mod-specific event bus. The mod-specific event bus for the currently loading mod can be retrieved from <code>FMLModContainer#getEventBus()</code>, which is also accessible from <code>FMLJavaModLoadingContext#getModEventBus()</code>.
{{Tip|title=Tip|The mod-specific event buses are provided by the <code>javafml</code> language provider which is builtin to Forge Mod Loader. Custom language providers may provide other ways for mods to receive the different mod-related initialization and registration events; see the documentation of your custom language provider for details.}}
The '''network channel event buses''' are the family of event buses where different network-related events are fired. Each registered [[Networking|networking channel]] has their own instance of an event-bus in <code>NetworkInstance</code>, where only events pertinent to that channel are fired on.
The network channel event buses cannot be accessed directly; <code>EventNetworkChannel</code> provides methods to register events listeners to the event bus.
== Forge and Mod Buses ==
== Forge and Mod Buses ==