Common Pitfalls

While we try to make the API a pleasure to use, there are the occasional rough edges, and you should be aware of them.

Accessing the API at construction time

In Velocity, plugin loading is split into two steps: construction and initialization. The code in your plugin's constructor is part of the construction phase. There is very little you can do safely during construction, especially as the API does not specify which operations are safe to run during construction. Notably, you can't register an event listener in your constructor, because you need to have a valid plugin registration, but Velocity can't register the plugin until the plugin has been constructed.

To break this cycle, you should always wait for initialization, which is indicated when Velocity fires the ProxyInitializeEvent. We can do things on initialization by adding a listener for this event, as shown below. Note that Velocity automatically registers your plugin main class as a listener.

@Subscribe
public void onProxyInitialization(ProxyInitializeEvent event) {
    // Do some operation demanding access to the Velocity API here.
    // For instance, we could register an event:
    server.getEventManager().register(this, new PluginListener());
}

Audience operations are not fully supported

Operation	Supported
Chat messages	Yes
Action bar messages	Yes
Titles	Yes
Bossbars	Yes
Tablist header and footer	Yes
Resource packs	Yes
Sound	No
Book	No