Gestore dei plugin

The Plugin Manager is what your plugin gets sent to after being loaded by the server at startup. The server loads your plugin by finding its main class, annotated by the Plugin annotation that holds its general information, and sends a new instance of it to the manager. The manager then keeps that instance in its own collection that you can look into and pull from using methods provided by itself, thus allowing you to easily interact with another loaded plugin if you so desire.

The PluginManager Class

Public methods inside the PluginManager are used to grab information about the current collection of loaded plugins, alongside their instances. The plugins are stored inside a PluginContainer (discussed in next section) to allow for an easy center of information about the specific plugin. As an example, you can use the PluginManager to communicate with another plugin, grabbing its instance and using the methods it offers to provide compatibility or extended features by means of your calling plugin.

Obtaining the Plugin Manager

You can get an instance of the server’s PluginManager using a few different ways.

1. Dependency Injection

Suggerimento

See the Iniezione di dipendenze guide for help on using dependency injection.

The PluginManager is one of the few API instances that are injected into the main class upon being loaded. To ask for a reference, create a new variable to hold the PluginManager instance and simply annotate it with @Inject.

import com.google.inject.Inject;
import org.spongepowered.api.plugin.PluginManager;

@Inject
private PluginManager pluginManager;

2. The Service Manager

Suggerimento

See Servizi for a full guide about the Service Manager.

The service manager also holds an instance of the server’s PluginManager. Simply use the method ServiceManager#provide(Class), passing the PluginManager“s class (PluginManager.class) as a parameter.

private PluginManager pluginManager = serviceManager.provideUnchecked(PluginManager.class);

3. The Game Instance

Suggerimento

See the JavaDocs for Game for full information about the class, as well as its methods and their usage.

A game instance can provide a reference to the server’s PluginManager as well for convenience.

private PluginManager pluginManager = game.getPluginManager();

Now that you have an instance to the plugin manager, let’s use it.

4. Using the Sponge Class

The Sponge class works similarly to Game, with the exception that since Sponge contains static methods. It can be accessed anywhere throughout your plugin. You also do not need to store an instance of it, as you would need to do with Game.

import org.spongepowered.api.Sponge;

private PluginManager pluginManager = Sponge.getPluginManager();

Using the Plugin Manager

The plugin manager provides several methods for working with plugins.

A lot of methods return plugin containers, which will be discussed in the next section. Plugin containers are pretty much self-explanatory «containers» of the actual plugin instance.

With the plugin manager, it is possible to get all plugins currently loaded through the plugin manager:

import org.spongepowered.api.plugin.PluginContainer;

import java.util.Collection;

private Collection<PluginContainer> plugins = pluginManager.getPlugins();

Or, it is possible to obtain an instance to a plugin container directly, by the example shown below:

private PluginContainer myOtherPlugin = pluginManager.getPlugin("myOtherPluginId").orElse(null);

The PluginContainer Class

When grabbing a plugin from the PluginManager, you’ll notice very quickly that you are not given an immediate instance of the requested plugin. Instead, you’ll be greeted by a PluginContainer containing information about the plugin attained from its @Plugin annotation in its main class, as well as the loaded instance.

The PluginContainer will hold any generic information about the plugin set by its owning developer. You can use information from here instead of hard-coding what you know about it in your supporting plugin. An example scenario would be if the owning developer changes the name of the plugin, references to the latter in the supporting plugin would not become wrong as a result of this change, provided you’ve used the method PluginContainer#getName() to get its name.

private PluginContainer myOtherPlugin = pluginManager.getPlugin("myOtherPluginId").orElse(null);
private MyOtherPlugin pluginInstance = (MyOtherPlugin) myOtherPlugin.getInstance().orElse(null);

Nota

PluginContainer#getInstance() will return as an Object. You need to cast it as the target plugin after obtaining it from the container.