Command Library

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The Command Library is a simple system for creating commands and registering them with parent commands or the server. The intention of this system is to provide the missing Command class that Sponge lacks for structuring commands, storing CommandSpecs, and managing instances. Both an annotation framework and settings (builder-like) system can be used.

This library was added in PR #1 by Simon_Flash.

Command

The Command [link] class is an abstract class implementing CommandExecutor that represents a single command. This class stores the command’s CommandSpec, children, aliases, permission, description, and usage (whew!).

An implementing class should extend Command and provide a constructor accepting a Command.Settings, which will contain any settings defined through annotations. The constructor must be public or (ideally) annotated with @Inject. Examples with both the annotation framework and settings system are shown below (the reader is left to implement Command#execute as they see fit. s

@Singleton
@Aliases({"one", "two"})
@Permission("permission.node")
public class ExampleCommand extends Command {

    @Inject
    private ExampleCommand(Settings settings) {
        super(settings);
    }

}

@Singleton
public class ExampleCommand extends Command {

    @Inject
    private ExampleCommand(Settings settings) {
        super(settings.aliases("one", "two").permission("permission.node"));
    }

}

In addition to a command’s aliases and permission node, it’s description and children may also be defined using either system. However, because annotations only support compile-time values, it is not possible to define higher-level features like arguments in them. Instead, the Settings#arguments method must be used to define any arguments the command has.

CommandService

The piece that connects these commands together is the CommandService [link], which stores command instances and is necessary for structuring child commands. To register our command above, create a CommandService with your PluginContainer and register the ExampleCommand.class command. The service is responsible for instantiating any child commands necessary.

PluginContainer container;
CommandService commands = CommandService.of(container);

commands.register(ExampleCommand.class);