Custom @Context

You can create custom context providers for objects like User, Account, Member, Guild, or Party, eliminating the need to first retrieve data from the Player object and then use a service or manager.

Boring theory

To do this, implement the ContextProvider<SENDER, T> interface and register it.

• SENDER is a platform-specific sender type. (see What is SENDER?)
• T is the context type you want to provide.

Practical example with Account

Imagine you have an Account class with player data like balance, level, and experience. With a context provider you can access the Account directly in command methods.

In this example:

SENDER is platform-specific sender type CommandSender
T is the context type Account

// AccountContextProvider.java
public class AccountContextProvider implements ContextProvider<CommandSender, Account> {

    private final AccountManager accountManager;

    public AccountContext(AccountManager accountManager) {
        this.accountManager = accountManager;
    }

    @Override
    public ContextResult<Account> provide(Invocation<CommandSender> invocation) {
        if (!(invocation.sender() instanceof Player player)) {
            return ContextResult.error("&cOnly players can use this command!");
        }
        
        return ContextResult.ok(() -> {
            Account account = this.accountManager.getAccount(player.getName());
            if (account == null) {
                throw new IllegalStateException("&cAccount " + player.getName() + " not found");
            }

            return account;
        });
    }
}

Now we can create a BalanceCommand that access the sender's Account:

// BalanceCommand.java
@Command(name = "balance")
public class BalanceCommand {
    @Execute
    void balance(
            @Context CommandSender sender,
            @Context Account account
    ) {
        double balance = account.getBalance();
        sender.sendMessage("Your current balance is: " + balance);
    }
}

And finally, we can register the custom context provider in the LiteCommands builder:

.commands(
    new AccountCommand()
)
.context(Account.class, new AccountContextProvider(accountManager))
.build();

Run the command /balance

Input

/balance

Output

Your current balance is: 100.0

This example shows how custom context providers in LiteCommands simplify command logic and improve code readability by providing direct access to relevant objects.

Check out real examples!

This code is a simplified version of the code from the EternalEconomy Plugin.
See the full code of the EternalEconomy Plugin on GitHub.

Martin Sulikowski Norbert Dejlich

Last edited about 2 months ago

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fdf64fc-GH-28 Refactor docs. (#28)