BotCommands/io.github.freya022.botcommands.api.commands.application/ApplicationCommandFilter

ApplicationCommandFilter

@InterfacedService(acceptMultiple = true)

interface ApplicationCommandFilter : Filter(source)

Prevents application command execution by returning an error object to the command executor, before which you must acknowledge the interaction.

Filters run when an application command is about to be executed, i.e., after the permissions/rate limits... were checked.

Combining filters

Filters can be combined with and/or (static methods for Java users).

Requirements

Register your instance as a service with @BService. This is not required if you pass the instance directly to the command builder.
Implement either check (Java) or checkSuspend (Kotlin).
(Optional) Set your filter as a command-specific filter by disabling global.

Execution order

The execution order of global filters is determined by the priority of the service, while command-specific filters use the insertion order.

Example - Accepting commands only in a single channel

Note: For the example's sake, I will reply directly on each failed condition, however, I recommend having a separate function/class to handle rejections, as to not duplicate code on each rejection case.

@BService
class MyApplicationCommandFilter : ApplicationCommandFilter {

    override val global: Boolean get() = true

    override suspend fun checkSuspend(
        event: GenericCommandInteractionEvent,
        commandInfo: ApplicationCommandInfo
    ): String? {
        if (event.channel!!.idLong != 722891685755093076) {
            event.reply_("Can only run commands in <#722891685755093076>", ephemeral = true).await()
            return "Wrong channel"
        }
        return null
    }
}

@BService
public class MyApplicationCommandFilter implements ApplicationCommandFilter {

    @Override
    public boolean getGlobal() {
        return true;
    }

    @Nullable
    @Override
    public String check(@NotNull GenericCommandInteractionEvent event, @NotNull ApplicationCommandInfo commandInfo) {
        if (event.getChannel().getIdLong() != 722891685755093076L) {
            event.reply("Can only run commands in <#722891685755093076>").setEphemeral(true).queue();
            return "Not the right channel";
        }
        return null;
    }
}