Interface PermissionFunction

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface PermissionFunction

Functional interface for checking permissions.

This is the core hook point for permission plugins like LuckPerms. A permission function takes a permission string and returns a Tristate indicating whether the permission is granted, denied, or undefined.

Example implementation:

PermissionFunction func = permission -> {
    if (permission.startsWith("admin.")) {
        return Tristate.FALSE; // Deny all admin permissions
    }
    return Tristate.UNDEFINED; // Defer to default
};

See Also:

• PermissionProvider
• PermissionSubject

Field Summary

Fields

Modifier and Type	Field	Description
static final PermissionFunction	ALWAYS_FALSE	A permission function that always returns Tristate.FALSE.
static final PermissionFunction	ALWAYS_TRUE	A permission function that always returns Tristate.TRUE.
static final PermissionFunction	ALWAYS_UNDEFINED	A permission function that always returns Tristate.UNDEFINED.

Method Summary

Modifier and Type	Method	Description
Tristate	getPermissionValue(String permission)	Gets the permission value for the given permission string.
default PermissionFunction	withFallback(PermissionFunction other)	Creates a new permission function that checks this function first, and falls back to the other function if this returns Tristate.UNDEFINED.

Field Details

ALWAYS_UNDEFINED

static final PermissionFunction ALWAYS_UNDEFINED

A permission function that always returns Tristate.UNDEFINED.

ALWAYS_TRUE

static final PermissionFunction ALWAYS_TRUE

A permission function that always returns Tristate.TRUE. Useful for console or admin bypass.

ALWAYS_FALSE

static final PermissionFunction ALWAYS_FALSE

A permission function that always returns Tristate.FALSE.

Method Details

getPermissionValue

@Nonnull
Tristate getPermissionValue(@Nonnull
 String permission)

Gets the permission value for the given permission string.

Parameters:

permission - the permission to check (e.g., "numdrassl.command.server")

Returns:

the tristate permission value

withFallback

@Nonnull
default PermissionFunction withFallback(@Nonnull
 PermissionFunction other)

Creates a new permission function that checks this function first, and falls back to the other function if this returns Tristate.UNDEFINED.

Parameters:

other - the fallback function

Returns:

a combined permission function