Package org.spongepowered.api.data

Interface Key<V extends Value<?>>

Type Parameters:

V - The type of Value

All Superinterfaces:

Keyed, ResourceKeyed

@CatalogedBy(Keys.class)
public interface Key<V extends Value<?>>
extends ResourceKeyed

Represents a key to an underlying Value such that the underlying value can be retrieved from a ValueContainer. For the key to be used through retrieval of DataHolders, it's required to use a DataRegistration if the data is needed to be serialized, or dynamically provided for through external mechanisms, through DataProviders.

If dynamic or persistent retention of the Values by keys is not desired, a registration with DataRegistration is optional. This would mean that any submitted Values of a Key without an associated DataRegistration will be only stored on a mutable DataHolder for the duration that that holder exists. The value would not persist between reloads, restarts, etc.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static interface	Key.Builder<E,V extends Value<E>>

Method Summary

Modifier and Type	Method	Description
static Key.Builder<?,?>	builder()	Creates a Key.Builder which allows creation of a Key to later be registered for accessing values from a ValueContainer.
Comparator<?>	elementComparator()	Gets the Comparator to compare values of this key.
BiPredicate<?,?>	elementIncludesTester()	Gets the includes tester BiPredicate.
Type	elementType()	Gets the type of the element of the Value this Key is representing.
static <E> Key<Value<E>>	from(ResourceKey resourceKey, Class<E> type)
static <V> Key<Value<V>>	from(org.spongepowered.plugin.PluginContainer plugin, String value, Class<V> type)
static <E> Key<ListValue<E>>	fromList(ResourceKey resourceKey, Class<E> type)
static <V> Key<ListValue<V>>	fromList(org.spongepowered.plugin.PluginContainer plugin, String value, Class<V> type)
static <K,V> Key<MapValue<K,V>>	fromMap(ResourceKey resourceKey, Class<K> keyType, Class<V> valueType)
static <K,V> Key<MapValue<K,V>>	fromMap(org.spongepowered.plugin.PluginContainer plugin, String value, Class<K> keyType, Class<V> valueType)
static <E> Key<SetValue<E>>	fromSet(ResourceKey resourceKey, Class<E> type)
static <V> Key<SetValue<V>>	fromSet(org.spongepowered.plugin.PluginContainer plugin, String value, Class<V> type)
<E extends DataHolder> void	registerEvent(org.spongepowered.plugin.PluginContainer plugin, Class<E> holderFilter, EventListener<ChangeDataHolderEvent.ValueChange> listener)	Register an event listener which listens to the value the key accesses changing.
Type	valueType()	Gets the type of the Value this Key is representing.

Methods inherited from interface org.spongepowered.api.ResourceKeyed

key

Method Detail

builder

static Key.Builder<?,?> builder()

Creates a Key.Builder which allows creation of a Key to later be registered for accessing values from a ValueContainer. It is the default policy that a custom created Key is NOT PERSISTENT by Sponge. If custom keys for DataHolders is desired to be persisted, a DataRegistration is required.

Returns:

The key builder

See Also:

DataRegistration

from

static <V> Key<Value<V>> from(org.spongepowered.plugin.PluginContainer plugin,
                              String value,
                              Class<V> type)

from

static <E> Key<Value<E>> from(ResourceKey resourceKey,
                              Class<E> type)

fromList

static <V> Key<ListValue<V>> fromList(org.spongepowered.plugin.PluginContainer plugin,
                                      String value,
                                      Class<V> type)

fromList

static <E> Key<ListValue<E>> fromList(ResourceKey resourceKey,
                                      Class<E> type)

fromSet

static <V> Key<SetValue<V>> fromSet(org.spongepowered.plugin.PluginContainer plugin,
                                    String value,
                                    Class<V> type)

fromSet

static <E> Key<SetValue<E>> fromSet(ResourceKey resourceKey,
                                    Class<E> type)

fromMap

static <K,V> Key<MapValue<K,V>> fromMap(org.spongepowered.plugin.PluginContainer plugin,
                                                    String value,
                                                    Class<K> keyType,
                                                    Class<V> valueType)

fromMap

static <K,V> Key<MapValue<K,V>> fromMap(ResourceKey resourceKey,
                                                    Class<K> keyType,
                                                    Class<V> valueType)

valueType

Type valueType()

Gets the type of the Value this Key is representing.

Returns:

The value generic type

elementType

Type elementType()

Gets the type of the element of the Value this Key is representing. On occasion, if the element is a Collection type, one can use ParameterizedType.getActualTypeArguments() to access type parameters, such as the element type parameter for List or Map values.

Returns:

The element generic type

elementComparator

Comparator<?> elementComparator()

Gets the Comparator to compare values of this key.

Returns:

The value comparator

elementIncludesTester

BiPredicate<?,?> elementIncludesTester()

Gets the includes tester BiPredicate. This predicate should return true when the second parameter (the key value) is included in the first one (the matcher value).

The default tester will always return false.

Returns:

The includes tester bi predicate

See Also:

KeyValueMatcher.Operator.INCLUDES, KeyValueMatcher.Operator.EXCLUDES

registerEvent

<E extends DataHolder> void registerEvent(org.spongepowered.plugin.PluginContainer plugin,
                                          Class<E> holderFilter,
                                          EventListener<ChangeDataHolderEvent.ValueChange> listener)

Register an event listener which listens to the value the key accesses changing.

Type Parameters:

E - The class type of the data holder

Parameters:

holderFilter - The data holder to filter with

listener - The event listener