ExpandoWithFinalizer<K extends Object, V extends Object> class

A weak key → strong value association similar to Expando, but with a finalization callback.

When a key becomes unreachable and is garbage-collected, the provided onFinalize (FinalizerCallback) is invoked with the last associated value.

The value remains alive while associated with the key. Replacing or removing the value cancels the pending finalization for the previous association.

Typical use cases:

  • Cleaning native resources tied to Dart objects
  • Cache entries that must release external handles
  • Lifecycle hooks without modifying the key class
Inheritance

Constructors

ExpandoWithFinalizer(FinalizerCallback<V> onFinalize, {bool debug = false})
Creates an ExpandoWithFinalizer.

Properties

debug → bool
Enables debug mode.
final
hashCode → int
The hash code for this object.
no setterinherited
onFinalize → FinalizerCallback<V>
User-provided callback invoked when a key is garbage-collected.
finalinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

containsKey(K key) → bool
Returns whether a value is currently associated with key.
createWrapper(K key, V value) → ExpandoValueWrapper<V>
Creates and stores a wrapper for the given key and value.
override
get(K key) → V?
Returns associated value if the key is still alive.
getWrapper(K key) → ExpandoValueWrapper<V>?
Returns the wrapper associated with key, if any.
override
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
onFinalizeError(Object error, StackTrace stackTrace) → void
Called when onFinalize throws.
inherited
put(K key, V value) → void
Associates value with key, replacing any existing association.
inherited
remove(K key) → V?
Removes the association for key, if present.
override
toString() → String
A string representation of this object.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited
operator [](K key) → V?
Returns the value associated with key. See get.
operator []=(K key, V value) → void
Associates value with key. See put.