MapSignal<K, V> class

Signal for Map with convenient mutation methods.

MapSignal provides reactive map operations while maintaining immutability. Each mutation creates a new map instance to trigger updates.

Basic Usage

final settings = MapSignal<String, dynamic>({'theme': 'light'});

// Add/Update entry
settings.put('theme', 'dark');

// Remove entry
settings.remove('theme');

// Clear all
settings.clear();

Binding to UI

Slot(
  connect: settings,
  to: (context, map) {
    return Text('Theme: ${map['theme']}');
  },
)
Inheritance

Constructors

MapSignal(Map<K, V> initial, {String? debugLabel, bool equals(Map<K, V> a, Map<K, V> b)?, Map<K, V> guard(Map<K, V> current, Map<K, V> next)?, VoidCallback? onListen, VoidCallback? onCancel})

Properties

debugLabel → String?
Debug label for identification in DevTools.
finalinherited
entries → Iterable<MapEntry<K, V>>
Get all entries.
no setter
equals → bool Function(Map<K, V> a, Map<K, V> b)?
Custom equality function to determine if value has changed.
finalinherited
guard → Map<K, V> Function(Map<K, V> current, Map<K, V> next)?
Value guard/transformer called before setting a new value.
finalinherited
hashCode → int
The hash code for this object.
no setterinherited
hasListeners → bool
Whether this atom has any listeners.
no setterinherited
initialValue → Map<K, V>
The initial value of the atom.
no setterinherited
isDisposed → bool
Whether this atom has been disposed.
no setterinherited
isEmpty → bool
Check if map is empty.
no setter
isNotEmpty → bool
Check if map is not empty.
no setter
keys → Iterable<K>
Get all keys.
no setter
length → int
Get length of map.
no setter
onCancel → VoidCallback?
Callback invoked when the last listener unsubscribes.
finalinherited
onListen → VoidCallback?
Callback invoked when the first listener subscribes.
finalinherited
previousValue → Map<K, V>?
The previous value of the atom (before the last change).
no setterinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
stream → Stream<Map<K, V>>
A broadcast stream of value changes.
no setterinherited
val → Map<K, V>
Short alias for the current value.
no setterinherited
value ↔ Map<K, V>
Override value getter to support dependency tracking for Computed.
getter/setter pairinherited
values → Iterable<V>
Get all values.
no setter

Methods

addListener(VoidCallback listener) → void
Adds a listener to be called when the value changes.
inherited
clear() → void
Clear all entries.
containsKey(K key) → bool
Check if key exists.
dispose() → void
Disposes the atom, removing all listeners.
inherited
emit(Map<K, V> val) → void
Assigns a new value and notifies listeners if the value changed.
inherited
mutate(void mutator(Map<K, V> map)) → void
Mutate the map in-place and notify listeners.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
notifyListeners() → void
Manually notifies all listeners.
inherited
onActive() → void
Called when the first listener is added.
inherited
onInactive() → void
Called when the last listener is removed.
inherited
put(K key, V value) → void
Put a key-value pair.
putAll(Map<K, V> entries) → void
Put multiple entries.
remove(K key) → V?
Remove a key.
removeListener(VoidCallback listener) → void
Removes a previously added listener.
inherited
reset() → void
Resets the atom to its initial value.
inherited
select<R>(R selector(Map<K, V> value)) → NeuronAtom<R>
Creates a new atom that selects a part of this atom's value.
inherited
subscribe(VoidCallback listener) → VoidCallback
Adds a listener and returns a callback that cancels the subscription when called.
inherited
toString() → String
A string representation of this object.
inherited
update(K key, V updater(V? value)) → void
Update value for key using function.

Operators

operator ==(Object other) → bool
The equality operator.
inherited
operator [](K key) → V?
Get value by key.