EffectCell<T> class

A cell used for running side effects and observing the result.

This cell evaluates to the value of its argument cell argCell while making the following guarantees:

The value of argCell is only referenced when it notifies this cell that its value has changed.
The value of argCell is referenced at most once per value change notification.

This allows a side effect to be placed in the value computation function of the argument cell, since it is guaranteed that the side effect will only be run when triggered by the dependency cells, and will not be run more than necessary.

The result of the side effect can be observed by observing this cell.

NOTE: Accessing the value results in an UninitializeCellError being thrown until the first value change notification. This exception is also thrown when value is accessed while this cell is inactive.

IMPORTANT: These guarantees hold if the argument cell only calls its computation function when its value is referenced. If the argument cell calls its computation function even when its value is not referenced, then these guarantees no longer hold.

It should also be noted that these guarantees hold only when interacting with this cell via the cell returned by this method.

Constructors

EffectCell(ValueCell<T> argCell): Create a "side effect" cell for a given argument cell.

Properties

argCell → ValueCell<T>: The observed cell
finalinherited
asyncState → ValueCell<AsyncState<T>>: Available on FutureCell<T>, provided by the WaitCellExtension extension
A cell that evaluates to the AsyncState of the Future in this cell.
no setter
awaited → ValueCell<T>: Available on FutureCell<T>, provided by the WaitCellExtension extension
A cell that awaits the Future held in this.
no setter
cellList → ValueCell<Iterable<ValueCell<T>>>: Available on ValueCell<List<T>>, provided by the ListCellExtension extension
Returns a cell which wraps the elements of the List held in this cell in ValueCells.
no setter
changesOnly → bool: Should the observers only be notified if this cell's value has changed?
finalinherited
effectCell → ValueCell<T>: Available on ValueCell<T>, provided by the EffectCellExtension extension
Create a cell for observing side effects defined in this cell.
no setter
entries → ValueCell<Iterable<MapEntry<K, V>>>: Available on ValueCell<Map<K, V>>, provided by the MapCellExtension extension
Returns a cell which evaluates to Map.entries applied on the value in this cell.
no setter
equalityCellFactory → EqualityCellFactory: Return a factory for creating equality and inequality comparison cells.
no setterinherited
error → ValueCell: Available on ValueCell<Maybe<T>>, provided by the MaybeCellExtension extension
A cell which evaluates to the error of the Maybe.
no setter
first → ValueCell<T>: Available on ValueCell<Iterable<T>>, provided by the IterableCellExtension extension
Returns a cell which evaluates to Iterable.first applied on the value in this cell.
no setter
hashCode → int: The hash code for this object.
no setterinherited
hasState → bool: Does this cell have a state?
no setterinherited
inDays → ValueCell<int>: Available on ValueCell<Duration>, provided by the DurationCellExtension extension
The duration in units of days, see Duration.inDays
no setter
inHours → ValueCell<int>: Available on ValueCell<Duration>, provided by the DurationCellExtension extension
The duration in units of hours, see Duration.inHours
no setter
inMicroseconds → ValueCell<int>: Available on ValueCell<Duration>, provided by the DurationCellExtension extension
The duration in units of microseconds, see Duration.inMicroseconds
no setter
inMilliseconds → ValueCell<int>: Available on ValueCell<Duration>, provided by the DurationCellExtension extension
The duration in units of milliseconds, see Duration.inMilliseconds
no setter
inMinutes → ValueCell<int>: Available on ValueCell<Duration>, provided by the DurationCellExtension extension
The duration in units of minutes, see Duration.inMinutes
no setter
inSeconds → ValueCell<int>: Available on ValueCell<Duration>, provided by the DurationCellExtension extension
The duration in units of seconds, see Duration.inSeconds
no setter
isCompleted → ValueCell<bool>: Available on FutureCell<T>, provided by the WaitCellExtension extension
A cell that is true when the Future in this has completed, false otherwise.
no setter
isEmpty → ValueCell<bool>: Available on ValueCell<Iterable<T>>, provided by the IterableCellExtension extension
Returns a cell which evaluates to Iterable.isEmpty applied on the value in this cell.
no setter
isEmpty → ValueCell<bool>: Available on ValueCell<Map<K, V>>, provided by the MapCellExtension extension
Returns a cell which evaluates to Map.isEmpty applied on the value in this cell
no setter
isFinite → ValueCell<bool>: Available on ValueCell<num>, provided by the NumericExtension extension

no setter
isInfinite → ValueCell<bool>: Available on ValueCell<num>, provided by the NumericExtension extension

no setter
isNaN → ValueCell<bool>: Available on ValueCell<num>, provided by the NumericExtension extension

no setter
isNegative → ValueCell<bool>: Available on ValueCell<Duration>, provided by the DurationCellExtension extension
Returns a cell, the value of which is true if this is negative, see Duration.isNegative.
no setter
isNotEmpty → ValueCell<bool>: Available on ValueCell<Iterable<T>>, provided by the IterableCellExtension extension
Returns a cell which evaluates to Iterable.isNotEmpty applied on the value in this cell.
no setter
isNotEmpty → ValueCell<bool>: Available on ValueCell<Map<K, V>>, provided by the MapCellExtension extension
Returns a cell which evaluates to Map.isNotEmpty applied on the value in this cell
no setter
key ↔ dynamic: Key which uniquely identifies the cell
latefinalinherited
keys → ValueCell<Iterable<K>>: Available on ValueCell<Map<K, V>>, provided by the MapCellExtension extension
Returns a cell which evaluates to Map.keys applied on the value in this cell.
no setter
last → ValueCell<T>: Available on ValueCell<Iterable<T>>, provided by the IterableCellExtension extension
Returns a cell which evaluates to Iterable.last applied on the value in this cell.
no setter
length → ValueCell<int>: Available on ValueCell<Map<K, V>>, provided by the MapCellExtension extension
Returns a cell which evaluates to Map.length applied on the value in this cell
no setter
length → ValueCell<int>: Available on ValueCell<Iterable<T>>, provided by the IterableCellExtension extension
Returns a cell which evaluates to Iterable.length applied on the value in this cell.
no setter
notNull → ValueCell<T>: Available on ValueCell<T?>, provided by the NullCheckExtension extension
A cell that is guaranteed to hold a non-null value.
no setter
peek → ValueCell<T>: Available on ValueCell<T>, provided by the PeekCellExtension extension
Use the value of this without reacting to changes.
no setter
previous → ValueCell<T>: Available on ValueCell<T>, provided by the PrevValueCellExtension extension
Return a cell which holds the previous value of this cell.
no setter
reversed → ValueCell<Iterable<T>>: Available on ValueCell<List<T>>, provided by the ListCellExtension extension
Returns a cell which evaluates to List.reversed applied on the value in this cell.
no setter
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited
sign → ValueCell<num>: Available on ValueCell<num>, provided by the NumericExtension extension

no setter
single → ValueCell<T>: Available on ValueCell<Iterable<T>>, provided by the IterableCellExtension extension
Returns a cell which evaluates to Iterable.single applied on the value in this cell.
no setter
state → StoreCellState<T>?: The current state of the cell, or null if the cell is inactive.
no setterinherited
unwrap → ValueCell: Available on ValueCell<Maybe<T>>, provided by the MaybeCellExtension extension
A cell which evaluates to the unwrapped value (by Maybe.unwrap) of the Maybe.
no setter
value → T: The cell's value
no setteroverride
values → ValueCell<Iterable<V>>: Available on ValueCell<Map<K, V>>, provided by the MapCellExtension extension
Returns a cell which evaluates to Map.values applied on the value in this cell.
no setter
wait → ValueCell<T>: Available on FutureCell<T>, provided by the WaitCellExtension extension
Return a cell that awaits the Future held in this.
no setter
waitLast → ValueCell<T>: Available on FutureCell<T>, provided by the WaitCellExtension extension
A cell that awaits the Future held in this.
no setter
whenReady → ValueCell<T>: Available on ValueCell<T>, provided by the ErrorCellExtension extension
Create a cell that evaluates to ValueCell.none() while the cell's value is uninitialized.
no setter

Methods

abs() → ValueCell<num>: Available on ValueCell<num>, provided by the NumericExtension extension
abs() → ValueCell<Duration>: Available on ValueCell<Duration>, provided by the DurationCellExtension extension
Returns a cell holding a Duration of the same length as this but positive, see Duration.abs.
addObserver(CellObserver observer) → void: Register an observer of the cell to be called when the cell's value changes.
inherited
and(ValueCell<bool> other) → ValueCell<bool>: Available on ValueCell<bool>, provided by the BoolCellExtension extension
Create a new cell which is the logical and of this and other.
apply(U fn(T value), {dynamic key}) → ValueCell: Available on ValueCell<T>, provided by the ComputeExtension extension
Create a new cell, with a value which is computed by applying a function on this cell's value
call() → T: Retrieve the value of the cell.
inherited
cast<R>() → ValueCell<List<R>>: Available on ValueCell<List<T>>, provided by the ListCellExtension extension
Returns a cell which evaluates to List.cast<R>() applied on the value in this cell.
cast<R>() → ValueCell<Iterable<R>>: Available on ValueCell<Iterable<T>>, provided by the IterableCellExtension extension
Returns a cell which evaluates to Iterable.cast<R>() applied on the value in this cell.
chain(void action(), {dynamic key}) → ActionCell: Available on ValueCell<void>, provided by the ActionCellExtension extension
Create an action cell that is chained to this cell.
coalesce(ValueCell<T> ifNull) → ValueCell<T>: Available on ValueCell<T?>, provided by the NullCheckExtension extension
Replace null values in this cell with value of another cell.
contains(ValueCell elem) → ValueCell<bool>: Available on ValueCell<Set<T>>, provided by the SetCellExtension extension
Returns a cell that evaluates to true if the Set contains elem.
containsAll(ValueCell<Iterable> elems) → ValueCell<bool>: Available on ValueCell<Set<T>>, provided by the SetCellExtension extension
Returns a cell that evaluates to true if the Set contains elems.
containsKey(ValueCell key) → ValueCell<bool>: Available on ValueCell<Map<K, V>>, provided by the MapCellExtension extension
Returns a cell which evaluates to true if the Map held in this cell contains the key key.
containsValue(ValueCell val) → ValueCell<bool>: Available on ValueCell<Map<K, V>>, provided by the MapCellExtension extension
Returns a cell which evaluates to true if the Map held in this cell contains the value val.
createState() → CellState<StatefulCell>: Create the CellState for this cell.
override
delayed(Duration delay) → FutureCell<T>: Available on ValueCell<T>, provided by the DelayCellExtension extension
Create a cell which notifies its observers, for value changes in this, after a delay.
dumpState(CellValueCoder coder) → Object?: Dump the state of the cell to a value.
inherited
effect<T>(T fn(), {dynamic key}) → ValueCell<T>: Available on ValueCell<void>, provided by the ActionCellEffectExtension extension
Create a cell with a side effect that is run whenever this cell is triggered..
eq(ValueCell other) → ValueCell<bool>: Returns a new ValueCell which compares the value of this cell to another cell for equality.
inherited
error<E extends Object>({bool all = false}) → ValueCell<E?>: Available on ValueCell<T>, provided by the ErrorCellExtension extension
Create a cell which captures exceptions thrown during the computation of this cell.
hold() → CellHolder: Available on ValueCell, provided by the CellHolderExtension extension
Ensure that this cell is active.
initialValue(ValueCell<T> value) → ValueCell<T>: Available on ValueCell<T>, provided by the ErrorCellExtension extension
Returns a cell that evaluates to the value of value when the value of this is uninitialized.
loadingValue(ValueCell<T> value) → ValueCell<T>: Available on ValueCell<T>, provided by the ErrorCellExtension extension
Returns a cell that evaluates to the value of value while an async value is loading..
map<E>(E toElement(T e)) → ValueCell<Iterable<E>>: Available on ValueCell<Iterable<T>>, provided by the IterableCellExtension extension
Returns a cell which evaluates to Iterable.map() applied on the value in this cell.
mapCells<E>(E fn(T e)) → ValueCell<Iterable<ValueCell<E>>>: Available on ValueCell<List<T>>, provided by the ListCellExtension extension
Apply a function on the value of every cell in cellList.
mutableApply(U fn(T), void reverse(U), {dynamic key, bool changesOnly = false}) → MutableCell: Available on ValueCell<T>, provided by the ComputeExtension extension
Create a new mutable cell, with a value that is a function of this cell's value.
neq(ValueCell other) → ValueCell<bool>: Returns a new ValueCell which compares the value of this cell to another cell for inequality.
inherited
nextValue() → Future<T>: Available on ValueCell<T>, provided by the ValueChangeExtension extension
Returns a Future that completes with the next value of this cell, when it is updated.
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
not() → ValueCell<bool>: Available on ValueCell<bool>, provided by the BoolCellExtension extension
Create a new cell which is the logical not of this.
observe() → void: Track this cell as an argument of the current compute/watch function.
inherited
onError<E extends Object>(ValueCell<T> other) → ValueCell<T>: Available on ValueCell<T>, provided by the ErrorCellExtension extension
Create a cell which handles exceptions thrown while computing the value of this.
or(ValueCell<bool> other) → ValueCell<bool>: Available on ValueCell<bool>, provided by the BoolCellExtension extension
Create a new cell which is the logical or of this and other.
remainder(ValueCell<num> other) → ValueCell<num>: Available on ValueCell<num>, provided by the NumericExtension extension
removeObserver(CellObserver observer) → void: Remove an observer that was previously registered with addObserver.
inherited
restoreState(Object? state, CellValueCoder coder) → void: Restore the state of the cell.
inherited
select<T>(ValueCell<T> ifTrue, [ValueCell<T>? ifFalse]) → ValueCell<T>: Available on ValueCell<bool>, provided by the BoolCellExtension extension
Create a new cell which selects between the values of two cells based on this.
store({bool changesOnly = false}) → StoreCell<T>: Available on ValueCell<T>, provided by the StoreCellExtension extension
Return a ValueCell which stores the value of this cell in memory.
toList() → ValueCell<List<T>>: Available on ValueCell<Iterable<T>>, provided by the IterableCellExtension extension
Returns a cell which evaluates to Iterable.toList applied on the value in this cell.
toSet() → ValueCell<Set<T>>: Available on ValueCell<Iterable<T>>, provided by the IterableCellExtension extension
Returns a cell which evaluates to Iterable.toSet applied on the value in this cell.
toString() → String: A string representation of this object.
inherited
transform() → ValueCell: Available on ValueCell<T>, provided by the TransformExtension extension
untilFalse() → Future<void>: Available on ValueCell<bool>, provided by the BoolValueChangeExtension extension
Returns a Future that completes when the value of this cell is false.
untilTrue() → Future<void>: Available on ValueCell<bool>, provided by the BoolValueChangeExtension extension
Returns a Future that completes when the value of this cell is true.
untilValue(U value) → Future<void>: Available on ValueCell<T>, provided by the ValueChangeExtension extension
Returns a Future that completes when the value of this cell equals value.

Operators

operator %(ValueCell<num> other) → ValueCell<num>: Available on ValueCell<num>, provided by the NumericExtension extension
operator *(ValueCell<num> factor) → ValueCell<Duration>: Available on ValueCell<Duration>, provided by the DurationCellExtension extension
Returns a cell which holds the multiplication of this by factor.
operator *(ValueCell<num> other) → ValueCell<num>: Available on ValueCell<num>, provided by the NumericExtension extension
operator +(ValueCell<Duration> other) → ValueCell<Duration>: Available on ValueCell<Duration>, provided by the DurationCellExtension extension
Returns a cell which holds the sum of this and other.
operator +(ValueCell<num> other) → ValueCell<num>: Available on ValueCell<num>, provided by the NumericExtension extension
operator -(ValueCell<Duration> other) → ValueCell<Duration>: Available on ValueCell<Duration>, provided by the DurationCellExtension extension
Returns a cell which holds the subtraction of other from this.
operator -(ValueCell<num> other) → ValueCell<num>: Available on ValueCell<num>, provided by the NumericExtension extension
operator /(ValueCell<num> other) → ValueCell<num>: Available on ValueCell<num>, provided by the NumericExtension extension
operator <(ValueCell<Duration> other) → ValueCell<bool>: Available on ValueCell<Duration>, provided by the DurationCellExtension extension
Returns a cell of which the value is true if this is less than other
operator <(ValueCell<num> other) → ValueCell<bool>: Available on ValueCell<num>, provided by the NumericExtension extension
operator <=(ValueCell<Duration> other) → ValueCell<bool>: Available on ValueCell<Duration>, provided by the DurationCellExtension extension
Returns a cell of which the value is true if this is less than or equal to other
operator <=(ValueCell<num> other) → ValueCell<bool>: Available on ValueCell<num>, provided by the NumericExtension extension
operator ==(Object other) → bool: The equality operator.
inherited
operator >(ValueCell<Duration> other) → ValueCell<bool>: Available on ValueCell<Duration>, provided by the DurationCellExtension extension
Returns a cell of which the value is true if this is greater than other
operator >(ValueCell<num> other) → ValueCell<bool>: Available on ValueCell<num>, provided by the NumericExtension extension
operator >=(ValueCell<Duration> other) → ValueCell<bool>: Available on ValueCell<Duration>, provided by the DurationCellExtension extension
Returns a cell of which the value is true if this is greater than or equal to other
operator >=(ValueCell<num> other) → ValueCell<bool>: Available on ValueCell<num>, provided by the NumericExtension extension
operator [](ValueCell<int> index) → ValueCell<T>: Available on ValueCell<List<T>>, provided by the ListCellExtension extension
Returns a cell with a value equal to the element at index in the List held in this cell.
operator [](ValueCell key) → ValueCell<V?>: Available on ValueCell<Map<K, V>>, provided by the MapCellExtension extension
Returns a cell which evaluates to the value of the entry with key key.
operator unary-() → ValueCell<Duration>: Available on ValueCell<Duration>, provided by the DurationCellExtension extension
Returns a cell which holds the negation of this.
operator unary-() → ValueCell<num>: Available on ValueCell<num>, provided by the NumericExtension extension
operator ~/(ValueCell<int> quotient) → ValueCell<Duration>: Available on ValueCell<Duration>, provided by the DurationCellExtension extension
Returns a cell which holds the division of this by quotient.
operator ~/(ValueCell<num> arg) → ValueCell<num>: Available on ValueCell<num>, provided by the NumericExtension extension

EffectCell<T> class

Constructors

Properties

Methods

Operators

live_cells library