MappedEvent<V, T> class

A MappedEvent is useful when your event value must be transformed by some function that, usually, needs the store state. You must provide the event and a map-function. The map-function must be able to deal with the spent state (null or false, accordingly).

For example, if state.indexEvt = Event<int>(5) and you must get a user from it:

var mapFunction = (index) => index == null ? null : state.users[index];
Event<User> userEvt = MappedEvent<int, User>(state.indexEvt, mapFunction);
Inheritance

Constructors

MappedEvent(Event<V>? evt, T? mapFunction(V?))

Properties

evt ↔ Event<V>
getter/setter pair
hashCode → int
  • If two objects are equal according to the equals method, then hashcode of both must be the same. Since spent events are all equal, they should produce the same hashcode.
  • If two objects are NOT equal, hashcode may be the same or not, but it's better when they are not the same. However, events are mutable, and this could mean the hashcode of the state could be changed when an event is consumed. To avoid this, we make events always return the same hashCode.
    • no setterinherited
    isNotSpent → bool
    no setterinherited
    isSpent → bool
    no setteroverride
    mapFunction ↔ T? Function(V?)
    getter/setter pair
    runtimeType → Type
    A representation of the runtime type of the object.
    no setterinherited
    state → T?
    Returns the event state.
    no setteroverride

    Methods

    consume() → T?
    Returns the event state and consumes the event.
    override
    noSuchMethod(Invocation invocation) → dynamic
    Invoked when a nonexistent method or property is accessed.
    inherited
    toString() → String
    A string representation of this object.
    inherited

    Operators

    operator ==(Object other) → bool
    The StoreConnector has a distinct parameter which may be set to true. As a performance optimization, distinct:true allows the widget to be rebuilt only when the ViewModel changes. If this is not done, then every time any state in the store changes the widget will be rebuilt.
    inherited