The variable type.
Constructs a CVar with the given initialValue.
The initialValue is used as the value before any
value is set or just after clear is called.
If provided, used to "aggregate" concurrently-set values, instead of picking one arbitrarily.
Serializer for set values. Defaults to [[DefaultSerializer]].
The children (registered Collab properties), keyed by name.
This map should only be read, not mutated. It is exposed to subclasses as a convenience for methods that loop over all children.
Internal (this/parent) use only.
This Collab's name, which distinguishes it among its siblings in the tree of Collabs.
Internal (this/parent) use only.
This Collab's parent in the tree of Collabs.
The ambient [[IRuntime]].
Use this to access utilities like [[IRuntime.replicaID]].
Internal (parent) use only.
By default, this method returns true if canGC returns true
on every child. Override to change this behavior.
See [[Collab.canGC]].
Resets this CVar to its initial state, so that its
value is the constructor's initialValue.
Returns all conflicting concurrently-set values. Their order is arbitrary but consistent across replicas.
If this CVar was just initialized or clear
was just called, this returns []. Otherwise, its first
element is the set value.
Emits an event, which triggers all the registered event handlers.
See [[CollabEventsRecord]] for advice on what events to emit.
This is a wrapper around [[EventEmitter.emit]] that forces events to extend [[CollabEvent]] and also emits an "Any" event.
Set to true to skip emitting an "Any" event.
Internal (parent) use only.
By default, this methods calls finalize on every child.
Override to change this behavior,
e.g., to add your own finalization steps
(but consider calling super.finalize()).
Internal (parent) use only.
Called by this Collab's parent to load saved state. See [[Collab.load]].
A CObject subclass may override this method to load additional state from [[Collab.save]] or to perform extra setup - e.g., refreshing functional views that were not automatically updated by children's load events. It is recommended to do so as follows:
load(savedStateTree: SavedStateTree | null, meta: SavedStateMeta) {
super.load(savedStateTree, meta);
// Process your extra saved state from savedStateTree.self.
const savedState = savedStateTree === null? null: savedStateTree.self!;
...
// Perform extra setup as needed.
...
}
Registers an event handler that is triggered when the event happens.
Name of the event to listen on.
Callback that handles the event.
If true, the event handler is triggered at most once (the next time the event happens), then unsubscribed.
An "off" function that removes the event handler when called.
Registers an event handler that is triggered when the event happens.
An "off" function that removes the event handler when called.
Registers a [[Collab]] property of this CObject with the given name, making it one of our children.
Typically, you will call this method during the constructor in the style:
this.foo = this.registerCollab("foo", (init) => new FooClass(init, constructor args...));
where readonly foo: FooClass; is a Collab property. See
Data Modeling
for examples.
Registrations must be identical across all replicas.
See also: CRuntime.registerCollab.
A name for this property, unique among
this class's registerCollab calls.
We recommend using the same name as the property,
but you can also use short strings to reduce
network usage ("", "0", "1", ...).
A callback that uses the given [[InitToken]] to construct the registered [[Collab]].
The registered Collab.
Internal (parent) use only.
Returns saved state describing the current state of this CObject. See [[Collab.save]].
A CObject subclass may override this method to save additional state. It is recommended to do so as follows:
save() {
const ans = super.save();
// Put your extra saved state in ans.self, which is otherwise unused.
ans.self = <subclass's saved state>;
return ans;
}
Broadcasts a message to other replicas of this Collab. The message will be delivered to all replicas' receive, including locally.
For convenience, the message may be expressed as a stack of
(Uint8Array | string),
instead of just a single Uint8Array. This is
useful for parents sending messages on behalf of their children;
see the implementation of [[CObject]] for an example.
The message to send, in the form of a stack of Uint8Arrays. Note that this method may mutate it in-place.
Sets the current value. Equivalent to this.value = value.
value
Generated using TypeDoc
A collaborative variable of type T.
A
CVar<T>represents an opaque value of type T. Set and get the value with value. If multiple users set the value concurrently, one of them is picked arbitrarily.Values must be internally immutable; mutating value internally will not change it on other replicas. To store (a reference to) a mutable value of type T, use a
CVar<CollabID<C>>, where C is a Collab representing T. (Example)See also: CBoolean, CCounter.