Class: DynamicValue

const dynVal = new declarative.DynamicValue(42);
console.log(dynVal.val);  // prints 42
dynVal.val = 25;          // changes the value to 25 and notifies all watchers.
console.log(dynVal.val);  // prints 25

Methods

unwatched (callback)

declarative.js:1062

Registers a callback for when the last watcher was removed, meaning that this dynamic value is now completely unwatched.

Name	Type	Description
callback	function	The callback to invoke.

update ()

declarative.js:1028

Notifies all watchers of this dynamic value about a value change. This method must be called explicitly after changing a value directly.

watch (watchCallback)declarative.DynamicValue.WatchHandle

declarative.js:964

Registers a callback for watching this dynamic value for changes and returns a watch handle.

The watch handle has a method unwatch to stop watching the value for changes.

Name	Type	Description
watchCallback	function	The callback to invoke on changes.

Returns:

Type	Description
declarative.DynamicValue.WatchHandle	The watch handle.

Example

Watch for changes

const dynVal = new declarative.DynamicValue(42);
dynVal.watch(v => console.log("The value changed to " + v.val);
++(dynval.val);
dynVal.update();           // prints "The value changed to 43"

watched (callback)

declarative.js:1068

Registers a callback for when the first watcher was added, meaning that this dynamic value is now being watched.

Name	Type	Description
callback	function	The callback to invoke.

Type Definitions

declarative.DynamicValue.WatchHandle

A dynamic value watch handle.

Properties:

Name	Type	Description
setEnabled	function	Enables or disables this watcher.
unwatch	function	Stops watching the dynamic value.
value	function	Returns the current value.