CallbackProperty

A Property whose value is lazily evaluated by a callback function.

Name	Type	Description
`callback`	CallbackProperty~Callback	The function to be called when the property is evaluated.
`isConstant`	Boolean	`true` when the callback function returns the same value every time, `false` if the value will change.

readonlydefinitionChanged :Event

Gets the event that is raised whenever the definition of this property changes. The definition is changed whenever setCallback is called.

readonlyisConstant :Boolean

Gets a value indicating if this property is constant.

equals(other) → Boolean

Compares this property to the provided property and returns true if they are equal, false otherwise.

Name	Type	Description
`other`	Property	optional The other property.

true if left and right are equal, false otherwise.

getValue(time, result) → Object

Gets the value of the property.

Name	Type	Description
`time`	JulianDate	optional The time for which to retrieve the value. This parameter is unused since the value does not change with respect to time.
`result`	Object	optional The object to store the value into, if omitted, a new instance is created and returned.

The modified result parameter or a new instance if the result parameter was not supplied or is unsupported.

setCallback(callback, isConstant)

Sets the callback to be used.

Name	Type	Description
`callback`	CallbackProperty~Callback	The function to be called when the property is evaluated.
`isConstant`	Boolean	`true` when the callback function returns the same value every time, `false` if the value will change.

Callback(time, result) → Object

A function that returns the value of the property.

Name	Type	Description
`time`	JulianDate	optional The time for which to retrieve the value.
`result`	Object	optional The object to store the value into, if omitted, a new instance is created and returned.

The modified result parameter or a new instance if the result parameter was not supplied or is unsupported.