[Overview][Constants][Types][Classes][Procedures and functions][Variables][Index] | Reference for unit 'Classes' (#rtl)

# IFPObserved.FPONotifyObservers

Notify all observers

## Declaration

Source position: classesh.inc line 171

`procedure IFPObserved.FPONotifyObservers(`
`ASender: TObject;`
`AOperation: TFPObservedOperation;`
`Data: Pointer`
`);`

## Description

FPONotifyObservers notifies all observers of the object that a change has occurred. It calls FPOObservedChanged on the IFPObserver interface of all attached objects, and passes on ASender (normally this is Self), AOperation and Data. What Data is, depends on the implementor of the interface.

There is no guaranteed order in which the change notifications are delivered to the observers. This is an implementation-specific detail, which should not be relied upon in any way.

## See also

IFPObserver |  | Interface for an object to observe other objects.
FPOObservedChanged |  | Entry point for change notifications
FPODetachObserver
FPOAttachObserver