Event Objects
DevExtreme components define types that supply event argument data. Naming convention is the following: the argument type of the contentReady
event handler is ContentReadyEvent
.
Event objects are unions created from basic event types. This improves the readability of event definitions:
export type AppointmentTooltipShowingEvent = Cancelable & EventInfo<dxScheduler> & { readonly targetElement: DxElement; readonly appointments: AppointmentTooltipShowingAppointmentInfo[]; }; export type CellContextMenuEvent = NativeEventInfo<dxScheduler, MouseEvent | PointerEvent | TouchEvent> & { readonly cellData: any; readonly cellElement: DxElement; };
The example above reads as follows:
AppointmentTooltipShowing is a synthetic event which can be cancelled. The event object contains common synthetic event fields and 2 extra fields: targetElement and appointments.
CellContextMenu is a common native event which cannot be cancelled. The event object contains common native event fields and 2 extra fields: cellData and cellElement. Underlying native event may be a MouseEvent, PointerEvent, or TouchEvent.
Event Object Parts
Most event arguments have a core part, either EventInfo
or NativeEventInfo
. These types may include conditional elements for integration with third-party libraries.
Event part | Description |
---|---|
EventInfo | EventInfo is used for synthetic events. |
NativeEventInfo | NativeEventInfo is used for browser events. |
ItemInfo | Events involving collection items include an ItemInfo part. |
ChangedOptionInfo | OptionChanged event objects include ChangedOptionInfo . |
InitializedEventInfo | Events involving initialization use InitializedEventInfo . |
Cancelable | If an event argument type includes Cancelable , the event can be canceled by setting the cancel property. |
If you have technical questions, please create a support ticket in the DevExpress Support Center.