# Event handlers Through the use of event handlers you can trigger an [action](https://docs.appfarm.io/reference/apps/actions) to run either automatically or due to user interaction. Automatic events occur when an app is in use, such as when an [app](https://docs.appfarm.io/reference/apps) or [view](https://docs.appfarm.io/reference/apps/ui/views) is loaded, or a [timer](https://docs.appfarm.io/apps/app-settings#timers). User interaction events can include clicking a [UI component,](https://docs.appfarm.io/library/ui-components) updating a value in a data input component, or running a [keyboard shortcut](https://docs.appfarm.io/apps/ui/views#keyboard-event-handlers). ## Automatic events
EventDescription
On App LoadTriggered when the app is loaded/refreshed after data sources have been populated but before the UI is shown to the user. Configured in App settings.
On App LoadedTriggered when the app is loaded/refreshed and after the UI is shown to the user. Configured in App settings.
On Online/On OfflineFor Offline Apps. Configured in App settings.
On Visible/On HiddenTriggered when an App goes inactive or active. Configured in App settings.
On Browser History ChangeCan be used to trigger an action when the browser history changes. Configured and documented in App settings.
On TimeoutTrigged when a timer expires. Configured in App settings.
On View Load/Dialog Open/Drawer OpenTriggered before a view is loaded/opened. Configured in view properties.
On View Loaded/Dialog Opened/Drawer OpenedTriggered after a view is loaded/opened. Configured in view properties.
On LoadTriggered after a component is loaded. Configured in component properties for Image and Animated component.
On CompleteTriggered after after a component has completed its purpose. Configured in component properties for Animated component.
## User interaction events User interaction events are configured in [UI components](https://docs.appfarm.io/library/ui-components). For details on how to add keyboard event handlers, see [Views](https://docs.appfarm.io/apps/ui/views#keyboard-event-handlers).
EventDescription
On [Location] ClickTriggered when the user clicks or taps on a component (like a Button) or part of a component (like a Table row). Can be used to make containers and Image components clickable. If used in a data iterator, the element clicked will contain the object in context.
On Hover StartTriggered when the mouse pointer enters a container. Use Conditional styles to style a component on hover.
On Hover EndTriggered when the mouse pointer leaves a container.
On Double ClickTriggered when double clicking a container
On Right ClickTriggered when right clicking a container
On Drag StartTriggered when a user starts to drag a component within a container that has Enable Draggable selected.
On DropTriggered when a user drops a component within a container that has Enable Drop Area selected.
On File PasteTriggered when a file is pasted on a container with Enable File Drop selected. Can be used to run an action with Create file object to upload the file.
On File DropTriggered when a file is dropped on a container with Enable File Drop selected. Can be used to run an action with Create file object to upload the file.
On File OverTriggered when a file is dragged over a container with Enable File Drop selected. Can be used to toggle visual feedback.
On File OutTriggered when a file is dragged over and then out of a container with Enable File Drop selected. Can be used to toggle visual feedback.
On Viewport EnterTriggered when a container with Enable Listener selected enters the viewport, usually on scroll.
On Viewport LeaveTriggered when a container with Enable Listener selected leaves the viewport, usually on scroll.
On FocusTriggered when a Text edit component receives focus due to a user clicking on or using the keyboard to select the component.
On Lost FocusTriggered when a Text edit component loses focus due to a user clicking away or using the keyboard to select another component.
On EnterTriggered when the Enter/Return key is pressed and a Text edit component has focus. Useful when the component is used for searching to execute the search.
On Value ChangeTriggered after a value has changed in a data input component. The previous value can be sent as an action param.
On OpenAvailable on UI Components Select and Multi select. Triggered when the droplist is opened.
On CloseAvailable on UI Components Select and Multi select. Triggered when the droplist is closed.