A string component id or the numeric index of the component that should be initially activated within the container's layout on render. For example, activeItem: 'item-1' or activeItem: 0 (index 0 = the first item in the container's collection). activeItem only applies to layout styles that can display items one at a time (like Ext.layout.Accordion, Ext.layout.CardLayout and Ext.layout.FitLayout). Related to Ext.layout.ContainerLayout.activeItem.

True to animate the transition when the panel is collapsed, false to skip the animation (defaults to true if the Ext.Fx class is available, otherwise false).

The id of the node, a DOM node or an existing Element corresponding to a DIV that is already present in the document that specifies some structural markup for this component. When applyTo is used, constituent parts of the component can also be specified by id or CSS class name within the main element, and the component being created may attempt to create its subcomponents from that markup if applicable. Using this config, a call to render() is not required. If applyTo is specified, any value passed for renderTo will be ignored and the target element's parent node will automatically be used as the component's container.