What happened
In versions prior to v19.2, collapsible layout card groups are natively supported only in XAF ASP.NET and Mobile apps.
To support this highly requested feature in XAF WinForms apps, we introduced the IsCollapsibleGroup and IsGroupCollapsed properties into the platform-agnostic IModelLayoutGroup interface. In the XAF Web applications the IsCollapsibleGroup property is available in the Model Editor only if the IModelViewLayoutElementWeb.IsCardGroup property is set to True.
Why we did this
These changes allow XAF developers to configure this popular functionality once for all supported platforms without writing any custom code.
Collapsible layout groups with state management support is an alternative to layout tabs to optimize space on complex detail forms - XAF developer teams creating complex enterprise apps should value that usability enhancement.
How much will that affect me
In the Model Editor invoked for Web projects, the IModelLayoutGroupWeb.IsCollapsibleCardGroup and IModelLayoutGroupWeb.IsCardGroupCollapsed properties are hidden. In the Model Editor invoked for Mobile projects, the IModelLayoutCollapsibleGroupMobile.IsCollapsible and IModelLayoutCollapsibleGroupMobile.IsCollapsed properties are hidden. Use the IModelLayoutGroup.IsCollapsibleGroup and IModelLayoutGroup.IsGroupCollapsed properties instead in both the Model Editor and code. Values of old properties, customized in previous versions, will automatically be migrated to new platform-agnostic properties using the Convert Application Model Differences mechanism - the majority of XAF developers should not be affected.