Data Architecture DataView holds ref count on cache entry HTML Template Data Architecture View View Controls View Model (proxy) View Model (proxy) View Model Proxy kept in sync via PostMessage HTML and CSS is sanitized to remove untrusted JavaScript Shell IFrame Extension IFrame View Model Model Data View Model DataView DataView DataContext DataView holds ref count on cache entry Add IFrame isolation (to isolate extension JavaScript execution) Standard MVVM pattern View models load data using a DataView Model data cached in DataContext Disposed view model decrements ref count View composed of Controls, described by HTML template "fetch(...)" Unreferenced cache entries can be evicted Other view models also hold ref counts Ajax call to populate missing cache entry DataContext contains multiple DataCaches DataCache DataCache DataCache Model Data Result placed in the cache entry (in a DataSet) DataSet Cache entries are DataSets Base.Net.ajax(…) DataSet Service