SPA (Single Page Application) is equipped with so-called Magistral-layout, which has been designed as SPA-container for clean internal SPA-navigation and possibility of explicit cancellation (abandoment by user) of server request invocation. Such cancellable busy-operation is realized here as semi-blocking visual procedure.

Magistral-layout is implemented with help of TypeScript (there is C# API for Blazor-client; .NET-classes: AFXUI.UMagistral and AFXUI.UMagistralMI). Magistral HTML (layout elements in markup) was intentionally built at topmost in wwwroot/index.html (instead of Razor-file) — for the sake of sense presence of embedded SPA-enhancement, as if it has been built-in into browser (for such perceptional effect).

Approximate structure of Magistral-layout (its visual elements):

1. Page scrollable content
   • Page scrollable DIV for user content
   • Vertical scrollable bar at the right edge of HTML-window
   • Automatic horizontal scroll-bar at window bottom
2. Tool panet (side-bar at the right)
   1. Busy indicator (animated image at top-right)
   2. Navigation drop-down menu (SPA)
   3. Home-page reference (SPA)
   4. Reload-page reference (SPA)
   5. Select all content reference
   6. Unselect anything rectangle (DIV)
   7. Escape panels (together with busy-indicator)
   8. Page-top / page-bottom arrows (scroll refs)
   9. Vertical page name (at right-bottom)
3. Operation popup indicator (at busy state)
4. Page content footer
   • Horizontal separator (HR)
   • Copyright and/or some other info