openai-aspnet-core/references/ui-razor-pages.md

Razor Pages

Primary docs: - https://learn.microsoft.com/aspnet/core/razor-pages/ - https://learn.microsoft.com/aspnet/core/tutorials/razor-pages/

Choose Razor Pages For Page-Centered Apps

Prefer Razor Pages when requests naturally map to pages, forms, and page-level handlers. This is a strong default for internal tools, CRUD apps, account flows, and admin surfaces.

Core Shape

Enable Razor Pages with:

• builder.Services.AddRazorPages();
• app.MapRazorPages();

Use the @page directive to turn a .cshtml file into an endpoint. Keep request logic in the paired PageModel class when the page is more than trivial.

Routing Model

• File system location defines the route by default
• Pages/Index.cshtml maps to /
• Pages/Store/Index.cshtml maps to /Store
• Keep folder structure meaningful because it becomes the URL structure

PageModel Guidance

• Use OnGet, OnPost, and named handlers for request processing
• Use bindable properties and model validation for forms
• Keep page models thin; move business logic into injected services
• Use Tag Helpers and model binding instead of manual request parsing

Good Fits

• form-heavy workflows
• dashboards and back-office applications
• simple content with server-side validation
• applications where a page is the primary navigation unit

Key Limitation

Do not rely on per-handler authorization with Razor Pages. Microsoft explicitly recommends using MVC controllers when different handlers on the same logical surface need different authorization behavior.

Preferred responses to that limitation:

• split the handlers into separate pages
• move the surface to MVC if action-level authorization is a better fit

Organizational Guidance

• Group related pages into folders
• Use partial views for repeated fragments
• Use areas only when the application has clear bounded sections
• Keep shared layout and page conventions centralized