Post Redirect Get in ASP.NET MVC And Validation With Restful URLs

Question

I have a restful URL for the action of editing a page. This is implemented on the controller as an Edit method, which accepts GET requests and an Edit method that accepts PO

Answer 1

You should only do the redirect if the form information is valid; in the case of submission errors, return the view from the same Edit method.

Doing it this way is compliant with PRG, because if your model is invalid, you are not allowing any changes to be made to the state of objects on the server. PRG is designed primarily to prevent multiple posts that can change the state of server objects (e.g., business objects, database tables, etc.) in unpredictable ways; in your validation example, however, the user can hit resubmit as many times as they want and they will always be sent back to the initial view with validation errors--nothing on the server changes. Therefore, you have it right: only issue the Redirect if your model passes validation in your presentation tier.