SharePoint 2013 App Part MVC View Presents 404

Question

I have developed a high-trust provider hosted app using the MVC framework to display a series of employee-focused KPI data widgets. Everything has been highly successful until I began implemented the App Parts (formally web parts -- iFrame views of the remote web application, for the uninitiated). The problem is specifically related to the routing, as I am able to successful view the application via the default route of each controller (using MVC attribute routing).

Results:

• Any action result specified in [Route("action=TheView")] is a success.
  • Elements.xml example:
    • Src="https://apps.domain.com/Dashboard/TheView/?{Standard Tokens}" is a success
    • Src="https://apps.domain.com/Dashboard/TheOtherView/?{Standard Tokens}" is a 404 The Resource can not be found
    • Both URLs are accessible via web browser. Even explicitly revisiting the URL found in the web traffic logs (w/ parameters) is successful outside the context of SharePoint.

I certainly hope there is just some glaring, fundamental misunderstanding about using attribute routing in this scenario that I am not considering. However, I have received no useful error messages and none of my troubleshooting efforts have been successful.

Any help would be much appreciated.

Answer 1

You mentioned you are using attribute routing.

Are you by any chance using [HttpGet] attribute on your ActionResult?

SharePoint addin does a POST to your web application. So just remove [HttpGet] attribute and let MVC handle it or change it to [HttpPost] if it doesn't work.