How "Don't Repeat Yourself" in methods of a Controller in ASP.NET MVC? - asp.net-mvc

Question

within each methods of a controller , I have to execute a method.
public ActionResult Index1()
{
if (Foo(id, SessionManage.DataSession) )
return RedirectToAction("Page1");
Code4Index1();
return View();
}
public ActionResult Index2()
{
if (Foo(id, SessionManage.DataSession) )
return RedirectToAction("Page1");
Code4Index2();
return View();
}
public ActionResult Index3()
{
if (Foo(id, SessionManage.DataSession) )
return RedirectToAction("Page1");
Code4Index3();
return View();
}
public ActionResult Index4()
{
if (Foo(id, SessionManage.DataSession) )
return RedirectToAction("Page1");
Code4Index4();
return View();
}
Is there a smarter way than organize the code or I am forced to go against DRY concept?
I'd like not repeat the code for each method :
if (Foo(id, SessionManage.DataSession) )
return RedirectToAction("Page1");
Thanks to all.

Answer 1

Well, ASPNET has already the infrastructure for handling authorization so why not just use it?
Create a new attribute class, inherited from AuthorizeAttribute
Override the methods:
OnAuthorization: to perform your check
HandleUnauthorizedRequest: to decide whats the result view that the user will see.
Mark your controller methods with this attribute.
Your attribute may look like:
class MyCustomAuthorizeAttribute : AuthorizeAttribute
{
protected override void HandleUnauthorizedRequest(AuthorizationContext filterContext)
{
// Do whatever you want here, for example
//filterContext.Result = new whatever() ;
base.HandleUnauthorizedRequest(filterContext);
}
public override void OnAuthorization(AuthorizationContext filterContext)
{
if ( /* the request does not pass your checks */ )
throw new UnauthorizedAccessException();
}
}
And your controller code will look like:
[MyCustomAuthorize]
public ActionResult Index1()
{
return View();
}
[MyCustomAuthorize]
public ActionResult Index2()
{
return View();
}
[MyCustomAuthorize]
public ActionResult Index3()
{
return View();
}
[MyCustomAuthorize]
public ActionResult Index4()
{
return View();
}
You can also check this post for a more clear example:
https://stackoverflow.com/a/5663518/1413973

Answer 2

You can refactor your controller like this:
public ActionResult Index1()
{
return AccessDeniedRedirect();
}
public ActionResult Index2()
{
return AccessDeniedRedirect();
}
public ActionResult Index3()
{
return AccessDeniedRedirect();
}
public ActionResult Index4()
{
return AccessDeniedRedirect();
}
private ActionResult AccessDeniedRedirect()
{
if (Checks(id, SessionManage.DataSession))
return RedirectToAction("AccesDiened");
return View();
}