ASP.NET Core 2 Fundamentals

Activity: Writing a Custom Filter

Scenario You need to write a filter that will only allow the applied action on Sundays. How would you do that?

Aim To write a custom filter.

Steps for completion

1. Open your editor and write this code:

Go to https://goo.gl/9QKgbS to access the code.

public class SundayFilter : Attribute, IActionFilter{  public void OnActionExecuting(ActionExecutingContext context)  {    if (DateTime.Now.DayOfWeek != DayOfWeek.Sunday)    context.Result = new ContentResult()    {      Content = "Sorry only on sundays!"    };}  public void OnActionExecuted(ActionExecutedContext context)  {  // do something after the action executes  }}

Setting results in the filter causes short circuiting, so our action does not run.

2. Now, we can apply this attribute ...