rspec/rules/S3993/rule.adoc

== Why is this an issue?

When defining custom attributes, ``++System.AttributeUsageAttribute++`` must be used to indicate where the attribute can be applied. This will determine its valid locations in the code.


=== Noncompliant code example

[source,text]
----
using System;

namespace MyLibrary
{

   public sealed class MyAttribute :Attribute // Noncompliant
   {
      string text;

      public MyAttribute(string myText)
      {
         text = myText;
      }
      public string Text
      {
         get 
         {
            return text;
         }
      }
   }
}
----


=== Compliant solution

[source,text]
----
using System;

namespace MyLibrary
{

   [AttributeUsage(AttributeTargets.Class | AttributeTargets.Enum | AttributeTargets.Interface | AttributeTargets.Delegate)]
   public sealed class MyAttribute :Attribute
   {
      string text;

      public MyAttribute(string myText)
      {
         text = myText;
      }
      public string Text
      {
         get 
         {
            return text;
         }
      }
   }
}
----