Question

I am working on a framework that uses some Attribute markup. This will be used in an MVC project and will occur roughly every time I view a specific record in a view (eg /Details/5)

I was wondering if there is a better/more efficient way to do this or a good best practices example.

At any rate, I have an a couple of attributes e.g:

[Foo("someValueHere")]
String Name {get;set;}

[Bar("SomeOtherValue"]
String Address {get;set;}

What is the most efficient way/best practice to look for these attributes/Act on their values?

I am currently doing something like this:

[System.AttributeUsage(AttributeTargets.Property)]
class FooAttribute : Attribute
{

    public string Target { get; set; }

    public FooAttribute(string target)
    {
        Target = target;
    }
}

And in my method where I act on these attributes(simplified example!):

public static void DoSomething(object source)
{
    //is it faster if I make this a generic function and get the tpe from T?
    Type sourceType = source.GetType();

    //get all of the properties marked up with a foo attribute
    var fooProperties =  sourceType
      .GetProperties()
      .Where(p => p.GetCustomAttributes(typeof(FooAttribute), true)
      .Any())
      .ToList();

    //go through each fooproperty and try to get the value set
    foreach (var prop in fooProperties)
    {          
        object value = prop.GetValue(source, null);
        // do something with the value
        prop.SetValue(source, my-modified-value, null);
     }
 }

Answer 1

Attribute.GetCustomAttribute and PropertyInfo/MemberInfo.GetCustomAttribute is the recommended way of getting at attribute objects.

Although, I wouldn’t normally enumerate all properties with attributes; you generally want to work a particular attribute so you’d just call GetCustomAttribute directly.If you’re looking for attributes on any of your properties, enumerating those properties looking for attributes based on GetCustomAttribute() the way you’re doing it, is the best way to do it.