Get action info from ModelValidator

Question

I'm implementing a ModelValidator that needs to get reflected information from the executing action. Validation behavior will change depending on how action is decorated. Can I get that information?

gram · Answer 1 · 2011-06-18T19:10:03.543

1

The constructor for your ModelValidator should take a ControllerContext. You can use that object to determine what attributes your controller is decorated with like so:

context.Controller.GetType().GetCustomAttributes(typeof(YourAttribute), true).Length > 0

Edit:

You can also get a list of all attributes like so:

attributes = context.Controller.GetType().GetCustomAttributes(true);

So, a simple example for validating based on a specific attribute:

public class SampleValidator : ModelValidator {
    private ControllerContext _context { get; set; }

    public SampleValidator(ModelMetadata metadata, ControllerContext context, 
        string compareProperty, string errorMessage) : base(metadata, context) {
        _controllerContext = context;
    }

    public override IEnumerable<ModelValidationResult> Validate(object container) {
        if (_context.Controller.GetType().GetCustomAttributes(typeof(YourAttribute), true).Length > 0) {
            // do some custom validation
        }

        if (_context.Controller.GetType().GetCustomAttributes(typeof(AnotherAttribute), true).Length > 0) {
            // do something else
        }
    }
}

}

edited Jun 18 '11 at 19:10

answered Jun 18 '11 at 18:20

gram

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We are almost there. I need to get what attributes the executing action is decorated with. – Eduardo Jun 18 '11 at 18:34
That returns all attributes of controller. Which method? – Eduardo Jun 18 '11 at 18:58
I'm not sure what you're asking. I updated my answer to show a simple example of how this might work. – gram Jun 18 '11 at 19:12
Instead of _context.Controller I need to implement getExecutingActionMethodInfo() in this example: MethodInfo info = getExecutingActionMethodInfo(); if (info.GetCustomAttributes(typeof(YourAttribute), true).Length > 0) ... – Eduardo Jun 18 '11 at 22:02

score 0 · Answer 2 · answered Jun 19 '11 at 00:05

After decompiling System.Web.Mvc I got it:

protected override IEnumerable<ModelValidator> GetValidators(ModelMetadata metadata, ControllerContext context, IEnumerable<Attribute> attributes)
{
    ReflectedControllerDescriptor controllerDescriptor = new ReflectedControllerDescriptor(context.Controller.GetType());
    ReflectedActionDescriptor actionDescriptor = (ReflectedActionDescriptor) controllerDescriptor.FindAction(context, context.RouteData.GetRequiredString("action"));
    object[] actionAttributes = actionDescriptor.GetCustomAttributes(typeof(MyAttribute), true);
}

Eduardo: regarding your moderator response, you don't have to put your entire blog entry in your answer. Just summarize the important details of your blog entry, and provide a link. Answers with bare links (without a summary) suffer from several problems; they look like spam, and they suffer from link rot. — Robert Harvey, Jun 22 '11 at 14:31

Get action info from ModelValidator

2 Answers2