We just covered Custom Validation Methods, where we learned how to use CustomValidationAttribute to invoke a static (VB: Shared) method to perform validation.  Let’s talk about an alternate approach to custom validation though: creating custom, reusable validators by deriving from ValidationAttribute.  While it’s true that the custom validation methods used... [Read More]

In our last installment, we learned about the standard validators that ship in the System.ComponentModel.DataAnnotations assembly.  RequiredAttribute, RangeAttribute, StringLengthAttribute, and RegularExpressionAttribute all derive from ValidationAttribute and cover many common validation scenarios.  Every system has its own business rules though, and therefore it’s imperative that RIA Services allows you to create... [Read More]

RIA Services offers powerful features for flowing validation from your entity model all the way up to the Silverlight UI.  In fact, flowing your validation rules from the server into your form controls was one of the primary tenets of RIA Services V1, and our team did the work of... [Read More]

Over on our forums, many of you have reported difficulty with the ComboBox control when using RIA Services.  Kyle McClellan (@KyleMcClellan) suggested that we drill into various ComboBox scenarios to see what works well and what doesn’t.  Our goal was to produce some samples that address common scenarios, and to... [Read More]

Almost a year ago, I posted a lengthy article on how to implement Async Validation with RIA Services and DataForm.  It was hard; much harder than it should have been, and we all knew it.  Since then, things have changed, and async validation is a lot simpler.  Let’s take a... [Read More]