Search

Jeff Handley has some exciting news - WCF RIA Services V1.0 SP1 Beta and WCF RIA Services Toolkit October 2010 have been just released.

Source: Jeff Handley's Blog

This release has a bunch of bug fixes; it is a Service Pack after all. But showing a list of obscure bugs is not very exciting, so instead, let’s look at the more notable updates we’ve made. Please keep in mind that this is a Beta release, however it does have a Go-Live license.

We tweet all news and content updates - follow us on Twitter! 

Source: Jeff Handley's Blog

Although ValidationContext exists within the System.ComponentModel.DataAnnotations assembly in both .NET 4.0+ and Silverlight 3+, the class was introduced by the RIA Services team. While designing the RIA Services validation system, we considered scenarios where validation logic is based on factors outside the validation method itself. This can range from the user’s settings to UI state to other records within the system. In addition to the object and property a validator is being executed against, validators much be able to reach back into the system to extract whatever data is needed.

We tweet all news and content updates - follow us on Twitter! 

Jeff Handley has two more posts from his RIA Services Validation series, in which he discusses how to use ValidationContext.

In our last post, we learned how ValidationContext can be used to provide and consume state and services for validation methods to use. Now, let’s take a quick look at how validation methods can actually use this information. I’m going to include a bunch of code in this post, and I will rely on the code to be rather self-explanatory.

We tweet all news and content updates - follow us on Twitter! 

Source: Jeff Handley's Blog

In my last post, I went over some cross-field validation scenarios and provided some sample code, including a CompareValidatorAttribute. We’ve now covered single-field validation and cross-field validation, but there’s yet another level of validation supported by RIA Services—Entity-Level validation. As you’ll see in this post, entity-level validation is very similar to what we’ve already seen.

Source: Jeff Handley's Blog

In this post, I’m going to assume you now understand how to write cross-tier validation methods and attributes. The code shown should be saved in a .shared.cs file so that it is automatically compiled into your Silverlight project.

Source: Jeff Handley's Blog

My goal with this blog post series is to provide an end-to-end tour of how RIA Services validation works and how you can leverage its capabilities to build rich, responsive applications. A key factor for making the most of validation is fully understanding when and how RIA Services invokes your validation rules. Awareness of the various validation triggers will help you implement your validators so they are fired as you expect, when you expect.

Source: Jeff Handley's Blog

Since the beginning of the RIA Services project, a primary tenet was to propagate validation rules defined on the server up to the client, integrating the validation directly into the Silverlight UI. This came to fruition with RIA Services v1.0 and you can in fact apply an attribute to your model on the server and automatically get instant client-side validation of data entry on even the simplest of Textbox controls. In fact, some validation rules are inferred from your data model directly. This is a feat that many other frameworks have attempted to accomplish, but I believe RIA Services has one of the most successful implementations of the concept.

• RIA Services Validation: Custom Validation Methods
• RIA Services Validation: Custom Reusable Validators 

  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 by [CustomValidation] could certainly be reusable, I tend to think of that approach as a light-weight way to call specific business logic routines for validation. The approach we’re about to see is what I use when I’m creating an inventory of validators to be reused throughout my project(s).

Source: Jeff Handley's Blog

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 getting validation integrated deeply into Silverlight, long before RIA Services was released. In this post we’ll take a look at the standard validators that are offered.