Comments on: ASP.NET MVC Tip #3: Client-side form validation made easy – Part 1

By: ASP.NET MVC Tip #4: Client-side form validation made easy – Part 2 | devermind.com

Mon, 11 Jan 2010 13:00:55 +0000

[...] my previous article about ASP.NET MVC Client-Side validation, I showed how to set up your project so that you [...]

By: Adrian Grigore

Adrian Grigore — Sat, 12 Dec 2009 09:29:32 +0000

@Olivier: Yes, that’s what I mean by entity-based validation. I am going to show this in the next article. I had planned to write this MUCH earlier, but lately I am very busy at work…

By: Olivier

Olivier — Fri, 11 Dec 2009 22:09:59 +0000

Hi Adrian,
it is a good one too . Did you manage to solve this issue: when a user change some of his information but not is email, the validation return an error because the email is already used (email value display on form = email stored in the repository). so basically if we take the assumption that the username cannot change once a user is created, any update operation could validate against it. So if a user update his profile, 2 pieces of information need to be sent over the server email + username when the email field validation occurs. So if the email value sent for uniqueness validation match the current username no error message should be triggered.

By: Adrian Grigore

Adrian Grigore — Fri, 11 Dec 2009 15:26:41 +0000

Good point, Olivier. I’ve noticed this problem when working on my current project too since I wrote the article. Note that you can also get away without using form ids:

var validator=$(wrappedElement[0]).closest(”form”).validate();

By: Olivier

Olivier — Thu, 10 Dec 2009 21:23:19 +0000

Hi Adrian,
it is very nice piece of work.
I’ve just encounter an issue when you get a page with multiple forms. you get an javascript error on the call of jquery.validate. To fix it I’ve change $(”form”).validate().element(wrappedElement); by $(”#” + element.form.id).validate().element(wrappedElement); . Obviously you need to id your forms.

By: Dan

Dan — Mon, 30 Nov 2009 10:40:24 +0000

Hi Adrian,

Great post, however I also would give my right arm for the ‘validating entire business entities ‘ post !!!

All the best.

By: Shayne

Shayne — Wed, 25 Nov 2009 17:40:49 +0000

Regarding this: “This approach only works for Validation Attributes applied to properties, not to entire business entities. I’ll discuss a similar approach for validating entire business entities next week in the second part of this article.”

I too am patiently waiting for the follow-up article. Please find some time to post it Adrian.

Thanks for the brilliant work so far!

By: Adrian Grigore

Adrian Grigore — Tue, 27 Oct 2009 23:18:48 +0000

Thanks for the detailed upgrading list, Glen! I’m sure it will come in handy when I upgrade to ASP.NET MVC 2

By: Glenn

Glenn — Tue, 27 Oct 2009 18:55:54 +0000

Aha! I incorrectly assumed that since I stepped through the process in the debugger and there was no exception, the method returned a result properly. However, when I directly accessed the validator, this is what greeted me:

This request has been blocked because sensitive information could be disclosed to third party web sites when this is used in a GET request. To allow GET requests, set JsonRequestBehavior to AllowGet.

Brand new in MVC2. Sadly I even remember reading about that (potential security vulnerability) and didn’t consider it.

So, allow me to give you step #6 that seems to get the property validation working in VS2010 Beta 2 / MVC2:

6. On RemoteValidationController, change the return for both Property and Entity to use the overloaded Json method that allows you to bypass the new security check, like this:

return Json(validator.IsValid(Request["value"]), JsonRequestBehavior.AllowGet);

By: Glenn

Glenn — Tue, 27 Oct 2009 18:37:03 +0000

Thanks Adrian, I look forward to it! FYI, after my post I realized your attached solution was different than what your post covered.. Unfortunately it didn’t work when I used it in VS 2010 Beta 2 (I know, far from surprising, but wanted you to know).

FYI, here’s what I did to get it to compile in VS2010 Beta 2:

1. Used the solution converter here (to upgrade from MVC to MVC2): http://weblogs.asp.net/leftslipper/archive/2009/10/19/migrating-asp-net-mvc-1-0-applications-to-asp-net-mvc-2.aspx

2. Opened the solution in VS2010 beta 2, went thru the usual conversion; indicated I wanted to upgrade sites to ASP.NET 4.

3. Removed the System.ComponentModel.DataAnnotations DLL from /bin

4. Updated the reference for xVal to my local copy of 0.8 (same version as the project)

5. ValidationAttribute.TryValidate, referenced a few times in DataAnnotationsModelBinder, is no longer in the API; I updated to use ValidationAttribute.GetValidationResult (the rest of the code was self explanatory)

After all of this work, I was left in the same spot I was previously with VS2010 Beta 2- the remotevalidationrule is constructed on the client when the field is first asked to be validated, a response is sent to the server, the server responses, and then… nothing.. Nada. I even changed the controller’s response to simply return a JsonResult of false to bypass the logic, breakpoint shows that is happening, but nothing happens on the client. Note the other client-side rules fire just fine.

Oh well. Thus is the price of bleeding edge technology.