April 4. 2008 23:37

This is very impressive, Matt.

Now what would be nice is if the validation rules came from the model. Using the example from your code, let's say you had a Person class which had a method named GetValidators that returned an array of ValidationRules. That method could look like this:

public List<ValidatedProperty> GetValidators()
{
return new List<ValidatedProperty>{

new ValidatedProperty("firstName", new List<ValidationRule>{
new RequiredFieldValidation(),
new RegexValidation( "[a-zA-Z]", "First Name can only contain letters" )
},

new ValidatedProperty( "age", new List<ValidationRule>{
new RequiredFieldValidation( "Age is Required." ),
new RegexValidation( "[0-9]*" ),
new RangeValidation<int>( 18, 35 )
}

};
}

Now it would be easy to pass the model into the view to construct the validation dynamically, like:

First Name: <%= Html.TextBox("firstName") %>
<%= Html.Validate( "firstName", Validations["firstName"] ) %>

The benefit of doing it like this is in the controller's Save() action, we could also reconstitute the validators from the model and double-check on the server side. Maybe something like:

public void Save()
{
Person person = new Person( Request.Form["firstName"] );
Binding.UpdateFrom( person, Request.Form );
if( Validator.IsValid( person.GetValidators() )
person.Save()
else
// throw an exception or whatever
}

What do you think? Sorry for the lack of formatting... =/

Troy Goode

April 7. 2008 17:40

Hey Matt - as a longtime user of your eWorld stuff it's nice to see you throw some love at MVC! Have some thoughts for you...

1) Agree with other points that you don't want to have to declare validation for "Last name can't be NULL" in every page that takes a last name (Registration, Ship To, Bill To, Contact, whatever). There's a lot that we know with the model already - in fact if you're a SubSonic user you know the lengths, nullability, datatypes... etc...
2) It might be interesting to creat a validation lib that works specifically with other frameworks. SubSonic is one of em . You could also do a custom thing for LinqToSql (I have some code... email me!)

That would rock

Rob Conery

April 7. 2008 18:59

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Wöchentliche Rundablage: ASP.NET MVC, Silverlight 2, .NET, RegEx, .NET, Icons, CSS, UI | Code-Inside Blog

code-inside.de

April 8. 2008 02:55

I agree with Troy. I think the Model is the correct place to put the validation. Consider something like an attribute style validation mechanism like the Application Validation Block. By doing this you allow all views to leverage the same validation. When the view is rendered, you could interrogate the model for the validation attributes and inject those into the view for the pieces of the model that are presented in a form.

Scott Prugh

April 8. 2008 13:32

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Links Today (2008-04-08)

mhinze.com

April 24. 2008 14:14

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47 ASP.NET MVC Resources to Rock Your Development - Craig Shoemaker

weblogs.asp.net

May 9. 2008 06:30

I m having problem using the MVC Contrib getting following error any assitance will be helpful for me

The type 'System.Web.Mvc.ComponentController' is defined in an assembly that is not referenced. You must add a reference to assembly 'System.Web.Mvc, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'

<%=Html.Form().ValidatorRegistrationScripts %>

Muhammad Taufiq Yusuf

May 23. 2008 23:09

css textboxt ınput (textfield) style - examples - -
www.css-lessons.ucoz.com/textbox-css-examples.htm

chester..