data-annotations

I have a few questions regarding custom model binding, model state, and data annotations. 1) Is it redundant to do validation in the custom model binder if I have data annotations on my model, because that's what I thought the point of data annotations were. 2) Why is my controller treating the model state as valid even when it's not, mainly I make the Name property null or too short. 3) Is it ok to think of custom model binders as constructor methods, because that's what they remind me of. First here is my model. public class Projects { [Key] [Required] public Guid ProjectGuid { get; set; }

We manage several ASP.NET MVC client web sites, which all use a data annotation like the following to validate customer email addresses (I haven't included the regex here, for readability): [Required(ErrorMessage="Email is required")] [RegularExpression(@"MYREGEX", ErrorMessage = "Email address is not valid")] public string Email { get; set; } What I would like to do is to centralise this regular expression, so that if we make a change to it, all of the sites immediately pick it up and we don't have to manually change it in each one. The problem is that the regex argument of the data

Lets say I have a StartDate and an EndDate and I wnt to check if the EndDate is not more then 3 months apart from the Start Date public class DateCompare : ValidationAttribute { public String StartDate { get; set; } public String EndDate { get; set; } //Constructor to take in the property names that are supposed to be checked public DateCompare(String startDate, String endDate) { StartDate = startDate; EndDate = endDate; } public override bool IsValid(object value) { var str = value.ToString(); if (string.IsNullOrEmpty(str)) return true; DateTime theEndDate = DateTime.ParseExact(EndDate, "yyyy

ViewModel: public class MyViewModel { [Required, StringLength(50)] public String SomeProperty { ... } } XAML: <TextBox Text="{Binding SomeProperty}" MaxLength="50" /> Is there any way to avoid setting the MaxLength of the TextBox to match up my ViewModel (which could change since it is in a different assembly) and have it automatically set the max length based on the StringLength requirement? I used a Behavior to connect the TextBox to its bound property's validation attribute (if any). The behavior looks like this: /// <summary> /// Set the maximum length of a TextBox based on any

I'm trying to get server-side validation of an Entity Framework String Property to work. Other server-side validation such as data type validation and required dateTime and numeric EF properties are working. This in VS 2010, .Net 4.0, MVC2 + Cloud, ADO.Net Entity Framework. The String Property I am having issues with is mapped to a SQL 2008, Varchar(50) non-nullable column. When I try to post to my Create action with an empty string for this Property, I get the follwing error. Exception Details: System.Data.ConstraintException: This property cannot be set to a null value. When I post to the