I am working on an mvc3 application and having some problems with getting validation to work as I want.
The application is using buddy classes for the models. (This is something I haven't used in the past and I am a little confused why they are used...anyway)
I want to add required fields to ensure data been submitted is correct. I have tried adding the required field to the buddy class.
When I submit the form no client-side validation takes place and the debugger steps into the entity frameworks generated code. Here is complains that the fields that contain null values are causing are invalid. If I step through all of those it finally gets to the controller where my if (ModelState.IsValid) is showing false.
I have client-side validation switched on.
Am I meant to be applying the data validation at the buddy class level or at the view model?
One other question is why use buddy classes? to me they seem to over complicate things.
Updated added an example of the buddy class
[MetadataType(typeof (CustomerMetaData))]
public partial class Customer
{
public string Priorty
{
get
{
var desc = (Priority) Priority;
return desc.ToString().Replace('_', ' ');
}
}
internal class CustomerMetaData
{
[Required]
[DisplayName("Priorty")]
public string Priorty { get; set; }
Buddy classes are metadata classes to put data annotation attributes when you are not in control of the original class i.e. can't edit it. Typical situation is when the class is generated by an ORM like Entity Framework.
//Can't edit this class
public partial class YourClass{
public string SomeField {get; set;}
}
//Add a partial class
[MetadataType(typeof(YourClassMetadata))]
public partial class YourClass{
}
//And a metadata class
public class YourClassMetadata
{
[Required(ErrorMessage = "Some Field is required")]
public string SomeField {get; set;}
}
are you sure that you have [MetadataType(typeof(YourClassMetadata))]?
More about buddy classes here and here
You would typically use a buddy class when it isn't possible to add meta data to an entity class such as when a model is automatically generated by an ORM tool. In this case any meta data you had applied would be lost.
Therefore, your original (automatically generated) class would be defined as a partial class:
public partial class Customer
{
public string Priority { get; set; }
}
And then you would generate your buddy classes to add the meta data.
[MetadataType(typeof(CustomerMetaData))]
public partial class Customer
{
}
internal class CustomerMetaData
{
[Required]
public string Priority { get; set; }
}
You would then pass the Customer class to the view where the Priority would be set.
In your case i'm not sure if you only have one partial class or two (as the other is not shown but please provide if there is). I'm interested to know how you obtain the priority information from the customer as i'm wondering if this is an issue with how you use ModelState.IsValid? The reason I ask is that no set accessor is declared on the Priority property so i'm wondering how this is set from the view in order to report that it is not valid?
You would also use a buddy class when it isn't possible to add meta data to an entity class such as when a model is automatically generated by an WCF Data Contract.
Related
I am developing MVC application in which , I am trying to create the partial class of class generated by MVC application lets say Location class.
Now I want to create the partial class of Location class in new class file.
The below class code is auto genrated by MVC of Location code.
namespace CRM
{
public partial class Location
{
public int Id { get; set; }
public string Name { get; set; }
public string Remark { get; set; }
}
}
I have added new class file which contain the partial class of above file
namespace CRMEntities.Partial_Class
{
public interface ILocation
{
[StringLength(50, ErrorMessage = "Region can accept maximum 50 characters.")]
string Region { get; set; }
[Key]
int Id { get; set; }
[Required]
string Name { get; set; }
string Remark { get; set; }
}
public partial class Location : ILocation
{
}
}
Its giving the below error...
CRMEntities.Partial_Class.Location' does not implement interface member 'CRMEntities.Partial_Class.ILocation.Name
First, you don't need to do this, what I understand is you are trying to do validation right? Think about, the object generated by EF is not ViewModel, they are domain model. Data annotation should be in View Model, not domain model.
Most of cases, often mis-use is to use domain model as view model, but it is not correct much. Because sometime, view models need more than one domain model to provide data for your UI.
So for separation of concerns, you need to define your View Model different with domain model.
Example: you have Location class, you need to add LocationViewModel class and put data annotation in here.
You can map manually or use AutoMapper for mapping bettween View Model and Domain Model.
Another solution is you can use Fluent Validation, with this way, needless to have more partial class just for validation.
You don't show the definition of ILocation in your question, but the error says that the Location.Name property is declared differently than the ILocation.Name member.
Edit: Your two partial classes appear to be in two different namespaces, hence they are actually two entirely different classes, not two parts of the same class. That would explain the compiler error.
Having said that, I do agree with the other answer (+1!) that you should do your UI validation on a view model instead.
If I add [Required] in my entity class then unobtrusive validation works fine.
[Required] is not added where I generate my entity class using database first(*.edmx).
If I manually add [Required] in my entity property, something like
[Required]
public int {get;set;}
[Required] will delete when I update my edmx.
So my question is how can I perform client side validation if I use database first in EF.
Create a partial class for your entity and use the MetadataType attribute. See example below:
[MetadataType(typeof(MyEntity.Metadata))]
public partial class MyEntity
{
private sealed class Metadata
{
[Required(ErrorMessage = "* required")]
public string MyRequiredField { get; set; }
}
// Add other similar properties here...
}
This class will be unaffected by changes in the designer generated code.
This is a question for ado.net team. I suppose that when you use database first EF your domain model inherits constraints of database because database design is master for your application logic.
I used LINQ to SQL to generate a dbml file which contains the database model for my database table. I want to use UIHint to let MVC present some fields as DropDownLists or Checkboxes in edit mode. But if I change the file, it will be lost if it's been regenerated. How should I solve that issue? I'm quite new to MVC and still learning. I've set up a controller with views for all CRUD elements, but now I'm finetuning and I'm running into this problem.
Since Linq-to-SQL auto-generates partial classes, you'll need to create a partial 'buddy class' where you will add your Data Annotations. Your buddy class mirrors portions of the auto-generated class that you need to modify. You tie them together with [MetadataType(typeof(BuddyClassName))] The partial buddy class and the auto-generated partial class will be merged together when you compile your project.
In an example given that:
Your namespace is "Project.Models"
Your Linq-To-Sql class is called "Products"
using System.ComponentModel.DataAnnotations;
namespace Project.Models
{
[MetadataType(typeof(ProductsMeta))]
public partial class Products
{
// You can extend the products class here if desired.
public class ProductsMeta
{
// This is a Linq-to-Sql Buddy Class
// In here you can add DataAnnotations to the auto-generated partial class
[Key]
public int ProductKey { get; set; }
[Display (Name = "Product Name")]
[Required(ErrorMessage = "Product Name Required")]
[StringLength(255, ErrorMessage = "Must be under 255 characters")]
public string ProductName { get; set; }
[UIHint("MultilineText")]
public string Description { get; set; }
}
}
}
These articles were very helpful:
ScottGu: ASP.NET MVC 2: Model Validation
How to: Validate Model Data Using DataAnnotations Attributes
Validating with Data Annotation Validators
If you are going to use the entities directly you should create a partial class and add your annotations there. This way when the model is regenerated you will not lose your annotations.
I have a Subsonic3 Active Record generated partial User class which I've extended on with some methods in a separate partial class.
I would like to know if it is possible to add Data Annotations to the member properties on one partial class where it's declared on the other Subsonic Generated one I tried this.
public partial class User
{
[DataType(DataType.EmailAddress, ErrorMessage = "Please enter an email address")]
public string Email { get; set; }
...
}
That examples gives the "Member is already defined" error.
I think I might have seen an example a while ago of what I'm trying to do with Dynamic Data and Linq2Sql.
What you will need to do is create a 'buddy class' and apply the Data Annotations to that class:
[MetadataType(typeof(UserValidation))]
public partial class User
{
...
}
public class UserValidation
{
[DataType(DataType.EmailAddress, ErrorMessage = "Please enter an email address")]
public string Email { get; set; }
}
You should create a buddy class as explained here by Scott Guthrie
http://weblogs.asp.net/scottgu/archive/2010/01/15/asp-net-mvc-2-model-validation.aspx
This won't directly answer your question, but I had the same problem, and rather than using DataAnnotations, I've been using the FluentValidation framework {0} with great success so far. It works nicely because it provides much of the same functionality, but doesn't apply validation by using attributes on members of the class. Validation happens in a completely separate class that acts on the class being validated (i.e. UserValidator).
{0}: http://fluentvalidation.codeplex.com/
Castle Validator uses attributes to specify validation rules. How can you hook these up with Subsonic's generated classes (or any classes where you can't define the attributes on)? Is there a way to programatically specify validation rules without using the attribute method?
I think the best way to do that is using MetadataType.
It's a DataAnnotations that let's your class have like a pair or something like that. I don't know how to explain it better so, let's for the samples:
You first need to add this directive to your code:
using System.ComponentModel.DataAnnotations;
Them you should create the partial class of you generated class with an attribute specifying that this class has an MetadataType:
[MetadataType(typeof(UserMetadata))]
public partial class User
{
}
Then you create your metadata class with your castle validation:
public class UserMetadata
{
[ValidateNonEmpty]
[ValidateLength(6, 24)]
public string Username { get; set; }
[ValidateNonEmpty]
[ValidateLength(6, 100)]
[ValidateEmail]
public string Email { get; set; }
[ValidateNonEmpty]
[ValidateLength(6, 24)]
public string Password { get; set; }
}
There are a few ways to do this - attributes is the lowest friction option, but obviously doesn't deal well with generated code or validation of multiple properties better expressed in code.
Take a look at the following link for some indications on how to do this blog post: Castle Validator Enhancements
If you have a look at the castle source code these are some good starting points:
IValidationContributor interface
DefaultValidationPerformer class