I have a problem with MVC3 model validation and DataAnnotations
I have the following classes:
public class A
{
public C SomeProperty {get;set;}
}
public class B
{
[Required]
public C SomeProperty {get;set;}
}
public class C
{
[Required]
public string SomeSubProperty {get;set;}
}
This is because C can be required for some objects and not required for others, but if C is required i want SomeSubProperty to also be required.
However when i call ModelState.IsValid in my controller it will return false when using both A and B as models if SomeSubProperty is not set. Is there any way i can produce this behaviour?
I don't normally mix "Domain Model" with "View Model".
Domain model reflects business relationship and it can be very complex whereas view model suppose to be very flat and doesn't have deep levels of dependencies so that you are able to use Annotations.
Take a look at AutoMapper. Define each ViewModel with its specific requirements, and map it to the domain model for processing once validation has succeeded.
Related
I have a model that contains an interface based property, which the concrete implementation being discoverable via another property of the model.
public class SubscriptionViewModel
{
public Guid Id { get; set; }
...
public SubscriptionTypeEnum SubscriptionType { get; set; } // <- Determines the concrete class
public ISubscriptionCriteria SubscriptionCriteria { get; set; } //<- Property based on interface class
...
}
When the interface based property is present the model in the controller comes through as null. If removed, everything binds as expected.
[HttpPost("api/[controller]/[action]")]
public async Task Post([FromBody]SubscriptionViewModel model)
{
...
}
This will be because the controller doesn't know which solid implementation to use for the interface.
Any ideas how I can solve this? It looks like this might be achievable using a custom IModelBinderProvider or BindingBehaviorAttribute?
I guess I could have a SuperSubscriptionCriteria implementation that contains all possible properties used by concrete implementations of ISubscriptionCriteria and then rely on AutoMapper to convert them to the real implementations. But this seems like a hack and would require on-going maintenance as new ISubscriptionCriteria implementations are added.
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.
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.
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.
For example, in an IDE application, say for C#, there are 2 views ClassView and TextView.
In ClassView we need to display the Class information in a hierarchical manner, where as in TextView the code for that Class is shown.
The ClassView needs to query for classes, methods, properties, fields, etc. whereas the Text View queries lines in the code.
Both the views are editable. Change in one view should be reflected in the other view too.
So Class View requires one model and Text View requires another but the underlying data is the same.
Is there a design pattern to solve such a problem?
Thanks in advance.
Certainly an MVC model can be hierarchical. If your data is all contained in a single file, maybe you don't really need multiple models for your application? How about:
namespace MyNamespace
{
public class CodeFile
{
/// <summary>
/// A list of contained classes for the Class view
/// </summary>
public List<CodeClass> Classes { get; set; }
public CodeFile()
{
Classes = new List<CodeClass>();
}
public string ToString()
{
// send output to Text view
}
}
public class CodeClass
{
public string ClassName {get; set;}
public List<CodeProperty> Properties {get; set;}
public List<CodeMethod> Methods {get;set;}
public CodeClass(string className)
{
ClassName = className;
Properties = new List<CodeProperty>();
Methods = new List<CodeMethod>();
}
}
public class CodeMethod
{
public string MethodName { get; set; }
}
public class CodeProperty
{
public string PropertyName
}
}
Model View Controller :)
The mistake in your question is that your data is actually mapped on your model.
You can have 2 views (classview and textview) and they both works with one single common model. Controller can update one view when another one changes the model.
You tagged it yourself with MVC... The underlying data is the model, the Class View and Text View act as views/controllers. The model sends out events to its views, to make sure that changes in one view are reflected in the other.
There's nothing in MVC architecture to prevent writing multiple model hierarchies which interact with the same underlying data store.
You would just have Controllers/Views which interact with Model A, and different Controllers/Views which interact with Model B.