MVC3: Attribute for not mapping a property to a DB column - asp.net-mvc-3

I’m using ASP.NET MVC3. I have a model that has one property that I don’t want to store in the database. Is there an attribute that I can put on the property to achieve this? Thanks.

public class Person
{
[Key]
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
[NotMapped]
public string FullName { get; set; }
}
The attribute are in the namespace System.ComponentModel.DataAnnotations

Just to add more options... this is why I prefer to keep my domain model separate from my view model. My view model often has additional fields necessary for rendering the view which does not belong in the domain model. The design I typically use is described pretty well here.

Related

Is there a way to conditionally validate a model based on the http verb used?

I'm writing an API and have a very simple model
public class CategoryModel
{
public int ID { get; set; }
[Required]
[StringLength(30)]
public string Name { get; set; }
public string Description { get; set; }
}
I don't want to enforce that the ID property is required if the model is coming in via a post action, but I do if it's a put action. Are there any validation attributes that allow for this or do I need to create a separate model for post and put?
I'm just learning this so I could be doing it wrong altogether so a point in the right direction would be appreciated!
Thanks!
We can do by use fluentvalidation library or create customer attribute

Is there a way remove property using Data Annotation in Asp.net MVC3?

Public class UserMetdata
{
[Required]
[Display(Name="User ID")]
public int UserID { get; set; }
[Display(Name="User Name")]
public string UserName { get; set; }
}
I dont want to UserName to be shown in View. Its similar like creating not required Annotation. One solution is by deleting UserName form Class but i dont want that.
How can it be done using Data Annotation.
You could use ScaffoldColumnAttribute for that property
[ScaffoldColumn(false)]
public string UserName { get; set; }
This will work only when you let framework dynamically generate your views by calling #Html.DisplayForModel() or like, and you DO NOT have defined display template for that model at Views/Shared/DisplayTemplates or Views/ControllerName/DisplayTemplates. Otherwise, you should edit that display template and remove corresponding line from it

Custom validation in ASP.NET MVC

I have a Page object that contains a Metadata property like this
public class Page {
public int Id { get; set; }
public int ParentId { get; set; }
public Metadata Metadata { get; set; }
}
public class Metadata {
public string Slug { get; set; }
}
when I save my page I need to verify that no other page with the same parent has the same slug. I was thinking about using a validation attribute on the slug property but when I do that I'm not able to find the page object. What is the best approach of validating such things?
If you insist upon using data annotations validation attributes, you could get access to all of the properties by putting the attribute on the Page class rather than the Slug property.
However there is something better.

How to access an association in view from one POCO with several references to another

Sorry about the title; couldn't think of a better one.
Any way, I'm accessing an associated property in my view like so:
#Model.Company.CompanyName // No problems here...
The model is a viewmodel mapped to an EF POCO. The Model has several properties associated to the Company table. Only one of the properties in the model share the same name as the PK in the Company table. All the other properties reference the same table:
public class MyModelClass
{
public int Id { get; set; }
public int CompanyId { get; set; }
public int AnotherCompanyId { get; set; } // References CompanyId
public int AndAnotherCompanyId { get; set; } // References CompanyId
public Company Company { get; set; }
}
public class Company
{
public int CompanyId { get; set; }
public string CompanyName { get; set; }
public string Address { get; set; }
}
I'm obviously missing something here.
How can I get the names of the other companies in my Model?
Any help is greatly appreciated.
The model is a viewmodel mapped to an EF POCO
I think you are confusing the notion of a view model. A view model is a class that is specifically designed to meet the requirements of your view. So if in your view you need to display the company name and not the company id then your view model should directly contain a CompanyName property. Or a reference to another view model (CompanyViewModel) which contains the name directly. It is then the responsibility of your controller action to query your domain models (EF entities) and aggregate them into a single view model tat will contain all the necessary information that the view requires.
Here's how a typical view model might look like:
public class MyViewModel
{
public CompanyViewModel Company { get; set; }
public CompanyViewModel AnotherCompany { get; set; }
public CompanyViewModel AndAnotherCompany { get; set; }
}
public class CompanyViewModel
{
public string Name { get; set; }
}
Where the data comes from in this view model is not important. You could have the Company property populated from your EF stuff, the AnotherCompany property populated from a XML file and AndAnotherCompany from WCF.

Required attribute for complex objects

I have a class like this
public class PageReference {
[ScaffoldColumn(false)]
public string Id { get; set; }
public string Name { get; set; }
}
and in my model I use it like this
[Required]
public PageReference PageLink { get; set; }
the required attribute does not fire if I add it to the pagelink property, how can this be solved?
The validation attribute is evaluated by the model binder against the data supplied by the value provider (often posted form fields). If you're posting a form that does not include that field, the binder won't touch that property of the model and so won't evaluate the validation attributes.
I think there is no recursive validation support in asp.net mvc

Resources