I have a model called Organisation, on the organisation I have a remote validation attribute:
[Required(ErrorMessage = "The organisation name is required")]
[Remote("NameCheck", "Manage", "Organisations", ErrorMessage="That organisation already exists")]
public string Name { get; set; }
This checks that the name of the organisation someone is adding doesn't already exists. If it does then they get an error message saying so.
I'm using a strongly typed view to render the organisation "edit" view. Because someone is editing, I don't want that remote validation to run because of course the organisation will exist.
Is there any way to achieve this? Basically, turn off the remote validation in some way when editing an organisation and have it turned on when creating an organisation.
You could/SHOULD use different view models for the two views. So for example you will have CreateOrganizationViewModel and UpdateOrganizationViewModel. On the first view model the Name property will be decorated with the remote attribute whereas on the second view model it will not.
public class BaseOrganizationModel {
public int ID {get; set;}
}
public class UpdateOrganizationModel : BaseOrganizationModel {
[Required(ErrorMessage = "The organisation name is required")]
public string Name { get; set; }
}
public class InsertOrganizationModel : BaseOrganizationModel {
[Required(ErrorMessage = "The organisation name is required")]
[Remote("NameCheck", "Manage", "Organisations", ErrorMessage="That organisation already exists")]
public string Name { get; set; }
}
Related
No code to show. I just want to understand something. I already do some MVC code (I have a model, I ask Visual Studio to create Controller and View).
Each view has only "ONE MODEL" associated. So, with Razor, I can show data from this model. I play with my code and I understand it up to now.
BUT ...
On the same view, HOW we can work with another MODEL ?
For me, a model is simply a class with properties, etc. My database has an equivalent "data table" for each model. I can manipulate it with Entity Framework ... no problem. But, I need to use DATA from different model (different table) in the SAME VIEW and Visual Studio does not give me permission to use another MODEL in the view.
What is the strategy ? (or maybe I don't understand something ...)
Thank you.
The strategy is to build a view model, a model built to be displayed, and represents the data that you need to use.
Example :
You have these classes, classes who are a representation of your database :
public class FootballTeam{
public string Name{get;set;}
public string Logo{get;set;}
}
public class FootballGame{
public Datetime Date {get;set;}
public string Competition {get;set;}
}
public class Referee{
public string Name{get;set;}
public int Experience {get;set;}
}
To display information about a match game, you can create a view model for this, class who can references some classes of your business model if necessary :
public class GameViewModel{
[DisplayName("Home team")]
public FootballTeam HomeTeam{get;set;}
[DisplayName("Referee")]
public Referee Referee{get;set;}
[DisplayName("Visitor team")]
public FootballTeam VisitorTeam {get;set;}
[DisplayName("Comments")]
public List<string> RedactionComments{get;set;}
}
And create a view who will consume this GameViewModel.
In general, when you create a new MVC project, your have a folder named "ViewModels" in your presentation layer who contains some classes like this one.
This method allows to separate your business model to your presentation model, which are 2 completely different things.
There are very good answers here : What is ViewModel in MVC?
You can update your model type of your razor view to any type you want. It will work as long as you are passing that type from your action method.
Simply open up the razor view and change the line where it says what type the model is.
#model Customer
Now you need to make sure that you are passing a Customer object from your action
public ActionResult Create()
{
return View( new Customer());
}
Also when you create a view, You do not need to necessarily select the Model type in the Dialog box. You can keep that empty and add it to the razor view as needed ( as shown above)
If you want to bring data from 2 different table, Create a new view model which has properties needed for the view and use that as your view's model type.
You should use ViewModal to Create a ViewModal that will be combination of two modals properties as per our need
ViewModel contains the fields which are represented in the strongly-typed view. It is used to pass data from controller to strongly-typed view with Own Defined Modals
Understand how to use View Modal in MVC From Link Below -
Understand View Modal In MVC
CODE THAT DEMONSTRATE HOW TO USE VIEWMODALS IN MVC
Product.cs
public class Product
{
public Product() { Id = Guid.NewGuid(); }
public Guid Id { get; set; }
public string ProductName { get; set; }
public virtual ProductCategory ProductCategory { get; set; }
}
ProductCategory.cs
public class ProductCategory
{
public int Id { get; set; }
public string CategoryName { get; set; }
public virtual ICollection<Product> Products { get; set; }
}
ProductViewModel.cs
public class ProductViewModel
{
public Guid Id { get; set; }
[Required(ErrorMessage = "required")]
public string ProductName { get; set; }
public int SelectedValue { get; set; }
public virtual ProductCategory ProductCategory { get; set; }
[DisplayName("Product Category")]
public virtual ICollection<ProductCategory> ProductCategories { get; set; }
}
I have a model in MVC like that;
public class Employee
{
public int EmployeeId { get; set; }
[Required]
[EmailAddress]
[DisplayName("Email")]
[Remote("doesEmailExist", "Employee", HttpMethod = "POST", ErrorMessage = "Email already exists. Please enter a different Email.")]
public string Email { get; set; }
}
On create action, that is okey, it works great. But on edit action, program see email address already exist. And I cannot update my employee with the same email address. What can I do?
You could use the AdditionalFields property of RemoteAttribute to include EmployeeId in the validation. Then in your action method, if EmployeeId=null validation fails if a matching email is found, otherwise only check for matching emails where its a different EmployeeID
I have the following model:
public class Contact
{
public Contact()
{
Name = "Your Name";
Email = "Your Email";
Message = "Your Message";
}
[Required]
[StringLength(60,MinimumLength = 3)]
public string Name { get; set; }
[Required]
[DataType(DataType.EmailAddress)]
[RegularExpression(#"\b[A-Z0-9._%-]+#[A-Z0-9.-]+\.[A-Z]{2,4}\b")]
public string Email { get; set; }
[Required]
[StringLength(2200, MinimumLength = 10)]
[DataType(DataType.MultilineText)]
public string Message { get; set; }
}
For Message and Name, their default values (in the constructor) actually pass validation, obviously that is bad. I know I could check for this and throw an error in the Controller, but I'm trying to find a way to do these in the model (as I assume that is the correct place to do it).
I wouldn't do this at all server side. Use a textbox watermark ala one of the many methods for ex.
http://code.google.com/p/jquery-watermark/
Those look like hints, not default values. You should implement these with javascript, instead of setting them as input values.
using ASP.NET MVC, I have a Model, to which I'm attaching attributes so that I can get use the MVC Model bound validation, but to doesn't this break the rule of MVC, where you are putting items that belong to the View, into the Model? I hope I don't come of as trying to be smart, I am however curious as to other's opinions.
public class Payments
{
[DataType(DataType.Text)]
[DisplayFormat(NullDisplayText="")]
[Display(Name="Payment Id")]
[Required(ErrorMessage="Required")]
public int PaymentId { get; set; } //todo: make this into a dropdown
[DataType(DataType.Text)]
[Display(Name="Bill Name")]
[Required(ErrorMessage = "Required")]
public string PaymentName { get; set; }
[DataType(DataType.Date)]
[Display(Name="Date to Post Payment")]
[Required(ErrorMessage = "Required")]
public DateTime PaymentDate { get; set; }
[DataType(DataType.Currency)]
[Range(0, 922337203685477.5807)]
[Required(ErrorMessage = "Required")]
public double PaymentAmount { get; set; }
}
MSDN Reference 1
MSDN Reference 2
Yes. Thats why you should use ViewModels.
You can, but don't have to, put those validation attributes in your model.
But it's better to use a ViewModel:
public class PaymentsViewModel
{
[DataType(DataType.Text)]
[DisplayFormat(NullDisplayText="")]
[Display(Name="Payment Id")]
[Required(ErrorMessage="Required")]
public int PaymentId { get; set; } //todo: make this into a dropdown
[DataType(DataType.Text)]
[Display(Name="Bill Name")]
[Required(ErrorMessage = "Required")]
public string PaymentName { get; set; }
[DataType(DataType.Date)]
[Display(Name="Date to Post Payment")]
[Required(ErrorMessage = "Required")]
public DateTime PaymentDate { get; set; }
[DataType(DataType.Currency)]
[Range(0, 922337203685477.5807)]
[Required(ErrorMessage = "Required")]
public double PaymentAmount { get; set; }
}
And in your View, instead of:
#model YourProject.Models.Payments
you use:
#model YourProject.Models.PaymentsViewModel
for validation.
Does it violate MVC in the strict sense, yeah, probably. Are there times when there's no harm in violating that? Sure. However, there are mechanisms to help you out and keep the concerns separate.
You can use your persisted domain objects in the views and validate against them, but when your view starts getting complicated, ViewModels become a necessity. For dead simple domain models or view-only views (not edits/creates), I'll sometimes fudge a bit and send them into the view as part of a composite object:
class MyViewModel
{
public MyDomainModel DomainObj;
public int OtherViewInfo;
}
However, for create and edit scenarios, ViewModels are far better. They allow you total control over the data being sent to the view and from the view.
If you are using EF 4.1 and CodeFirst, then yes, you'll end up with some duplication of attributes and properties between the domain and the ViewModel. This is unavoidable but gives you the flexibility of doing different validations specific to the view.
I've found it useful to have one extra layer of protection in the controller when actually saving the domain object in case I missed some validation in the view:
public class MyController : Controller
{
[HttpPost]
public ActionResult Edit(int id, MyViewModel model)
{
try
{
...Do stuff, check ModelState.IsValid...
_context.SaveChanges()
}
catch (DbEntityValidationException dbEx)
{
// Catch any validation errors on the domain that weren't duplicated
// in the viewmodel
ModelState.AddModelError("Form", dbEx);
}
return View(model);
}
}
The next question to ask is how you map between the domain model and the ViewModel. There are a number of strategies and tools out there - AutoMapper and ValueInjecter (yes, spelled wrong). Personally, I've been using ValueInjecter although if you setup a mapping layer, you can try both. I've found that neither will work in 100% of cases, or at least I could figure out how to do what I needed, but a mapping service makes it easy to define custom left-to-right maps.
I'm having some troubles with validation on my application.
Let's say I've the following models:
public class Company
{
public int id { get; set; }
[Required]
public String Name { get; set; }
public String Location { get; set; }
public List<Contacts> Contacts { get; set; }
}
public class Contact
{
public int id { get; set; }
[Required]
public String Name { get; set; }
[DataType(DataType.EmailAddress)]
public String Email { get; set; }
public String Telephone { get; set; }
public String Mobile { get; set; }
}
Now in my company create view I've two buttons, one to add contacts to the company, and another one to create the new company.
I detected which button was used in my controller like this (both buttons are named "button"):
[HttpPost]
public ActionResult Create(String button, FormCollection collection)
{
if(button == "AddContact")
{
AddContact(collection);
}
else
{
CreateCompany(collection);
}
}
While it's being created the object that represents the company that it's being create is stored in the session (for example HttpContext.Session["company"] = company;)
Now the problem is that if, for example, I try to add a contact without first specifying the company name, i get a validation error because the company name is required, which shouldn't happen because the user might want to add the contacts before adding the company info. Or if I try to save the company, I also get a validation error, because usually when saving the "add contact" form is empty, which means that the contact name (which is required as well) was not specified.
What I want to know is that if it's possible to validate the contact properties only when the addContact button is used, and validate the company properties only when the createCompany button is pressed.
For now i only need to do this serve-side, but if anyone has a solution to do this client-side as well i would appreciate the help.
You could trigger your own validation on the individual objects using
Validator.TryValidateObject(Object, ValidationContext, ICollection)
You can provide conditional validation using the Entity Framework by overriding DbEntityValidationResult in the DbContext. When this validation occurs in the DbContext you can access other entities. When validating a contact you can check the company too. For example:
protected override DbEntityValidationResult ValidateEntity(DbEntityEntry entityEntry, IDictionary<object, object> items)
{
var result = base.ValidateEntity(entityEntry, items);
ValidateContact(result);
return result;
}
private void ValidateContact(DbEntityValidationResult result)
{
var contact= result.Entry.Entity as Contact;
if (contact!= null && contact.ContactId != 0)
{
// Add validation code here, such as:
if(!string.IsNullOrEmpty(contact.Company.Name){
result.ValidationErrors.Add(
new DbValidationError(
"Contact",
"Company name cannot be null or empty when validating contacts.")
);
}
}
}
See Julia Lerman's Programming Entity Framework: DbContext http://www.amazon.com/Programming-Entity-Framework-Julia-Lerman/dp/1449312969 for more details.