My project is in ASP.NET MVC 3. In my domain I have a model object defined by Entity Framework. In order to validate properties I simply extend the generated EF object and add a metadata class which contains all my validation attributes.
[MetadataType(typeof(ContactInformationMetaData))]
public partial class ContactInformation
{
}
public class ContactInformationMetaData
{
[Required]
public string FirstName { get; set; }
[Required]
public string LastName { get; set; }
public string Phone { get; set; }
[EmailValidator]
public string Email { get; set; }
}
This works great most of the time but now I have a more complex scenario. I don't want the Phone and Email properties to be required but I want ONE of them to be required. In other words, I want to require that either email or phone or both be set, but not none.
How would I perform complex validation like this? If I create a custom validation attribute where would I put it and how would that work?
Here is another question exactly like that (even the Phone and Email example is the same):
Model Validation / ASP.NET MVC 3 - Conditional Required Attribute
Check out FluentValidation:
http://fluentvalidation.codeplex.com/wikipage?title=mvc
you can easily create this type of custom validation, it's a pretty cool validation framework in general
Related
Suppose I have the following example Resource Model defined for API Create/Read/Update/Delete interactions involving the Customer types:
public class CustomerModel
{
public string Address { get; set; }
public int Id { get; set; }
[Required]
public string Name { get; set; }
[Url]
public Uri Website { get; set; }
public DateTimeOffset WhenCreated { get; set; }
public DateTimeOffset WhenUpdated { get; set; }
}
Id, WhenCreated, and WhenUpdated are metadata to be generated by the underlying data repository and as such, if the customer adds them to a request they should not be kept (Id for example, would be specified in the URL so no need to include in the request body). However, these values are still important to the client.
Is there a simple approach to ignoring these metadata attributes if sent in the client request? I would expect this in the form of an attribute but have not found anything promising for .NET Core 3.1.
The JsonIgnore attribute would make sense but it wouldn't serialize the values in responses either.
I could create a separate model only used by clients for requests but this seems redundant, especially because it will require new mapping profiles. However, if using something like Swashbuckle for API documentation this could be the best approach since the class documentation wouldn't represent those as valid properties for requests.
I could add some logic to remove those properties in the business logic layer but that would likely involve another request to the database to retrieve their original values so it isn't ideal.
Thank you!
I have a ViewModel which is used for a Wizard containing two separate ViewModels which are used to load partial views into the wizard. Depending on the option selected on Step1, I need to validate either Step2 or Step3. The viewmodels for Step2 and 3 have their own AbstractValidator which works great because it includes client side validation. The problem is that if I use ModelState.IsValid, one of the VMs always fails to validate because it's empty (that step was not filled out). Is there a way to skip validation for one of the viewmodels?
Say you have the following model:
public class PersonViewModel
{
[Required]
public string Email { get; set; }
[Required]
public string Password { get; set; }
[Required]
public string FullName { get; set; }
}
But you want to exclude FullName from the model validation because you are using the model also in a place where FullName is not filled in, you can do so in the following way:
ModelState.Remove("FullName");
Hope to help, my friend :))
The solution I eventually arrived at was surprisingly simple but I didn't spot it in the docs. You can call $('#somecontainer').valid() which will show validation messages for supported controls and also return true if all controls in the container are valid. It doesn't work for everything as rules like GreaterThan aren't supported client side.
I'm learning asp.net mvc and wonder when we need to use BindAttribute.
The first case (using Bind):
Model:
public class Book
{
public string Id { get; set; }
public string Name { get; set; }
public string Author { get; set; }
}
Controller:
public IActionResult Create([Bind(nameof(Book.Name), nameof(Book.Author))] Book model)
{
return Ok();
}
The book Id would be generated on server side. So, client side has nothing to do with it, every actions try to change/make the id is prevented.
The second case (not using Bind):
Model:
public class BookViewModel
{
public string Name { get; set; }
public string Author { get; set; }
}
Controller:
public IActionResult Create(BookViewModel model)
{
return Ok();
}
Because the second model doesn't contain Id property, we don't need to prevent from creating or changing.
I prefer the second. It's easy to manage model.
Is there a case we must use Bind attribute?
We use bind when we want that some properties of complex property are ignored when received on server. It could be for safety or other reasons.
When this action is executed the MVC model binder will use the request parameters to populate the user parameter's properties, as you may already know. However, the Bind attribute tells the model binder to only populate properties with names specified.
So in this case only the Username, FullName and Email properties will be populated. All others will be ignored.
See here for more details: http://ittecture.wordpress.com/2009/05/01/tip-of-the-day-199-asp-net-mvc-defining-model-binding-explicitly/
If you have situation when you only have to ignore one parametar from binding you could use Exclude property:
[Exclude]
public Entity Name {get; set;}
Bind is used to increase security and unauthorized data to be posted on server . In your model class , suppose you have content property also. if the content property is not needed in the future. Then it would be difficult for you to remove all the occurrences of that property. Here you can use bind property like this
[Bind(exclude="content")]
or you can bind only selected properties to be posted on server by including the properties like this
public ActionResult create([Bind(Include = "Name,Author")] Modelclass modelclass)
{
//Do something here
}
You can learn more about it here
Second approach is more suitable instead writing all the properties and bind them but there are some situations where you must bind user like you have a roles property or IsAdmin property in your model then you might not want that user somehow posts the IsAdmin or roles properties to the server . That's where you can use Bind attribute
I have a project utilizing ASP.NET MVC and Razor page layouts. The page in question will be a survey whose questions, datatypes, and answers have been configured by an admin user and retrieved from a database. For example:
public class ExampleViewModel
{
//the user define dquestion
public string Question1Text { get; set; }
//this is an enum with "Text","YesNo","DropDown"
public AnswerType Question1Type { get; set; }
//this would hold options for the drop down list
public string Question1Options { get; set; }
//the user input answer
public string Question1Answer { get; set; }
}
What I am not sure is how to structure the Razor view to create the appropriate type of form input field depending on the AnswerType. I seem to recall something about creating templates for the various DataType() annotations but I am not sure where to start looking at that and if that applies in this case?
You want to use Templated Helpers - Here is a good walkthrough - http://www.hanselman.com/blog/ASPNETMVCDisplayTemplateAndEditorTemplatesForEntityFrameworkDbGeographySpatialTypes.aspx
In the helper itself you can do stuff like:
#if (model.AnswerType is xxx)
{
<button> xxx </button> - or your html
}
etc
I'm working with ASP.NET MVC 4, but I on't think that matters for the purpose of this question.
I have a relatively complex model for my edit view. Like this:
public class Recipe_model
{
public string Name { get; set; }
public List<Recipe_Ingredient_model> Ingredients { get; set; }
}
where Ingredients is
public class Recipe_Ingredient_model
{
public int RecipeID { get; set; }
public int? UnitID { get; set; }
public double? Quantity { get; set; }
public Ingredient_model Ingredient { get; set; }
}
which itself contains the Ingredient model.
When I make a form for this, the built-in Html.EditorFor() doesn't work for anything past the properties of the Recipe_model, so I'm using partial views to display the editor for each of the sub-models.
That works fine as far the interface goes, but when I submit the form to the controller and try to bind to the Recipe_model automatically using
[HttpPost]
public ActionResult Edit(Recipe_model model)
{
return View(model);
}
it fails because the ids of the input elements in the partial views do not conform to the correct pattern (I think ParentModel_Property).
Short from hard-coding the ids in the partial view or binding manually from the FormCollection in the controller, is there some way to get the correct ids generated in the partial view so that the model will bind automatically on submit?
This is common problem. Instead of simple partials, use EditorTemplates (special folder for models) and binding will work automatically.
For example look at this question: Updating multiple items within same view
in addition to the answer given by #WebDeveloper
you can also try and create a custom model binder though a little more complex but will add to the ease of posting and binding form value to the objects in long run
have a look here http://patrickdesjardins.com/blog/asp-net-mvc-model-binding
you will have to manually take all the form values and bind them to the model once and then you will be able to use the #HtmlFrom methods on the razor to do anything and you will get all the value inside the objects inside the action methods as you like.