Is it possible to use `[Range]` annotation for dates?

something like   

    [Range(typeof(DateTime), DateTime.MinValue.ToString(), DateTime.Today.ToString())]


Data Annotation Ranges of Dates

I&#39;ve got a view model like this:

    public class SignUpViewModel
    {
        [Required(ErrorMessage = &quot;Bitte lesen und akzeptieren Sie die AGB.&quot;)]
        [DisplayName(&quot;Ich habe die AGB gelesen und akzeptiere diese.&quot;)]
        public bool AgreesWithTerms { get; set; }
    }

The view markup code:

    &lt;%= Html.CheckBoxFor(m =&gt; m.AgreesWithTerms) %&gt;
    &lt;%= Html.LabelFor(m =&gt; m.AgreesWithTerms)%&gt;

The result:

No validation is executed. That&#39;s okay so far because bool is a value type and never null. But even if I make AgreesWithTerms nullable it won&#39;t work because the compiler shouts 

&quot;Templates can be used only with field access, property access, single-dimension array index, or single-parameter custom indexer expressions.&quot;

So, what&#39;s the correct way to handle this?

How to handle Booleans/CheckBoxes in ASP.NET MVC 2 with DataAnnotations?

Can I automatically validate complex child objects when validating a parent object and include the results in the populated `ICollection&lt;ValidationResult&gt;`?

If I run the following code:

    using System;
    using System.Collections.Generic;
    using System.ComponentModel.DataAnnotations;
    
    namespace ConsoleApplication1
    {
        public class Person
        {
            [Required]
            public string Name { get; set; }
    
            public Address Address { get; set; }
        }
    
        public class Address
        {
            [Required]
            public string Street { get; set; }
    
            [Required]
            public string City { get; set; }
    
            [Required]
            public string State { get; set; }
        }
    
        class Program
        {
            static void Main(string[] args)
            {
                Person person = new Person
                {
                    Name = null,
                    Address = new Address
                    {
                        Street = &quot;123 Any St&quot;,
                        City = &quot;New York&quot;,
                        State = null
                    }
                };
    
                var validationContext = new ValidationContext(person, null, null);
                var validationResults = new List&lt;ValidationResult&gt;();
    
                var isValid = Validator.TryValidateObject(person, validationContext, validationResults);
    
                Console.WriteLine(isValid);
    
                validationResults.ForEach(r =&gt; Console.WriteLine(r.ErrorMessage));
    
                Console.ReadKey(true);
            }
        }
    }

I get the following output:
&gt; `False`  
&gt; `The Name field is required.`

But I was expecting something similar to:
&gt; `False`  
&gt; `The Name field is required.`  
&gt; `The State field is required.`

----

I offered a bounty for a better child object validation solution but didn&#39;t get any takers, ideally

 * validating child objects to an arbitrary depth
 * handling multiple errors per object
 * correctly identifying the validation errors on the child object fields.

I&#39;m still surprised the framework doesn&#39;t support this.

How can I tell the Data Annotations validator to also validate complex child properties?

I have the following MVC 5 Razor HTML helper:

    @Html.TextBoxFor(m =&gt; m.ShortName, 
      new { @class = &quot;form-control&quot;, @placeholder = &quot;short name&quot;})

I need this field to be required (i.e. have a red outline when user navigates out without putting a value inn). In a WebForms HTML 5 I could just say `&lt;input type=&quot;text&quot; required /&gt;` to have this effect.
What is the proper syntax to accomplish this in a Razor syntax?

How to add &quot;required&quot; attribute to mvc razor viewmodel text input editor

I&#39;m working with the Code First feature of Entity Framework and I&#39;m trying to figure out how I can specify the column data types that should be created when the database is auto-generated.

I have a simple model:

    public class Article
    {
        public int ArticleID { get; set; }

        public string Title { get; set; }
        public string Author { get; set; }
        public string Summary { get; set; }
        public string SummaryHtml { get; set; }
        public string Body { get; set; }
        public string BodyHtml { get; set; }
        public string Slug { get; set; }

        public DateTime Published { get; set; }
        public DateTime Updated { get; set; }

        public virtual ICollection&lt;Comment&gt; Comments { get; set; }
    }

When I run my application, a SQL CE 4.0 database is automatically created with the following schema:

![DB Schema][1]

So far, so good! However, the data I will be inserting into the `Body` and `BodyHtml` properties is routinely larger than the maximum allowed length for the `NVarChar` column type, so I want EF to generate `Text` columns for these properties.

However, I cannot seem to find a way to do this! After quite a bit of Googling and reading, I tried to specify the column type using `DataAnnotations`, from information found in [this answer][2]:

    using System.ComponentModel.DataAnnotations;

    ...

    [Column(TypeName = &quot;Text&quot;)]
    public string Body { get; set; }

This throws the following exception (when the database is deleted and the app is re-run):

    Schema specified is not valid. Errors: (12,6) : error 0040: The Type text is not qualified with a namespace or alias. Only PrimitiveTypes can be used without qualification.

But I have no idea what namespace or alias I should be specifying, and I couldn&#39;t find anything that would tell me.

I also tried changing the annotation as per [this reference][3]:

    using System.Data.Linq.Mapping;

    ...

    [Column(DbType = &quot;Text&quot;)]
    public string Body { get; set; }

In this case a database _is_ created, but the `Body` column is still an `NVarChar(4000)`, so it seems that annotation is ignored.

Can anyone help? This seems like it should be a fairly common requirement, yet my searching has been fruitless!


  [1]: http://i.stack.imgur.com/A4OI9.gif
  [2]: https://stackoverflow.com/questions/4829776/generate-money-type-fields-using-code-first-ef-ctp5/4833477#4833477
  [3]: http://msdn.microsoft.com/en-us/library/system.data.linq.mapping.columnattribute.dbtype.aspx

How do I specify that a property should generate a TEXT column rather than an nvarchar(4000)

I have a .Net MVC 5 application that is using Data Annotations, Entity-Framework Jquery 2.1.3 and Jquery UI 1.11.4. 

When I render an edit form with an input of type date using the UK format &quot;dd/MM/YYYY&quot;; the following error message appears when using Google Chrome:

&gt; The specified value &#39;10/10/2001&#39; does not conform to the required format, &#39;yyyy-MM-dd&#39;.  jquery-2.1.3.js:5317

**Model**

    public class MyModel
    {
        [Column(TypeName = &quot;date&quot;), DataType(DataType.Date), Display(Name = &quot;My date&quot;)]
        [DisplayFormat(DataFormatString = &quot;{0:dd/MM/yyyy}&quot;)]
        public string MyDate { get; set; }
    }

**Mark up**

    &lt;input class=&quot;text-box single-line&quot; data-val=&quot;true&quot; data-val-date=&quot;The field My date must be a date.&quot; id=&quot;MyDate&quot; name=&quot;MyDate&quot; type=&quot;date&quot; value=&quot;10/10/2001&quot; /&gt;

The value is set correctly in the input control but the date does not appear in the browser. I first thought this was an issue with jQuery as it is appearing the jQuery script file, but when testing in IE and Firefox everything is working fine.

I then assumed it was my regional setting in chrome as by default Chrome thinks everyone English is in America, I changed the regional setting to UK and still the same issue appears.

A simple fix would be to change the format in my model to universal but to UK users this is a little alien.

Is there a way to tell chrome that accept date formats in &quot;dd/MM/YYYY&quot;?

The specified value does not conform to the required format yyyy-MM-dd

I would like to specify that a decimal field for a price must be &gt;= 0 but I don&#39;t really want to impose a max value.

Here&#39;s what I have so far...I&#39;m not sure what the correct way to do this is.

    [Range(typeof(decimal), &quot;0&quot;, &quot;??&quot;] public decimal Price { get; set; }

How to specify a min but no max decimal using the range data annotation attribute?

What is difference between `DisplayName` attribute and `Display` attribute in ASP.NET MVC?

displayname attribute vs display attribute

I was wondering if it is possible to disable the Required validation attribute in certain controller actions. I am wondering this because on one of my edit forms I do not require the user to enter values for fields that they have already specified previously. However I then implement logic that when they enter a value it uses some special logic to update the model, such as hashing a value etc.

Any sugestions on how to get around this problem?

EDIT:&lt;br/&gt;
And yes client validation is a problem here to, as it will not allow them to submit the form without entering a value.

Disable Required validation attribute under certain circumstances

What are the operative differences between these two validation packages when used for ASP.NET MVC validatation? They seem to have similar objects, all the way to their object names. Is one related to another? What are their differences? In what way do these differences denote different use cases?

* [Fluent Validation][1] (3rd party solution)
* [Data annotations][2] (Microsoft &quot;baked-in&quot;)


  [1]: https://github.com/JeremySkinner/FluentValidation
  [2]: http://www.asp.net/mvc/tutorials/validation-with-the-data-annotation-validators-cs

Fluent Validation vs. Data Annotations

I am using Entity Framework 4.3 and using Code Fist.

I have a class 

    public class User
    {
       public int UserId{get;set;}
       public string UserName{get;set;}
    }

How do I tell Entity Framework that UserName has to be unique when creating database table?
I would prefer to use data anotations instead of configuration file if possible.


Entity Framework code first unique column

On my MVC3 project, I store score prediction for football/soccer/hockey/... sport game. So one of properties of my prediction class looks like this:

    [Range(0, 15, ErrorMessage = &quot;Can only be between 0 .. 15&quot;)]
    [StringLength(2, ErrorMessage = &quot;Max 2 digits&quot;)]
    [Remote(&quot;PredictionOK&quot;, &quot;Predict&quot;, ErrorMessage = &quot;Prediction can only be a number in range 0 .. 15&quot;)]
    public int? HomeTeamPrediction { get; set; }


Now, I need also change error message for a data type, `int` in my case. There is some default one used - &quot;The field HomeTeamPrediction must be a number.&quot;. Need to find a way how to change this error message. This validation message also seem to take prediction for Remote validation one.

I&#39;ve tried `[DataType]` attribute but this does not seem to be plain number in `system.componentmodel.dataannotations.datatype` enumeration.



Int or Number DataType for DataAnnotation validation attribute

I&#39;m trying to use DataAnnotations in my WPF project to specify a maximum length of strings, with the following:

    using System.ComponentModel.DataAnnotations;

However, I get the error

&gt; The type or namespace name &#39;DataAnnotations&#39; does not exist in the
&gt; namespace &#39;System.ComponentModel&#39; (are you missing an assembly
&gt; reference?)

I&#39;ve seen other examples where `DataAnnotations` *does* exist in this namespace. I&#39;m using C#4. Is there any reason why I can&#39;t use this? What can I do to fix it?

Why can&#39;t I reference System.ComponentModel.DataAnnotations?

I have this attribute in my view model:

    [DataType(DataType.DateTime)]
    public DateTime? StartDate { get; set; }

If I want to display the date, or populate a textbox with the date, I have these:

    &lt;%: Model.StartDate %&gt;

    &lt;%: Html.TextBoxFor(m =&gt; m.StartDate) %&gt;

Whenever the date is displayed, it&#39;s displayed like: **01/01/2011 12:00:00 AM**

But I&#39;d like to only display **01/01/2011**

Is there a way to apply a display format with data annotations? I don&#39;t want to have to go to every instance where I display a date, and add some code to format it.

Assign format of DateTime with data annotations?

I have a Model with 4 properties which are of type string. I know you can validate the length of a single property by using the StringLength annotation. However I want to validate the length of the 4 properties combined. 

What is the MVC way to do this with data annotation?

I&#39;m asking this because I&#39;m new to MVC and want to do it the correct way before making my own solution.

ASP.NET MVC: Custom Validation by DataAnnotation

Is there a way through data annotations to require that a boolean property be set to true?

    public class MyAwesomeObj{
        public bool ThisMustBeTrue{get;set;}
    }

MVC Model require true

I have a class like this:

    public class Document
    {
       public int DocumentType{get;set;}
       
       [Required]
       public string Name{get;set;}

       [Required]
       public string Name2{get;set;}
    }

Now if I put a `[Required]` data annotation on the `Name` and `Name2` properties, then everything is ok and if `Name` or `Name2` are empty, validation will throw an error.

**But I want `Name` field only to be required if `DocumentType` is equal to 1
and `Name2` only required if `DocumentType` is equal to 2 .**



    public class Document
    {
       public int DocumentType{get;set;}
       
       [Required(Expression&lt;Func&lt;object, bool&gt;&gt;)]
       public string Name{get;set;}

       [Required(Expression&lt;Func&lt;object, bool&gt;&gt;)]
       public string Name2{get;set;}
    }

but I know I can&#39;t, it causes an error. What should I do for this requirement?

Conditionally required property using data annotations

I am using DataAnnotations for my model validation i.e.

    [Required(ErrorMessage=&quot;Please enter a name&quot;)]
	public string Name { get; set; }

In my controller, I am checking the value of ModelState. This is correctly returning false for invalid model data posted from my view.

However, when executing the unit test of my controller action, ModelState always returns true:

	[TestMethod]
	public void Submitting_Empty_Shipping_Details_Displays_Default_View_With_Error()
	{
		// Arrange
		CartController controller = new CartController(null, null);
		Cart cart = new Cart();
		cart.AddItem(new Product(), 1);

		// Act
		var result = controller.CheckOut(cart, new ShippingDetails() { Name = &quot;&quot; });

		// Assert
		Assert.IsTrue(string.IsNullOrEmpty(result.ViewName));
		Assert.IsFalse(result.ViewData.ModelState.IsValid);
	}

Do I need to do anything extra to set up the model validation in my tests?

Unit Testing ASP.NET DataAnnotations validation

I thought this would be a quick search on google but maybe I&#39;m missing something. Is there a way, using Data Annotations, to set a ViewModel property to create a HiddenInput when the markup get rendered?

The only annotations I&#39;ve found were to hide the property from the view entirely, I still want the property rendered but as a hidden input.

Asp.Net Mvc Hidden Field from Data Annotations

This is happening when I try to create the entity using a Create style action in Asp.Net MVC 2.


The POCO has the following properties:

    public int Id {get;set;}

    [Required]
    public string Message {get; set}

On the creation of the entity, the Id is set automatically, so there is no need for it on the Create action.

The ModelState says that &quot;The Id field is required&quot;, but I haven&#39;t set that to be so. 
Is there something automatic going on here?

**EDIT - Reason Revealed**

The reason for the issue is answered by Brad Wilson via Paul Speranza in one of the comments below where he says (cheers Paul): 

&gt; You&#39;re providing a value for
&gt; ID, you just didn&#39;t know you were.
&gt; It&#39;s in the route data of the default
&gt; route (&quot;{controller}/{action}/{id}&quot;),
&gt; and its default value is the empty
&gt; string, which isn&#39;t valid for an int.
&gt; Use the [Bind] attribute on your
&gt; action parameter to exclude ID. My
&gt; default route was: new { controller =
&gt; &quot;Customer&quot;, action = &quot;Edit&quot;, id = &quot; &quot;
&gt; } // Parameter defaults

**EDIT - Update Model technique**

I actually changed the way I did this again by using TryUpdateModel and the exclude parameter array asscoiated with that. 

        [HttpPost]
        public ActionResult Add(Venue collection)
        {
            Venue venue = new Venue();
            if (TryUpdateModel(venue, null, null, new[] { &quot;Id&quot; }))
            {
                _service.Add(venue);
                return RedirectToAction(&quot;Index&quot;, &quot;Manage&quot;);
            }
            return View(collection);
        }


&quot;The Id field is required&quot; validation message on Create; Id not set to [Required]

In ASP.MVC 3, how do I specify the columns and rows for a multiline `EditorFor` (textarea)? I am using `[UIHint(&quot;MultilineText&quot;)]`, but can&#39;t find any documentation on how to add attributes for the text area.

Desired HTML:

     &lt;textarea cols=&quot;40&quot; rows=&quot;10&quot;&gt;&lt;/textarea&gt;


Relevant Part of my MVC 3 Model:

    [UIHint(&quot;MultilineText&quot;)]
    public string Description { get; set; }

Relevant Part of my Razor cshtml:

    &lt;div class=&quot;editor-field&quot;&gt;
        @Html.EditorFor(model =&gt; model.Description)
    &lt;/div&gt;

What I&#39;m getting in View Source:

     &lt;div class=&quot;editor-field&quot;&gt;
         &lt;textarea class=&quot;text-box multi-line&quot; id=&quot;Description&quot; name=&quot;Description&quot;&gt;&lt;/textarea&gt;
     &lt;/div&gt;

How do I set rows and columns?


How do I specify the columns and rows of a multiline Editor-For in ASP.MVC?

I have a viewmodel with an Id property

    [Required]
    public int Id { get; set; }

But I think this attribute is working only for string properties.

When no Id is set, Id has value 0 and the model is valid.

How can I enforce that if no value for a int property is set, the model will be invalid ?



Required attribute for an integer value

I have an object graph sprinkled with DataAnnotation attributes, where some properties of objects are classes which themselves have validation attributes, and so on.

In the following scenario:

    public class Employee
    {
        [Required]
        public string Name { get; set; }
    
        [Required]
        public Address Address { get; set; }
    }
    
    public class Address
    {
        [Required]
        public string Line1 { get; set; }
    
        public string Line2 { get; set; }
    
        [Required]
        public string Town { get; set; }
    
        [Required]
        public string PostalCode { get; set; }
    }

If I try to validate an `Employee`&#39;s `Address` with no value for `PostalCode`, then I would like (and expect) an exception, but I get none. Here&#39;s how I&#39;m doing it:

    var employee = new Employee
    {
        Name = &quot;Neil Barnwell&quot;,
        Address = new Address
        {
            Line1 = &quot;My Road&quot;,
            Town = &quot;My Town&quot;,
            PostalCode = &quot;&quot; // &lt;- INVALID!
        }
    };

    Validator.ValidateObject(employee, new ValidationContext(employee, null, null));

What other options do I have with `Validator` that would ensure all properties are validated *recursively*?


DataAnnotations: Recursively validating an entire object graph

I&#39;m running EF 4.2 CF and want to create indexes on certain columns in my POCO objects.

As an example lets say we have this employee class:

    public class Employee
    {
      public int EmployeeID { get; set; }
      public string EmployeeCode { get; set; }
      public string FirstName { get; set; }
      public string LastName { get; set; }
      public DateTime HireDate { get; set; }
    }

We often do searches for employees by their EmployeeCode and since there are a lot of employees it would be nice to have that indexed for performance reasons.

Can we do this with fluent api somehow? or perhaps data annotations?

I know it is possible to execute sql commands something like this:

    context.Database.ExecuteSqlCommand(&quot;CREATE INDEX IX_NAME ON ...&quot;);

I would very much like to avoid raw SQL like that.

i know this does not exist but looking for something along those lines:

    class EmployeeConfiguration : EntityTypeConfiguration&lt;Employee&gt;
        {
            internal EmployeeConfiguration()
            {
                this.HasIndex(e =&gt; e.EmployeeCode)
                    .HasIndex(e =&gt; e.FirstName)
                    .HasIndex(e =&gt; e.LastName);
            }
        }

or maybe using `System.ComponentModel.DataAnnotations` the POCO could look like this (again i know this does not exist):
    
    public class Employee
    {
      public int EmployeeID { get; set; }
      [Indexed]
      public string EmployeeCode { get; set; }
      [Indexed]
      public string FirstName { get; set; }
      [Indexed]
      public string LastName { get; set; }
      public DateTime HireDate { get; set; }
    }


Anyone have any ideas on how to do this, or if there are any plans to implement a way to do this, the code first way?

**UPDATE:** As mentioned in the answer by Robba, this feature is implemented in EF version 6.1

Entity Framework Code First Fluent Api: Adding Indexes to columns

I&#39;m using `System.ComponentModel.DataAnnotations` to provide validation for my Entity Framework 4.1 project.

For example:
    
    public class Player
    {
        [Required]
        [MaxLength(30)]
        [Display(Name = &quot;Player Name&quot;)]
        public string PlayerName { get; set; }

        [MaxLength(100)]
        [Display(Name = &quot;Player Description&quot;)]
        public string PlayerDescription{ get; set; }
    }

I need to retrieve the `Display.Name` annotation value to show it in a message such as *The chosen &quot;Player Name&quot; is Frank.*

=================================================================================

Another example of why I could need to retrieve annotations:

    var playerNameTextBox = new TextBox();
    playerNameTextBox.MaxLength = GetAnnotation(myPlayer.PlayerName, MaxLength);

How can I do that?

How to retrieve Data Annotations from code? (programmatically)

My User model has these data annotations to validate input fields:

    [Required(ErrorMessage = &quot;Username is required&quot;)]
    [StringLength(16, ErrorMessage = &quot;Must be between 3 and 16 characters&quot;, MinimumLength = 3)]
    public string Username { get; set; }
        
    [Required(ErrorMessage = &quot;Email is required&quot;]
    [StringLength(16, ErrorMessage = &quot;Must be between 5 and 50 characters&quot;, MinimumLength = 5)]
    [RegularExpression(&quot;^[a-zA-Z0-9_.-]+@[a-zA-Z0-9-]+.[a-zA-Z0-9-.]+$&quot;, ErrorMessage = &quot;Must be a valid email&quot;)]
    public string Email { get; set; }

    [Required(ErrorMessage = &quot;Password is required&quot;]
    [StringLength(255, ErrorMessage = &quot;Must be between 5 and 255 characters&quot;, MinimumLength = 5)]
    public string Password { get; set; }

    [Required(ErrorMessage = &quot;Confirm Password is required&quot;]
    [StringLength(255, ErrorMessage = &quot;Must be between 5 and 255 characters&quot;, MinimumLength = 5)]
    public string ConfirmPassword { get; set; }

However, I&#39;m having trouble working out how to make sure Confirm Password is the same as Password. As far as I know only these validation routines exist: `Required, StringLength, Range, RegularExpression`.

What can I do here? Thanks.

Data Annotation to validate confirm password

Wanting to create custom data annotation validation. Are there any useful guides / samples on how to create them?

Firstly:  
StringLength with minimum and maximum length. I&#39;m aware .NET 4 can do this, but want to do the same in .NET 3.5, if possible being able to define minimum length only (at least x chars), maximum length only (up to x chars), or both (between x and y chars).

Secondly:  
Validation using modulus arithmetic - if the number is a valid length, I wish to validate using the Modulus 11 algorithm (I have already implemented it in JavaScript, so I guess it would just be a simple porting?)

**Update:**  
Solved second problem, was just a case of copying over the JavaScript implementation and making a few tweaks, so don&#39;t need a solution for that.

All Data Annotations Solutions on Gang of Coders

Total of 27 Data Annotations Solutions