.net MVC Validation with Data Annotation

With MVC you can validate data in the UI and before sending to the database auto-magically if you add Data Annaotation Validators to your model classes. Here are some of the more commonly used validators and samples on how to use them.

Add using System.ComponentModel.DataAnnotations; to your model.

[Required] – States the field is required

sample :
[Required( AllowEmptyStrings=false,ErrorMessage=”You must eneter a name”)]
public string Name { get; set; }

[StringLength] – Used to set min and max string length.

[StringLength (20,MinimumLength=5,ErrorMessage=”Name must be between 5 and 20 characters”)]

[MaxLength] – Max length of a string

[MaxLength(20,ErrorMessage=”Name must be less than 20 Characters”);
public string Name { get; set; }

[MinLength] – minimum length of a string

[MinLength (5,ErrorMessage=”Name must be more than 5 characters”)]
public string Name { get; set; }

[Range] – States the value of a number must be between x and y.

[Range (1,99,ErrorMessage=”Age must be between 1 and 99″)]
public int age {get;set;}

[RegularExpression] – Used to validate the format of a string

[RegularExpression(“[a-z0-9!#$%&’*+/=?^_`{|}~-]+(?:\\.[a-z0-9!#$%&’*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?”, ErrorMessage=”Invalid Email Address”)]
public string Email { get; set; }

[PropertiesMustMatch] – Class level attribute used to validate something like Password1 = Password2.

[PropertiesMustMatch(“Password”, “ConfirmPassword”, ErrorMessage = “The password and confirmation password do not match.”)]
public class user {

public string name {get;set;}

public string Password {get;set;}

public string ConfirmPassword {get;set;}


Rich Text Editing with CKEditor, MVC 3 and the Razor Engine

I was creating a model /view for editing large chunks of text on my website with MVC and the Razor engine. I created everything following Sott Gu’s tutorial on how to build a music store. When all was said and done I had a 50 character wide single line textbox for editing a large html block and thought ok this isn’t I deal.  Here are the steps I took to get a rich text editor in there.

Most of this came from this post on code project but it’s a bit outdated and doesn’t have everything.

The FCK Editor became the CK Editor, I guess they opted to drop the F over adding a U.

Step 1  : Change to Text Area

You should  have something like this in your Create and Edit Views

@Html.EditorFor(model => model.Text)

Lets change that to :

@Html.TextAreaFor(model => model.Text, new { @class = “adminRichText” })

Step 2 : Widen the text area

In your Site.Css file add the folowing to widen the text area :


Step 3 : Add the CK Editor (formerly FCK Editor) to your project

a. Download here

b. Create a ‘Javascript’ folder under ‘Content’ in your website.

c. Extract to /Javascript/Content.

Step 4 : Include the scripts in your View

Below the validation scripts add

<script type=”text/javascript” src=”@Url.Content(“~/content/javascript/ckeditor/ckeditor.js”)”></script>

<script type=”text/javascript” src=”@Url.Content(“~/content/javascript/ckeditor/adapters/jquery.js”)”></script>

Step 5 : Turn the text area into a Rich Text Box

At bottom of view after controls are initialized add:

<script language=”javascript” type=”text/javascript”>

Step 6 : Enable Post Back of Rich Text for your Edit and Create Methods in your controller class

[HttpPost, ValidateInput(false)]
public ActionResult Create(AreaText areaText)

[HttpPost, ValidateInput(false)]
public ActionResult Edit(string id, FormCollection collection)

Step 7: Use Html.Raw to display the data

On your index view update the output area to decode the html.




ckEditor in mvc

ckEditor in mvc

Note : There are some good suggestions in the comments on ways to continue using validation :

Option 1 from Micheal.
“In your CKEditor config file add the following line:
config.htmlEncodeOutput = true;”

Option 2 from Blair.
“I was able to get this to work without having to turn off validation by putting in
[AllowHtml] in the property definition”

Consuming JSON with Dynamics and C# 4.0

I don’t know if there’s a more standard way of doing this but I found this article that has some helper classes for consuming Json in C# : http://www.drowningintechnicaldebt.com/ShawnWeisfeld/archive/2010/08/22/using-c-4.0-and-dynamic-to-parse-json.aspx.

You can then steal consume data off of peoples Ajax applications. Course there’s no contract there and it’s not really built for public consumption so if they change the format on you it’d be kind of funny. I have seen some api’s spit out json but they tend to have a query string parameter to receive the info in xml.

That being said, it works. I don’t know if there’s a more standard way of consuming JSON in C#. If there is a more standard way I missed that link.