How to add custom validators in mvc4?
Create MVC project
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Select basic project
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Add Sample controller
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Add “Customer.cs” file to use as model while creating View.
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Add View in Sample Controller
Select strongly type view and select customer.cs
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Now Add Required Attribute on property of customer - above Name
Required inbuilt property for validation after adding using System.ComponentModel.DataAnnotations;
This required attribute make that textbox mandatory.
public class Customer
{
[Required]
public string Name { get; set; }
}We have to add custom validator like need some special word in textbox value.
Then just write [RequiredSpecialWord] and press ctrl + . and create class
Now check “RequiredSpecialWord.cs” in model folder. It inherited from ValidationAttribute class
Now override method isValid in RequiredSpecialWord.cs
Check below code
public class RequiredSpecialWord:ValidationAttribute
{
private string _word;
public RequiredSpecialWord(string word)
{
_word = word;
}
protected override ValidationResult IsValid(object value, ValidationContext validationContext)
{
if (Convert.ToString(value).Contains(_word))
{
return ValidationResult.Success;
}
else
{
return new ValidationResult(_word +" not included");
}
}
}
Check ModelState.IsValid property in controller.
public ActionResult contact(Customer cust)
{
if (!ModelState.IsValid)
{
return View("index");
}
return View();
}
ModelState.IsValid checks that your validation are valid or not.
Now just run your project and add sample/Index in your browser url after localhost.
And see output
After clicking submit button. You will get below result. Because we added Required validator and we have not put anything in textbox.
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Now I entered text as aaaa and pressed submit, then I got below result
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That is Ram not included. Ram is normal word it can be Rob, Dan anything.
To change Ram word use below code in customer.cs
[RequiredSpecialWord("Ram")]
public string Name { get; set; }
Find attached source code, if you get any issue feel free to contact me.