The document provides an overview of data annotation in ASP.NET MVC, detailing its attributes and their functionalities for validating input fields. It covers when and where to validate data, including examples of attributes like 'required', 'stringlength', and 'range' for better user input checks. Additionally, it highlights the implementation of validation logic and the necessary scripts for client-side validation.

1. Presented By:
Jyotasana Bharti

2.  Validation Scenario
 What is Data Annotation
 Data Annotation Attributes
 How to work with Data Annotation Attributes
 Example
 Summary
 References

3. What to
Validate
• Property
• Entity
• Domain
Operation
When to
Validate
• During data
input
• On
submitting
data
• After
submission
of data
Where to
Validate
• Servers only
• Both Server
and client
How do
we write
logic
• Attributes
• Add
required
code
• Custom
Validation
Class

4.  key aspect for developing web application.
 used to configure your model classes, which will
highlight the most commonly needed
configurations.
 provides instant user input checking facility at
client side and provides to asp developer, a wide
range of validator attributes. Data Annotation
makes the validating process easy and quick.
 can be used after adding following namespace:
System.ComponentModel.DataAnnotations using
System.ComponentModel;

5. System.ComponentModel.DataAnnotations in
cludes the following attributes that impacts
the nullability or size of the column.
 Required
 Key
 Timestamp
 ConcurrencyCheck
 MinLength
 MaxLength
 StringLength

6.  System.ComponentModel.DataAnnotations.
Schema namespace includes the following
attributes that impacts the schema of the
database.
 Table
 Column
 Index
 ForeignKey
 NotMapped
 InverseProperty

7.  Required
Specifies that Input field cannot be empty.
Example:
1. [Required(ErrorMessage = "Name is Required")]
2. public string Name { get; set; }
 DisplayName
Specifies the display name for a property.
Example:
1. [DisplayName("Enter Your Name: ")]
2. public string Name { get; set; }
 StringLength
Specifies minimum and maximum length for a property.
Example:
1. [StringLength(50, MinimumLength = 3)]
2. public string Name { get; set; }
 Range
Specifies a range of numeric value.
Example:
1. [Range(1,120, ErrorMessage ="Age must be between 1-120 in years.")]
2. public int Age { get; set; }

8.  Bind
Include or Exclude value when adding form values to model properties.
Example:
[Bind(Exclude = "Id")]
 MaxLength
Specifies maximum length of string.
Example:
1. [MaxLength(50)]
2. public string Name { get; set; }
 Phone
Specifies that an input field value is well-formed phone number using Regular
Expression.
Example:
1. [DataType(DataType.PhoneNumber)]
2. [RegularExpression(@"^(?([0-9]{2})[-. ]?([0-9]{4})[-. ]?(
[0-9]{3})[-. ]?([0-9]{3})$", ErrorMessage = "Not a valid P
hone number")]
3. public string Name { get; set; }

9.  For creating model, StudentModel.cs

10. Then create a form in index.cshtml page.
Next add HomeController.cs with the following code:
Once we have define validation to the model by using data
annotations, these are automatically used by Html Helpers in views.
For client side validation to work, please ensure that below two
<SCRIPT> tag references are in the view.
Validate Model

11. <script src="@Url.Content("~/Scripts/jquery.validate.min.js")"
type="text/javascript"></script> <script
src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.min.js")"
type="text/javascript"></script>
When no data is entered then it will look like as:

12. After entering wrong data it looks like as
follows:

13. How to use Data Annotation for validating
input field in ASP.NET MVC 5 has been
explained with example.
Different Data Annotation Attributes are
explored.

14.  https://www.tutorialspoint.com/asp.net_mv
c/asp.net_mvc_data_annotations.htm
 https://www.slideshare.net/EyalV/aspnet-
mvc-30-validation
 https://www.dotnettricks.com/learn/mvc/m
vc-data-annotations-for-model-validation