how to create custom validation in mvc ?

Question

hi frnds i went for the interview .interviewer asked me this qus how to create custom validation in mvc or your project ? my ans is - using data annonation with attribute so he not satisfied my ans . please provide the ans and give some example

Rahul Kaushik · Answer

Using Data annotation is good practice but what is meant with custom data validation is that we have to mention the data annotationa long overriding the predefined function of validations. Like the link given below is overriding the validation check function for the isnull https://stackoverflow.com/questions/16100300/asp-net-mvc-custom-validation-by-dataannotation

Anjali Khan · Answer

Dear frnds This is fine thanks for the update.here I want chechbox using custom validation

Hamid Khan · Answer

I think interviewer do not want to use data annotation in this scenario you need to add your own validation class and implement your logic under this class method: but if you think for data annotation : then go for details: ValidationAttribute class is included in DataAnnotations namespace. It helps you to validate model data received from user. It gives you many in built validation attributes like StringLength Required DataType for validating model. http://dotnetmentors.com/mvc/how-to-do-custom-validation-using-validationattribute-of-aspnet-mvc.aspx

Gautam Parmar · Answer

let's sayIn validation we want the end date to be today's date instead of anyhardcode value. To achieve this we would be use DateTime.Now.ToShortDateString() as shown below. [Range( typeof (DateTime) 01/01/2015  DateTime.Now.ToShortDateString())] [DisplayFormat(DataFormatString = {0:d}  ApplyFormatInEditMode = true )] public DateTime HireDate { get ; set ; } At this point if you compile you will get an error - An attribute argument must be a constant expression typeof expression or array creation expression of an attribute parameter type. To fix this we can create a custom DateRangeAttribute. Here is the code. Copy and paste the following code in DateRangeAttribute.cs class file. public class DateRangeAttribute : RangeAttribute { public DateRangeAttribute( string minimumValue) : base ( typeof (DateTime) minimumValue DateTime.Now.ToShortDateString()) { } } Finally decorate Joining Date property with our custom DateRangeAttribute as shown below. [DateRange( 01/01/2015 )] [DisplayFormat(DataFormatString = {0:d}  ApplyFormatInEditMode = true )] public DateTime Dateofjoining{ get ; set ; }

Shraddha Tripathi · Answer

System.ComponentModel.DataAnnotations namespace. is the correct answer but The ValidationSummary can be used to display all the error messages for all the fields. It can also be used to display custom error messages.