Question

I have a view model

 public class PersonsViewmodel
    {
     public string FirstName { get; set; }// from DB
     public string LastName { get; set; }// from DB
     public string FullName { get; set; } // this should be a custom value
 }

The linq query

  var per = from p in db.Persons  where p.Active==0          
                     select new PersonsViewmodel
                     { FirstName =p.FirstName ,LastName =p.LastName ,
FullName =Reg(p.FirstName)
};

public static string Reg(string str)
                 {
                    return str = Regex.Replace(str, "[^a-zA-Z0-9]+", "-", RegexOptions.Compiled);
                 }

This throws a error

LINQ to Entities does not recognize the method ‘System.String
reg(System.String)’ method, and this method cannot be translated into
a store expression.

Is there a better way to call this Reg function in the model itself instead of calling in the linq query or should i call the function after the linq query?

Right now I am doing this operation in the View like

@{
var FullName = Regex.Replace(model.FirstName, "[^a-zA-Z0-9]+", "-");
}

and using the variable FullName to render.

Answer 1

Isn’t that a job for the view model?

public class PersonsViewmodel
{
    public string FirstName { get; set; }// from DB
    public string LastName { get; set; }// from DB
    public string FullName 
    { 
        get 
        { 
            return Regex.Replace(FirstName, "[^a-zA-Z0-9]+", "-", RegexOptions.Compiled); 
        }
    }
}