Question

With help from StackOverflow today, I have gotten my data layer constructed return data from my XML file to my Business Logic Layer. However, I can’t seem to get the data from my business objects layer. The values are all null. Sorry, to be such a newbie…. Thanks in advance.

Business logic layer:

public void getCustDetails(string customerId)
{                          
    DLGetCustomers obj = new DLGetCustomers();
    obj.getCustDetails(customerId);
    AccountDetails obj1 = new AccountDetails();
    FirstName = obj1.Fname;
    LastName = obj1.Lname;
    SSN = obj1.Ssn;
    Dob = Convert.ToDateTime(obj1.Dob);
    CustomerId = Convert.ToInt32(obj1.Custid);
    TimeSpan ts = DateTime.Now - Convert.ToDateTime(Dob);
    Age = ts.Days / 365;
}

Data access layer:

public class AccountDetails
{
    public string Fname { get; set; }
    public string Lname { get; set; }
    public string Ssn { get; set; }
    public string Dob { get; set; }
    public string Custid { get; set; }
} 

public IEnumerable<AccountDetails> getCustDetails(string customerId)
{
    //Pulls customer information for selected customer 
    var doc = XDocument.Load("Portfolio.xml");
    var custRecords = from account in doc.Descendants("acct")
                      let acct = account.Element("acct")
                      where (string)account.Attribute("custid").Value == customerId
                      select new AccountDetails
                      {
                          Fname = (string)account.Attribute("fname").Value,
                          Lname = (string)account.Attribute("lname").Value,
                          Ssn = (string)account.Attribute("ssn").Value,
                          Dob = (string)account.Attribute("dob").Value,
                          Custid = (string)account.Attribute("custid").Value
                      };                          

    return custRecords;
}

Answer 1

This line:

AccountDetails obj1 = new AccountDetails();

Simply sets obj1 to a new instance of AccountDetails which would be full of empty strings.

You probably need to change getCustDetails in your DAL to return an instance of AccountDetails instead of an IEnumerable of it, and set obj1 to that:

AccountDetails obj1 = obj.getCustDetails(customerId);

In your DAL:

public AccountDetails getCustDetails(string customerId)
{
    //Pulls customer information for selected customer 
    var doc = XDocument.Load("Portfolio.xml");
    var custRecords = from account in doc.Descendants("acct")
                      let acct = account.Element("acct")
                      where (string)account.Attribute("custid").Value == customerId
                      select new AccountDetails
                      {
                          Fname = (string)account.Attribute("fname").Value,
                          Lname = (string)account.Attribute("lname").Value,
                          Ssn = (string)account.Attribute("ssn").Value,
                          Dob = (string)account.Attribute("dob").Value,
                          Custid = (string)account.Attribute("custid").Value
                      };


    return custRecords.FirstOrDefault();
} 

Note that if your DAL can’t find an account with the specified customerId, it will return a null (which is the default value of a class). You will need to check the return value against null before using if you do not want a NullReferenceException to be thrown in such an eventuality.