Christopher Latham\'s Portfolio

1. .Net Portfolio
Christopher Latham
lathamcl@gmail.com
(360)223-8745

2. Table of Contents
• SetFocus Library System Overview
• Windows Sample Forms and Code
• Web Sample Forms and Code
• Business Layer
• Data Access Layer

3. SetFocus Library System
• Introduction:
• This project is a simple library administration application.
• Audience:
• The typical users would be librarians and library volunteers.
• Project Goals:
• Both Windows and web based interfaces
• Handle all common library functions (e.g. Check a book out, Add
a new library member, etc.) with minimal required training.
• Easily maintained code.
• Appropriate error handling.
• Validation for all entered fields.

4. Windows – Main Interface
The main interface window provides access to all the main functions via the menu bar or tool strip. The grid view also
provides a context menu for item related tasks.

5. Windows – Add Members
Form used to enter a new adult member. Fields are validated to ensure proper formatting.
Form used to add a new juvenile member. The Parent ID field is checked against the database to ensure that it is valid.

6. Windows – Check-In/Out
Check in form used to process items that have been returned.
Check out form used to process items when a member wishes to take an item from the library

7. Windows – Validation
• Validation is performed at form level
if (!IsValidName(firstNameTextBox.Text))
{
if (FirstName.Length == 0)
ValidatorErrorProvider.SetError(firstNameTextBox, "You must provide a valid first name");
else
ValidatorErrorProvider.SetError(firstNameTextBox, "The first name must be capitalized and contain only letters");
isValid = false;
}
else
ValidatorErrorProvider.SetError(firstNameTextBox, string.Empty);
• Common validation is re-factored into separate methods
private bool IsValidName(string name)
{
return Regex.IsMatch(name, @"^[A-Z][a-zA-Z]{0,14}$");
}
private bool IsValidPhone(string phone)
{
if(phone.Length > 0)
return Regex.IsMatch(phone, @"^([0-9]{3})[0-9]{3}-[0-9]{4}$");
return true;
}

8. Web – Main Interface
Main interface of the web application. Navigation is done view the links along the left side. The system has a security feature that only
allows registered librarians and volunteers access the interface.

9. Web – Get Member Info
Display of member information. Juvenile members also list the adult member ID and the member’s birth date.

10. Web – Add New Members
Add Adult
Form used for entry of new adult members.
Add Juvenile
Form used for entry of new juvenile members.

11. Web – Add Item
Form used for entering a new item into the system. Form has validation of the ISBN so to prevent duplicate items.

12. Web – Check In Item
Check In Entry
Check In Confirmation
Form for checking in an item upon return.
Check In Error
Page to confirm check in of an item.
Page to notify user of possible error on check in.

13. Web – Check Out Item
Check Out Entry
Check Out Confirmation
Form for checking out an item from the library system.
Check In/Out Confirmation
Page to confirm check out of an item.
Page to confirm a check in of an item before check out.

14. Web – Add New Item
Form used for entering a new item into the system. Form has validation of the ISBN so to prevent duplicate items

15. Web – Validation
• Validation is performed by the html code
<asp:RequiredFieldValidator ID="firstNameReqValidator"
runat="server"
ControlToValidate="firstNameTextBox“
ErrorMessage="You must provide a first name“
ForeColor="White">
</asp:RequiredFieldValidator>
<asp:RegularExpressionValidator ID="firstNameRegExValidator“
runat="server“
ControlToValidate="firstNameTextBox"
ErrorMessage="Firstname must be all lowercase except for the first letter“
ForeColor="White“
ValidationExpression="^[A-Z][a-zA-Z]{0,14}$">
</asp:RegularExpressionValidator>

16. Business Layer
• Packages objects to pass to Data Access Layer
public short AddAdultMember(string firstName, string middleInitial, string lastName, string street, string city, string state, string zipcode, string
phone
{
AdultMember member = new AdultMember();
member.FirstName = firstName;
member.MiddleInitial = middleInitial;
member.LastName = lastName;
member.Street = street;
member.City = city;
member.State = state;
member.ZipCode = zipcode;
member.PhoneNumber = phone;
try
{
lda.AddMember(member);
return member.MemberID;
}
catch (LibraryException ex)
{
throw new LibraryException(ex.LibraryErrorCode, CreateErrorCodeString(ex.LibraryErrorCode));
}
}

17. Business Layer
• Converts Data Access errors to appropriate Business Errors
private string CreateErrorCodeString(ErrorCode code)
{
string message;
switch (code)
{
case ErrorCode.AddAdultFailed:
message = "Failed to add new member";
break;
case ErrorCode.AddJuvenileFailed:
message = "Failed to add new member.";
break;
case ErrorCode.ItemNotCreated:
message = "Item not created.";
break;
default:
message = "Unsupported ErrorCode.";
break;
}
return message;
}

18. Data Access Layer
• Database is accessed through Stored Procedures
using (SqlConnection con = new SqlConnection(Properties.Settings.Default.LibraryConnectionString))
{
using (SqlCommand cmd = new SqlCommand("CheckIn", con))
{
cmd.CommandType = System.Data.CommandType.StoredProcedure;
cmd.Parameters.AddWithValue("@isbn", isbn);
cmd.Parameters.AddWithValue("@copy_no", copyNumber);
con.Open();
cmd.ExecuteNonQuery();
}
}
• Database errors are caught and passed to the Business Layer
catch (SqlException ex)
{
if (ex.Number == 50009 || ex.Number == 50010)
throw new LibraryException(ErrorCode.CheckInFailed, "You must provide a isbn AND a copy number");
if (ex.Number == 50011)
throw new LibraryException(ErrorCode.ItemNotFound);
if (ex.Number == 50014)
throw new LibraryException(ErrorCode.ItemNotOnLoan);
if (ex.Number == 50002)
throw new LibraryException(ErrorCode.GenericException);
throw;
}