Handling Exceptions in the Guestbook Application

General guideline

In this project, you will need to implement exception handling mechanism in the Guestbook application created in Lab. The code I provide to you does not handle any exceptions. Your task is to modify my code so the application handles exceptions using the OOP exception handling approach. Please note only OOP approach is acceptable.

Exceptions to be handled

Following exceptions must be handled by the application:

1. Empty field: All fields in the sign-in form are required. Any filed that is left blank would throw a DataMissingException exception.

2. Invalid date: A valid date should be entered in "mm/dd/yyyy" format. Any date that is not entered in the correct format or is not a valid date would throw a DateException exception. The function named valiatedate defined in the Utilities class validates a date. Notice this method is static, meaning you can call it with the class name.

3. Invalid email address: a valid email should be entered in username@mydomain.domain format. An invalid email would throw an EmailException exception. The function named checkemail defined in the Utilities class checks an email format. Notice this method is also static.

4. Database connection and execution errors: any error related to database connection and execution would throw a DatabaseException exception.

5. Other errors: any error that is not one of the error types listed above would throw an Exception exception.

Handling exceptions

In this application, exception should be handled by simply displaying an error message. The error message is the one that is passed into the constructor when an exception class is instantiated. This message can be retrieved by calling the getMessage() method defined in the Exception class. If you define a different method in your custom exception class to return the error message, then your custom method should be called.

Remember you should use the error view in the views folder to display the error message.

Application should look as such.

Guestbook Application

Thank you for signing our guest book. You will be contacted soon.

Show Guest Book

Guestbook Application

Following guests have signed our guest book:

Name Birth Date Email

Higgins Brian 08/25/1978 hbrian@example.com

Sweets Chris 06/14/1980 schris@example.com

Meggs Peter 04/10/1984 mpeter@mydomain.com

Carter Megan 10/05/1978 cmegan@mydomain.com

1 1 01/01/2000 asdf@asdf.com

nsu iny 01/01/2001 nsuy@yahoo.com

Sign Guest Book

Instructions

Please closely follow instructions below:

1. Creating exception classes: Create a custom exception class for each type of exceptions described in an earlier section. Exception class is available as a built-in class in SPL so you do not need to create it. Make sure your custom exception classes extend the built-in Exception class. Define these exception classes in separate files and store them in the exceptions folder inside the models folder. Please also be advised you should use the conventional underscored format when you name a class file so that you can take advantage of the autoloader class for automatically loading the class definition file when your custom exception class is instantiated with the new command.

2. Modifying application/database.class.php: modify this file so it handles the database-related exceptions. The constructor of the class tries to create a connection to the MySQL server using parameters provided. If the attempt fails, a DatabaseExcetpion exception should be thrown. The exception should be caught and handled.

3. Modifying controllers/guest_controller.class.php: modify this file so it validates guest inputs in the sign in form before they are added into the database table. It throws and handles an exception when an invalid input is detected. Refer to an earlier section for types of invalid inputs. Please also be advised that you may call the validateDate() and validateEmail() methods to validate a date and an email address. These two methods are defined in the Utilities class.

4. Modifying models/guest_model.class.php: The getGuests() and addGuest() methods perform database operations, thus database related exceptions should be handled.