Question $1$

Study the following UML class diagram:

The UML class diagram is an initial design of classes for a conference registration

application.

There are three types of registration allowed for the conference: standard registration,

student registration and invited guests registration. The standard registration fee is the

standard fee $($stored in STANDARD$\_$FEE$).$ For those registered as students, the

conference fee is half the price of the standard registration fee. For those registered as

guests, the conference fee is $10\%$ of the standard registration fee.An instance of RegistrationList contains a list of Registration$*.$ No two

registrations are allowed to have attendees with the same e$-$mail addresses, unless the

names are different. You should be able to query a RegistrationList whether a

person $($by the name$)$ is already registered for the conference. A RegistrationList

can also return the number of attendees that are registered for the conference from an

institution. Similarly, you can request the total registration fees for a type $($Registration$,$

$$StudentRegistration$,$GuestRegistration$$ or $$All$)$ of registration. You are expected to

use Qt$$s metaobject system to access the type of a Registration in

RegistrationList.

Write a GUI application that allows users to register for a conference. The GUI should

display the current list of registrations, including the respective registration fees, in the

RegistrationList at all times, using a table widget. The interface should also allow

users to request and view the results of the various operations supported by the

RegistrationList class.

You are allowed to add new features to the classes given in the UML diagram, although

you are not allowed to delete or change the given functions. You can decide on the design

of the GUI, and it can be done manually or using Qt Designer. You are expected to follow

good programming principles.

Extend the solution in Question $1,$ to add another class named

RegistrationListWriter that produces an XML$-$formatted RegistrationList

using DOM as follows:

$..$

$..$

$..$

$..$

$..$

$..$

$..$

Note: $..$ means data has to be filled in based on the Registration objects in the

RegistrationList.

Modify the GUI in Question $1,$ to give the user an option to save the registration list. Allow

the user to choose the file, using the standard file dialog, where the XML formatted

registration list should be saved.

Question $3$

Add another class to Question $2,$ named RegistrationListReader, that can parse

the XML formatted asset list using SAX, and create and return a list of Registration

objects.

To test the RegistrationListReader class, modify the GUI in Question $2,$ to allow

the list of Registrations to be read in so that they can be appended to the

RegistrationList maintained by the application. Note that the user can request to

read in the XML formatted file when there are Registrations, or none, in the

RegistrationList. Use the standard file dialog to assist the user in choosing the XML

formatted file.

Question $4$

Implement a factory class $($RegistrationFactory$)$ using the Factory method design

pattern, which creates and returns a Registration based on an appropriate string

argument and other arguments $($for initializing concrete Registration objects$)$

provided. Make the RegistrationFactory an implementation of the Singleton

pattern.

Modify the solution in Question $3,$ so that the parts of the solution that were creating

concrete Registration objects $($based on the user input and

RegistrationListReader$)$ are replaced by appropriate code to utilise the

RegistrationFactory