PROGRESSIVE ASSESSMENT: Students must show their tutorial work at the end of each session or the beginning of next session and be prepared to answer questions related to the task completed. You are also required to build your assessment folder on a weekly basis. This must contain hard copies of class listings and other relevant information such as contractual responsibilities of group members, charts and test data for your assignment. The quality and presentation of the work submitted is taken into account in the final grade for the assignments. Participation in the LightViews Project is part of your work requirements to improve your learning about OO testing.

Administration

Eiffel 4 in the Pentium Labs from semester 1 1998

You will be working in groups of 3 for your assignment. As compiled Eiffel programs are very large, you will have to delete the object files of completed work as you proceed through the tutorials and the assignment.

Each group must maintain a folio of work. Work completed during the "BANK" tutorial exercises will result in the creation of sets of Eiffel classes in separate directories. The completed work from tutorial 2 should be copied into a new directory to form the basis for tutorial 3, etc.

rm -r EIFFELGEN is a command you can use within a directory to clear it of all non-source code.

A Bank maintains a set of Customer Accounts. As the bank has just opened, it offers only basic 'On Call' Accounts. Customers may own many accounts. No overdrafts are allowed, and no interest paid. No transaction statements are provided at the moment, but it is intended to provide them in the future. The only customer information maintained by the bank at the moment is the name of each owner.

Design a system to implement Bank Account Processing for a Bank.

1. Identify the objects or classes in your system. It may help to think of them as entities.

2. Define the responsibilities of each class in your system.

3. Try to identify the relationships between the classes - what other classes are involved in assisting a class to carry out a particular responsibility?

4. Describe facilities or routines which will allow customers to deposit and withdraw amounts from their account, and to request an account balance.

5. Where would you place facilities for printing out:

Bank details

Customer details

Account details?

6. What does it mean to create an instance of a class?

Whose responsibility is it to create account and a customer objects?

Whose responsibility is it to:

perform an account withdrawal?

alter the address of a customer?

check if a withdrawal amount is within the credit limit?

7. For each object (class) you have defined, describe:

Its name, Its responsibilities

For each responsibility, collaborators - other classes it interacts with to fulfil a responsibility (if any).

1.Create a sub-directory 'bank-dir2' under your $HOME directory.

Using your favourite editor, enter the text below into a file called bank.e in directory 'bank-dir2':

class BANK

creation make

feature

make is

-- Create an instance of Bank.

do

io.putstring ("Welcome to the Bank")

end -- make

end -- Class BANK

2. Launch eiffelbench (ebench&). You will be prompted to select ACE, choose it and a new window will be created. Just fill in the ROOT line with the name bank (in lower case), and note that the UNIVERSE line lists the directories containing the Eiffel library clusters kernel, structures and support. Save the changes.

3.Click on the Melt button in the system window to produce an executable file called bank. Do not Freeze or Finalise as we will run out of diskspace. The executable is created in a subdir. two levels below the current dir.containing the source files. Change dir. to EIFFELGEN/W_code

4.Execute the program by typing bank from W_code subdir. This will display on your screen the message

Welcome to the Bank

5. Modify bank.e as shown below. Replace the comments with the appropriate requests to ACCOUNT's features.

class BANK

feature

make is

-- Create an instance of Bank

do

io.putstring("Welcome to the Bank");

io.new_line;

-- create an account object and store its reference

-- in a BANK attribute called account_1

-- open account_1

-- deposit $200 in account_1

-- if there are sufficient funds,

-- withdraw $300 from account-1

-- display account-1's details

end -- make

end -- Class BANK

6. Compile your system and test it by typing bank.

7. Add another attribute, account_2, to class BANK.

Create a new instance of class ACCOUNT and assign its reference to account_2. Test bank by asking account_2 to perform some deposits, withdrawals and to display itself.

.............................................................................

1.Create a new directory, bank_dir2a.

Copy the files account.e and bank.e from directory bank_dir2 into bank_dir3.

In bank_dir2a, change class BANK to allow for user interaction in creating, setting up, depositing, withdrawing and displaying an account.

Use MY_FILES for terminal I/O and MENU for manipulating menus. Both of these classes are available for your use.

Create a simple menu interface to make processing easier:

1. Create and set up an account

2. Deposit

3. Withdraw

4. Display

5. Exit

NOTE: Run Eiffelbench in the foreground so that it can read stdin

Introduction to Assignment 1 _

Collections of Objects

1. Create a new directory, bank_dir3. Copy the files Ace, account.e and bank.e from directory bank_dir2a into bank_dir3.

2. We would like to maintain some kind of a collection or list of accounts, indexed by the account number. Browse library class HASH_TABLE to understand how this class works. Discuss how HASH_TABLE would be used to store and access a list of bank accounts. Refine class BANK to provide for access to many accounts.

3. In bank_dir3, change class BANK to allow for the creation and maintenance of many accounts, using HASH_TABLE as the container class for storing accounts.

4. Add a feature display to BANK which will display all the accounts in the hash_table. Refer to Eiffel sample code to help you code the display routines.

5. Start on Inheritance/Polymorphism exercise

. Inheritance/Polymorphism

. Persistence

1.Create a new directory, bank_dir3a.

Copy the files Ace, account.e and bank.e from directory bank_dir3 into bank_dir3a.

2.The bank has decided to provide cheque accounts with overdraft limits,

How does a Cheque account differ from an On-call account?

Define the ADT of a cheque account

What features are common to both On-call and Cheque accounts?

What features are implemented differently for On-call and Cheque accounts?

Define an abstract, deferred class ACCOUNT. Define 2 sub-classes of ACCOUNT, ON-CALL and CHEQUE.

3.Change BANK to allow the user to decide at run-time what kind of new account is to be created. Bank.e will have two local attributes (on_call_account and cheque_account) as well as an_account. Depending on the user's response, create an instance of the appropriate specialised type and assign it to an_account.

Test your code by asking the newly created account to print itself out.

4.Change class BANK so that is uses STORABLE, and as described in lectures, make BANK and all its dependents persistent.

General assistance with the Assignment .

Comparison of Banking system and the assignment.

Assignment

Refer to the Case study description for this assignment.

You are required to produce UML diagrams as part of O-O design and implement the system in Eiffel.

The Programming assignment is divided into stages. It is strongly recommended that you also implement the project in stages. As object oriented system development allows you to 'program by refinement', you will find this involves no extra effort, and gives you achievable milestones. Each stage must be stored on separate directories. A hard copy of the code and documentation is required for each stage.

To be Handed in:

UML diagrams.

Class listings plus other documentation as specified. It is strongly recommended that you keep in separate directories the classes marking the achievement of each stage of the project.

The documentation for the system is checked progressively and the final documentation is due on week 13. More specific submission details are with the Assignment handout.

Documentation must be produced in duplicate: one for the lecturer and the other to be submitted to the tutor. Copy your documentation on to the disc to be provided by the lecturer for ongoing software engineering measurement experiments.