Project #10 Solution

You will be writing a Library simulator. It will have  three  classes: Book, Patron and Library.  To make  things a little simpler for you, I am supplying you with the three  .hpp files. You will write the three  implementation files.  You should not alter the provided  .hpp files.

 

 

 

A couple of notes:

 

•   The vector::erase() function lets you delete an element of a vector,  shifting over all the elements after it.

•   You'll see in Book.hpp  a line that says "class Patron;".   That is a forward declaration.  It

doesn't say anything about  the definition of the Paton class, but it promises the compiler that there  will be a type named Patron. The reason we don't just say

"#include Patron.hpp" is that both Book and  Patron need to know about  each other,  but they can't  both #include the other because that would create a cyclic dependency.

 

Here  are  descriptions of the three  classes: Book:

•   idCode - a unique identifier for a Book (think library bar code,  not ISBN) - you can assume uniqueness, you don't have  to enforce it

•   title - cannot be assumed to be unique

•   author  - the idCode, title and  author  don't need set methods, since  they will never change after the object has been created, therefore these fields can be initialized directly within the constructor

•   location - a Book can be either on the shelf, on the hold shelf, or checked out

•   checkedOutBy - pointer to the Patron who has it checked out (if any)

•   requestedBy - pointer to the Patron who has requested it (if any); a Book can only be requested by one  Patron at a time

•   dateCheckedOut - when a book is checked out, this will be set to the currentDate of the

Library

•   CHECK_OUT_LENGTH - constant that gives how long a Book can  be checked out for

•   constructor - takes an idCode, title and  author;  checkedOutBy and requestedBy should be initialized to NULL; a new Book should be on the shelf

•   some get and set methods

Patron:

 

•   idNum - a unique identifier for a Patron - you can  assume uniqueness, you don't have to enforce it

•   name - cannot be assumed to be unique

•   checkedOutBooks - a vector of pointers to Books that Patron currently has checkedOut

•   fineAmount - how much the Patron owes the Library in late fines (measured in dollars);

this is allowed to go negative

•   a constructor that takes an idNum and name and initializes fineAmount to zero

•   some get methods

•   addBook - adds the specified Book to checkedOutBooks

•   removeBook - removes the specified Book from checkedOutBooks

•   amendFine - a positive argument increases the fineAmount, a negative one decreases it

 

 

 

Library:

 

•   holdings - a vector  of pointers to Books in the Library

•   members - a vector of pointers to Patrons in the Library

•   currentDate - stores the current  date  represented as an integer number of "days" since the Library object was created

•   a constructor that initializes the currentDate to zero

•   addBook - adds the parameter to holdings

•   addPatron - adds the parameter to members

•   getBook  - returns a pointer to the Book corresponding to the ID parameter, or NULL if no such Book is in the holdings

•   getPatron - returns a pointer to the Patron corresponding to the ID parameter, or NULL

if no such  Patron is a member

•   In checkOutBook, returnBook and requestBook, check  the listed conditions in the order given - for example, if checkOutBook is called with an invalid Book ID and an invalid Patron ID, it should just return  "book not found"

•   checkOutBook

•   if the specified Book is not in the Library, return "book not found"

•   if the specified Patron is not in the Library, return "patron  not found"

•   if the specified Book is already checked out, return "book already checked out"

•   if the specified Book is on hold by another Patron, return "book on hold by other patron"

•   otherwise update the Book's checkedOutBy, dateCheckedOut and Location; if the Book was on hold for this Patron, update requestedBy; update the Patron's checkedOutBooks; return "check  out successful"

•   returnBook

•   if the specified Book is not in the Library, return "book not found"

•   if the Book is not checked out, return "book already in library"

•   update the Patron's checkedOutBooks; update the Book's location depending on whether another Patron has requested it; update the Book's checkedOutBy; return "return successful"

•   requestBook

•   if the specified Book is not in the Library, return "book not found"

•   if the specified Patron is not in the Library, return "patron  not found"

•   if the specified Book is already requested, return "book already on hold"

•   update the Book's requestedBy; if the Book is on the shelf, update its location to on hold; return  "request successful"

•   payFine

•   takes as a parameter the amount that is being paid (not the negative of that amount)

•   if the specified Patron is not in the Library, return "patron  not found"

•   use amendFine to update the Patron's fine; return "payment successful"

•   incrementCurrentDate

•   increment current  date;  increase each Patron's fines by 10 cents for each overdue Book they have  checked out (using amendFine)

•   If a book is checked out on day 0, then on day 1, the patron  has had  it for 1 day.

On day 21, the patron  has had it for 21 days, so it is still not overdue.  On day

22, the book is overdue and fines will be charged.

•   be careful  - a Book  can be on request without  its location being the hold shelf (if another Patron has it checked out);

 

 

 

One limited example of how your classes might be used is: Book   b1("123", "War   and Peace", "Tolstoy"); Book   b2("234", "Moby   Dick", "Melville");

Book   b3("345",  "Phantom Tollbooth", "Juster");

Patron p1("abc", "Felicity"); Patron p2("bcd",  "Waldo");

Library lib;

lib.addBook(&b1); lib.addBook(&b2); lib.addBook(&b3); lib.addPatron(&p1); lib.addPatron(&p2); lib.checkOutBook("bcd", "234");

for (int i=0; i<7; i++)

lib.incrementCurrentDate();

lib.checkOutBook("bcd", "123"); lib.checkOutBook("abc", "345"); for (int  i=0; i<24; i++)

lib.incrementCurrentDate();

lib.payFine("bcd", 0.4);

double  p1Fine =  p1.getFineAmount();

double  p2Fine =  p2.getFineAmount();

This example obviously doesn't include all of the functions described above. You are responsible for testing all of the required functions to make sure they operate as specified.

 

 

You must submit on TEACH: Book.cpp, Patron.cpp, and Library.cpp.  You do not need to submit the .hpp files.

 

 

In the main method you use for testing, you should only need to #include Library.hpp. Remember that your compile command needs to list all four .cpp files.

 

 

Just  to think about:  There  are six possible changes in the location of a Book.  Can  all six occur?

 

 

There  are a lot of details here  - it's entirely possible I omitted  something or mis-stated something. If you think that is the case, I encourage you to ask  me about  it.