Description

Version 3.4

When disaster hits a populated area, the most critical task is to provide immediately affected people with what they need as quickly and as efficiently as possible.
This project creates an application that manages the list of goods that need to be shipped to ae disaster area. The application tracks the quantity of items needed, tracks the quantity on hand, and stores the information in a file for future use.
There are two categories for the types of goods that need to be shipped:
To complete this project you will need to create several classes that encapsulate your solution.

OVERVIEW OF THE CLASSES TO BE DEVELOPED

The classes used by the application are:
Error
Good
A class that manages a non-perishable good object.
Perishable
iGood
An interface to the Good hierarchy. This interface exposes the features of the hierarchy available to the application. Any “iGood” class can
• read itself from the console or write itself to the console
• save itself to a text file or load itself from a text file
• compare itself to a unique C-style string identifier
• determine if it is greater than another good in the collating sequence
• report the total cost of the items on hand
• describe itself
• update the quantity of the items on hand
• report its quantity of the items on hand
• report the quantity of items needed
• accept a number of items
Using this class, the client application can
• save its set of iGoods to a file and retrieve that set at a later time
• read individual item specifications from the keyboard and display them on the screen
• update information regarding the number of each good on hand

THE CLIENT APPLICATION

The client application manages the iGoods and provides the user with options to
• list the Goods
• display details of a Good
• add a Good
• add items of a Good
• update the items of a Good
• delete a Good
• sort the set of Goods

PROJECT CLASS DIAGRAM

PROJECT DEVELOPMENT PROCESS

In order to earn credit for the whole project, you must complete all milestones and assemble them for the final submission.

FILE STRUCTURE OF THE PROJECT

Each class belongs to its own module. Each module has its own header (.h) file and its own implementation (.cpp) file. The name of each file without the extension is the name of its class.

All the code developed for this application belongs to the aid namespace.

MILESTONE 2: THE ERROR MODULE

The Error class manages the error state of client code and encapsulates the last error message.

Any client can define and store an Error object. If a client encounters an error, the client can set its Error object to an appropriate message. The client specifies the length of the message.

The Error object reports whether or not any error has occurred. The isClear() query on the object reports if an error has occurred. If an error has occurred, the object can display the message associated with that error. The object can be send its message to an std::ostream object.

Complete your implementation of the Error class based on the following information:
Private member: Data member:
A pointer that holds the address of the message, if any, stored in the current object.

Public member functions:
No/One Argument Constructor:
explicit Error(const char* errorMessage = nullptr);
This constructor receives the address of a C-style null terminated string that holds an error message.
• If the address is nullptr, this function puts the object into a safe empty state.
• If the address points to an empty message, this function puts the object into a safe empty state.
• If the address points to a non-empty message, this function allocates memory for that message and copies the message into the allocated memory.
Error(const Error& em) = delete;
• A deleted copy constructor prevents copying of any Error object.

Error& operator=(const Error& em) = delete;
• A deleted assignment operator prevents assignment of any Error object to the current object.

virtual ~Error();
• This function de-allocates any memory that has been dynamically allocated by the current object.

void clear();
• This function clears any message stored by the current object and initializes the object to a safe empty state.

bool isClear() const;
• This query reports returns true if the current object is in a safe empty state.

void message(const char* str);
This function stores a copy of the C-style string pointed to by str:
• de-allocates any memory allocated for a previously stored message
• if str points to a non-empty message, this function allocates the dynamic memory needed to store a copy of str (remember to include 1 extra byte for the null terminator) and copies the message into that memory
• if str points to an empty message, this function puts the current object in a safe empty state.

const char* message() const;
• if the current object is not in a safe empty state, this query returns the address of the message stored in the object
• if the current object is in a safe empty state, this query returns nullptr.
Helper operator:
operator<<
• This operator sends an Error message, if one exists, to an std::ostream object and returns a reference to the std::ostream object.
• If no message exists, this operator does not send anything to the std::ostream object and returns a reference to the std::ostream object.
Testing:
Test your code using the tester program on Visual Studio.

MILESTONE 2 SUBMISSION
Upload Error.h and Error.cpp with the tester to your matrix account. Compile and rerun your code and make sure that everything works properly.
Then run the following command from your account: (replace profname.proflastname with your professors Seneca userid)
~profname.proflastname/submit 244_ms2 <ENTER>
and follow the instructions.

Please note that a successful submission does not guarantee full credit for this milestone.