} // end rewindFiles
// checks for duplicate ISBN when attempting to add
public Boolean checkForDuplicateRecordAdd(string enteredISBN)
{
string nextRecord;
Boolean isEndOfFile = true;
Boolean success;
int countProcessedRecords = 0;
nextRecord = currentBookFile.getNextRecord(ref isEndOfFile);
while (!isEndOfFile)
{
countProcessedRecords++;
BookClass book = new BookClass();
success = book.createBookObject(nextRecord);
if (success != true)
{
MessageBox.Show
("Unable to create Book Object. Book not created.",
"Book creation failed", MessageBoxButtons.OK, MessageBoxIcon.Stop);
} // end if statement
if (book.bookMatch(enteredISBN) == false)
{
writeOneRecord(nextRecord);
}
else
{
MessageBox.Show
("Book with ISBN: " + enteredISBN + " already exists in our library.", "ISBN error",
MessageBoxButtons.OK, MessageBoxIcon.Stop);
return(true);
}
nextRecord = currentBookFile.getNextRecord(ref isEndOfFile);
}
return(false);
}
public Boolean createBookObject(string s) // IN: string from the Book Text File
{
BookClass thisBook = this;
string[] bookString = s.Split('*');
bookString[0] = bookString[0].Trim();
// Convert ISBN
hiddenISBN = bookString[0];
if (hiddenISBN == "" || hiddenISBN == " ")
{
MessageBox.Show(hiddenISBN +
": ISBN cannot be blank. Book File Corrupt. Execution Terminated.",
"ISBN in Book File Invalid", MessageBoxButtons.OK, MessageBoxIcon.Stop);
return(false);
}
// title string to string (no conversion)
// Checks for blank title
hiddenTitle = bookString[1].Trim();
if (hiddenTitle == " " || hiddenTitle == "")
{
MessageBox.Show(hiddenTitle +
": Title string is empty or Blank. Book File Corrupt. Execution Terminated.",
"Title in Book File Invalid", MessageBoxButtons.OK, MessageBoxIcon.Stop);
return(false);
}
hiddenAuthor = bookString[2].Trim();
// Convert author to string
// Checks for blank author
if (hiddenAuthor == " " || hiddenAuthor == "")
{
MessageBox.Show(hiddenAuthor +
": Author cannot be blank. Book File Corrupt. Execution Terminated.",
"Author in Book File Invalid", MessageBoxButtons.OK, MessageBoxIcon.Stop);
return(false);
}
// Convert price to hiddenPrice
hiddenPrice = bookString[3].Trim();
if (hiddenPrice == " " || hiddenPrice == "")
{
MessageBox.Show(hiddenPrice +
": Price cannot be blank. Book File Corrupt. Execution Terminated.",
"Price in Book File Invalid", MessageBoxButtons.OK, MessageBoxIcon.Stop);
return(false);
}
// Convert quantity to hiddenQuantity
hiddenQuantity = bookString[4].Trim();
if (hiddenQuantity == " " || hiddenQuantity == "")
{
MessageBox.Show(hiddenQuantity +
": Quantity cannot be blank. Book File Corrupt. Execution Terminated.",
"Quantity in Book File Invalid", MessageBoxButtons.OK, MessageBoxIcon.Stop);
return(false);
}
// Convert Last Date of Access to a Date
hiddenDateLastTransaction = bookString[5].Trim();
if (hiddenDateLastTransaction == " " || hiddenDateLastTransaction == "")
{
MessageBox.Show(hiddenDateLastTransaction +
": Date of Last Transaction cannot be blank. Book File Corrupt. Execution Terminated.",
"Date in Book File Invalid", MessageBoxButtons.OK, MessageBoxIcon.Stop);
return(false);
}
//if all data is valid
return(true);
}
