//Handles searching the book file for the specified book, as well as deleting/updating files.
//Flags are "delete"/"update". Add is handled with a boolean and then calling the addBook method.
//Doing it this way prevents having to re-search/scan the file for deleting/updating.
//While you could do delete/update in similar ways it revolves around constantly keeping track
//of the Reader/Writer which I feel is more difficult to follow than this method.
//However, this method does kind of do a lot and is a pain to read through.
public bool bookSearch(ref Book book, string isbn, string flag = "")
{
sw = new StreamWriter(tempFile);
sr = new StreamReader(sourceFile);
currentBook = book; //Store original book passed
string line;
bool found = false;
flag.ToLower();
while ((line = sr.ReadLine()) != null)
{
string[] bookInfo = line.Split('|');
//ISBN ID Validatio(Two groups of 3 digits delimited by hyphen)
if (Book.ValidateISBNFormat(bookInfo[0]))
{
if (bookInfo[0] == isbn && flag == "") //Just a search, return the book that was being looked for/dont modify file
{
book = new Book(bookInfo);
found = true;
sw.Close();
sr.Close();
return(found);
}
else if (bookInfo[0] == isbn && flag == "delete") //Record found, delete it? If yes, just skip writing.
{
Book deleteBook = new Book(bookInfo);
DialogResult dr = MessageBox.Show("Book with ISBN: " + isbn + " found.\r\n" +
String.Join(Environment.NewLine, deleteBook.BookInfo()) + "\r\nIs this the book you wish to delete?",
"Delete Book", MessageBoxButtons.YesNo);
if (dr == DialogResult.Yes)
{
found = true;
}
}
else if (bookInfo[0] == isbn && flag == "update") //Update a record
{
sw.WriteLine(currentBook.ToString());
found = true;
}
else //This book doesn't match the book being searched for, safe to just write it.
{
if (!string.IsNullOrWhiteSpace(line))
{
sw.WriteLine(line);
}
}
}
else //What to do if we have invalid entry in txt file/data corruption
{
if (!string.IsNullOrEmpty(line))
{
MessageBox.Show("Inventory file has issue at ISBN: " + bookInfo[0],
"Data Corruption");//Move to form code probably
return(false);
}
}
}
sr.Close();
sw.Close();
return(found);
}