PHP and MySQL Web Development 4th Ed-tqw-_darksiderg

Implementing an Administration Interface
647
Figure 28.15
The edit_book_form.php script gives the administrator
access to edit book details or delete a book.
This form is, in fact, the same one used to get the book’s details in the first place.We
built an option into that form to pass in and display existing book data.We did the same
thing with the category form.To see what we mean, look at Listing 28.19.
Listing 28.19 display_book_form() Function from admin_fns.php—Form That
Does Double Duty as an Insertion and Editing Form
function display_book_form($book = '') {
// This displays the book form.
// It is very similar to the category form.
// This form can be used for inserting or editing books.
// To insert, don't pass any parameters. This will set $edit
// to false, and the form will go to insert_book.php.
// To update, pass an array containing a book. The
// form will be displayed with the old data and point to update_book.php.
// It will also add a "Delete book" button.
// if passed an existing book, proceed in "edit mode"
$edit = is_array($book);