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

Adding Ajax Elements to Earlier Projects
881
Finally, and regardless of the errors in attempting to add a URL, the user’s existing bookmarks
are displayed.You can see this result in Figure 34.8.
Figure 34.8
Success—a valid URL has been added.
Although the core functionality around adding a bookmark has been successfully Ajaxenabled,
a few elements still need some work. For instance, the add_bm() function in the
url_fns.php file contains some exceptions that could be handled differently to produce
an error message in this new system. Listing 34.10 shows the existing add_bm() function.
Listing 34.10
Existing add_bm()Function in url_fns.php
function add_bm($new_url) {
// Add new bookmark to the database
echo "Attempting to add ".htmlspecialchars($new_url)."";
$valid_user = $_SESSION['valid_user'];
$conn = db_connect();
// check not a repeat bookmark
$result = $conn->query("select * from bookmark
where username='$valid_user'