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

Adding Ajax Elements to Earlier Projects
879
Listing 34.9
Continued
//check that form has been completed
if (!filled_out($_POST)) {
//has not
echo "Form not completely filled out.";
} else {
// has; check and fix URL format if necessary
if (strstr($new_url, 'http://') === false) {
$new_url = 'http://'.$new_url;
}
// continue on to check URL is valid
if (!(@fopen($new_url, 'r'))) {
echo "Not a valid URL.";
} else {
//it is valid, so continue to add it
add_bm($new_url);
echo "Bookmark added.";
}
}
// regardless of the status of the current request
// get the bookmarks this user has already saved
if ($url_array = get_user_urls($_SESSION['valid_user'])) {
display_user_urls($url_array);
}
?>
This version of the script still follows a logical path through possible events, but displays
an appropriate error message without duplicating any other page elements.
The first check is whether the form itself has been filled out. If it has not, an error
message is displayed between the addition form and the user’s current list of stored
bookmarks.You can see this response in Figure 34.6.
The second check is whether the URL is properly formed; if it is not, the string is
transformed into a proper URL and moves on to the next step. In the next step, a socket
is opened and the URL is tested for validity. If it fails, an error message is displayed
between the addition form and the user’s current list of stored bookmarks. However, if
the URL is valid, it is added to the user’s existing list of stored URLs. In Figure 34.7
you can see the response when attempting to add an invalid URL.