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

Implementing User Functions
717
Listing 30.11
Continued
$arr_row = array($row[0], $row[1],
$listname, $listid);
array_push($list, $arr_row);
}
}
return $list;
}
Again, this function gets the required information—in this case, the details of mail
that has been sent—from the database and builds an array suitable for passing to the
display_items() function.
Subscribing and Unsubscribing
On the list of mailing lists shown in Figure 30.7, each list has a button that enables users
to subscribe to it. Similarly, if users use the Show My Lists option to see the lists to
which they are already subscribed, they will see an Unsubscribe button next to each list.
These buttons activate the subscribe and unsubscribe actions, which trigger the
following two pieces of code, respectively:
case 'subscribe':
subscribe(get_email(), $_GET['id']);
display_items('Subscribed Lists',
get_subscribed_lists(get_email()),
'information', 'show-archive', 'unsubscribe');
break;
case 'unsubscribe':
unsubscribe(get_email(), $_GET['id']);
display_items('Subscribed Lists',
get_subscribed_lists(get_email()),
'information', 'show-archive', 'unsubscribe');
break;
In each case, you call a function (subscribe() or unsubscribe()) and then redisplay a
list of mailing lists the user is now subscribed to by using the display_items() function
again.
The subscribe() and unsubscribe() functions are shown in Listing 30.12.