avoid duplicates in flash based messaging - php

Question

I am using a php session-based flash messenger available here. The issue is sometimes I get multiple messages of the same type when I generate errors, display messages, so on and so fourth. This is mostly due to some AJAX issues. Assuming that I wanted to only apply a fix in the display code here:
public function display($type = 'all', $print = true)
{
$messages = '';
$data = '';
if (!isset($_SESSION['flash_messages'])) {
return false;
}
// print a certain type of message?
if (in_array($type, $this->msgTypes)) {
foreach ($_SESSION['flash_messages'][$type] as $msg) {
$messages .= $this->msgBefore . $msg . $this->msgAfter;
}
$data .= sprintf($this->msgWrapper, $this->msgClass, $this->msgClassPrepend.'-'.$type, str_replace('messages', 'autoclose',$this->msgClassPrepend.'-'.$type), $messages);
// clear the viewed messages
$this->clear($type);
// print ALL queued messages
} elseif ($type == 'all') {
$counter = 1;
foreach ($_SESSION['flash_messages'] as $type => $msgArray) {
$count = $counter++;
$messages = '';
foreach ($msgArray as $msg) {
$messages .= $this->msgBefore . $msg . $this->msgAfter;
}
$data .= sprintf($this->msgWrapper, $this->msgClass, $this->msgClassPrepend.'-'.$type, str_replace('messages', 'autoclose', $this->msgClassPrepend.'-'.$type), $messages);
}
// clear ALL of the messages
$this->clear();
// invalid message type?
} else {
return false;
}
// print everything to the screen or return the data
if ($print) {
echo $data;
} else {
return $data;
}
}
How would I make it so that duplicate messages are detected on a 1 for 1 basis. So if the message is "Hello" and "Hello" and "Hello." I can remove one of the first two, and keep the later as it is a different message so to speak. All the workarounds I can think of would be overly complex, and I was wondering if anyone could think of a simple solution.
Additional info: display is encased in class Messages and a new message is created with
$msg = new Messages();
$msg->add('e', 'Some error here.');

Answer 1

You could simply run the message array through array_unique() before the $messages string is built. For example, these two additions to the display method should do the trick...
if (in_array($type, $this->msgTypes)) {
$filtered = array_unique($_SESSION['flash_messages'][$type]);
foreach ($filtered as $msg) {
and...
foreach ($_SESSION['flash_messages'] as $type => $msgArray) {
$count = $counter++;
$messages = '';
$filtered = array_unique($msgArray);
foreach ($filtered as $msg) {
Alternatively, you could override the add method with a unique check. For example
public function add($type, $message, $redirect_to = null, $ignoreDuplicates = true) {
// snip...
// wrap the array push in this check
if (!($ignoreDuplicates && in_array($message, $_SESSION['flash_messages'][$type]))) {
$_SESSION['flash_messages'][$type][] = $message; // this is the existing code
}
// snip...
}