I am new to this forum and also new to PHP and MySQL. I get the following error when I open a page called view_conversation.page.inc.php:
<?php
$errors = array();
$valid_conversation = (isset($_GET['conversation_id']) && validate_conversation_id($_GET['conversation_id']));
if ($valid_conversation === false){
$errors[] = 'Invalid Conversation ID.';
}
if (isset($_POST['message'])){
if (empty($_POST['message'])){
$errors[] = 'You must enter a message.';
}
if (empty($errors)){
add_conversation_message($_GET['conversation_id'], $_POST['message']);
}
}
if (empty($errors) === false){
foreach ($errors as $error){
}
}
echo $error;
if ($valid_conversation){
/*if (isset($_POST['message'])){
update_conversation_last_view($_GET['conversation_id']);*/
$messages = fetch_conversation_messages($_GET['conversation_id']);
print_r($messages);
/*}else{
$messages = fetch_conversation_messages($_GET['conversation_id']);
update_conversation_last_view($_GET['conversation_id']);
}*/
}
?>
<a href="index.php?page=inbox">Inbox</a>
<a href="index.php?page=logout">Logout</a>
<form action="" method="post">
<p><textarea name="message" rows="10" cols="110"></textarea></p>
<p><input type="submit" value="Add Message" /></p>
</form>
<?php
foreach ($messages as $message){
?>
<?php if ($message['unread']) echo 'unread'; ?>
<p class="name">Username: <?php echo $message['user_name']; ?></p>
<p class="text">Date: <?php echo date('d/m/Y H:i:s', $message['date']); ?></p>
<p>Message: <?php echo $message['text']; ?></p>
<?php
}
?>
It links to functions in the page named private_message.inc.php:
<?php
// Fetches a summary of the conversations.
function fetch_conversation_summary(){
$sql = "SELECT
`conversations`.`conversation_id`,
`conversations`.`conversation_subject`,
MAX(`conversations_messages`.`message_date`) AS `conversation_last_reply`,
MAX(`conversations_messages`.`message_date`) > `conversations_members`.`conversation_last_view` AS `conversation_unread`
FROM `conversations`
LEFT JOIN `conversations_messages` ON `conversations`.`conversation_id` = `conversations_messages`.`conversation_id`
INNER JOIN `conversations_members` ON `conversations`.`conversation_id` = `conversations_messages`.`conversation_id`
WHERE `conversations_members`.`user_id` = {$_SESSION['user_id']}
AND `conversations_members`.`conversation_deleted` = 0
GROUP BY `conversations`.`conversation_id`
ORDER BY `conversation_last_reply` DESC";
$result = mysql_query($sql);
$conversations = array();
while (($row = mysql_fetch_assoc($result)) !== false){
$conversations[] = array(
'id' => $row['conversation_id'],
'subject' => $row['conversation_subject'],
'last_reply' => $row['conversation_last_reply'],
'unread_messages' => ($row['conversation_unread'] == 1),
);
}
return $conversations;
}
// Fetches all of the messages in the given converstion.
function fetch_conversation_messages($conversation_id){
$conversation_id = (int)$conversation_id;
$sql = "SELECT
`conversations_messages`.`message_date`,
`conversations_messages`.`message_date` > `conversations_members`.`conversation_last_view` AS `message_unread`,
`conversations_message`.`message_text`,
`users`.`user_name`
FROM `conversations_messages`
INNER JOIN `users` ON `conversations_messages`.`user_id` = `users`.`user_id`
INNER JOIN `conversations_members` ON `conversations_messages`.`conversation_id` = `conversations_members`.`conversation_id`
WHERE `conversations_messages`.`conversation_id` = {$conversation_id}
AND `conversations_members`.`user_id` = {$_SESSION['user_id']}
ORDER BY `conversations_messages`.`message_date` DESC";
$result = mysql_query($sql);
$messages = array();
while (($row = mysql_fetch_assoc($result)) !== false){
$messages[] = array(
'date' => $row['message_date'],
'unread' => $row['message_unread'],
'text' => $row['message_text'],
'user_name' => $row['user_name'],
);
}
return $messages;
}
/*function fetch_conversation_messages($conversation_id){
$conversation_id = (int)$conversation_id;
$sql = "SELECT
`conversations_messages`.`message_date`,
`conversations_messages`.`message_text`,
`users`.`user_name`
FROM `conversations_messages`
INNER JOIN `users` ON `conversations_messages`.`user_id` = `users`.`user_id`
WHERE `conversations_messages`.`conversation_id` = {$conversation_id}
ORDER BY `conversations_messages`.`message_date` DESC";
$result = mysql_query($sql);
var_dump($result);
$messages = array();
while (($row = mysql_fetch_assoc($result)) !== false){
$messages[] = array(
'date' => $row['message_date'],
'unread' => $row['message_unread'],
'text' => $row['message_text'],
'user_name' => $row['user_name'],
);
var_dump($row);
}
echo count($messages);}*/
// Sets the last view time to the current time for the given conversation.
function update_conversation_last_view($conversation_id){
$conversation_id = (int)$conversation_id;
$time = time() + 18000;
$sql ="UPDATE `conversations_members`
SET `conversation_last_view` = {$time}
WHERE `conversation_id` = {$conversation_id}
AND `user_id` = {$_SESSION['user_id']}";
mysql_query($sql);
}
// Creates a new conversation, making the given users a member.
function create_conversation($user_ids, $subject, $body){
$subject = mysql_real_escape_string(htmlentities($subject));
$body = mysql_real_escape_string(htmlentities($body));
mysql_query("INSERT INTO `conversations` (`conversation_subject`) VALUES ('{$subject}')");
$conversation_id = mysql_insert_id();
$sql = "INSERT INTO `conversations_messages` (`conversation_id`, `user_id`, `message_date`, `message_text`)
VALUES ({$conversation_id}, {$_SESSION['user_id']}, UNIX_TIMESTAMP(), '{$body}')";
mysql_query($sql);
$values = array("({$conversation_id}, {$_SESSION['user_id']}, UNIX_TIMESTAMP(), 0)");
foreach ($user_ids as $user_id){
$user_id = (int)$user_id;
$values = array("({$conversation_id}, {$_SESSION['user_id']}, UNIX_TIMESTAMP(), 0)"); }
$sql = "INSERT INTO `conversations_members` (`conversation_id`, `user_id`, `conversation_last_view`, `conversation_deleted`)
VALUES " . implode(", ", $values);
mysql_query($sql);
}
// Checks to see if the given user is a member of the given conversation.
function validate_conversation_id($conversation_id){
$conversation_id = (int)$conversation_id;
$sql = "SELECT COUNT(1)
FROM `conversations_members`
WHERE `conversation_id` = {$conversation_id}
AND `user_id` = {$_SESSION['user_id']}
AND `conversation_deleted` = 0";
$result = mysql_query($sql);
return(mysql_result($result, 0) == 1);
}
// Adds a message to the given conversation.
function add_conversation_message($conversation_id, $text){
$conversation_id = (int)$conversation_id;
$text = mysql_real_escape_string(htmlentities($text));
$sql = "INSERT INTO `conversations_messages` (`conversation_id`, `user_id`, `message_date`, `message_text`)
VALUES ({$conversation_id}, {$_SESSION['user_id']}, UNIX_TIMESTAMP(), '{$text}')";
mysql_query($sql);
mysql_query("UPDATE `conversations_members` SET `conversation_deleted` = 0 where `conversation_id = {$conversation_id}");
}
// Deletes (or marks as deleted) a given conversation.
function delete_conversation($conversation_id){
$conversation_id = (int)$conversation_id;
$sql = "SELECT DISTINCT `conversation_deleted`
FROM `conversations_members`
WHERE `user_id` != {$_SESSION['user_id']}
AND `conversation_id` = {$conversation_id}";
$result = mysql_query($sql);
//if (mysql_num_rows($result) == 1 && mysql_result($result, 0) == 1){
if (mysql_num_rows($result) == 0){
mysql_query("DELETE FROM `conversations` WHERE `conversation_id` = {$conversation_id}");
mysql_query("DELETE FROM `conversations_members` WHERE `conversation_id` = {$conversation_id}");
mysql_query("DELETE FROM `conversations_messages` WHERE `conversation_id` = {$conversation_id}");
}else{
$sql = "UPDATE `conversations_members`
SET `conversation_deleted` = 1
WHERE `conversation_id` = {$conversation_id}
AND `user_id` = {$_SESSION['user_id']}";
mysql_query($sql);
}
}
?>
Please help me with this.
That means that you are trying to loop through an array using foreach, but either the array does not have anything in it, or you are trying to loop through something that is not an array (like a string). The PHP error should give you a line number so that you can see where the foreach is being called.
This warning error means that you are trying to loop through a non-array variable, or an empty array .
for solving it, put an if before your foreach, like this :
$messages = ...
if($messages){
foreach($messages as $message){
// do something
}
}