Object Oriented PHP & Recursion

[Dan06]

I have a php object that performs a series of sql queries and displays the results, the object is supposed to call itself if a particular value is not null. Currently, the object works correctly the first time through the code - the correct information is displayed. But when it comes to calling itself something goes wrong. The page displays the following error:

Connection Interrupted.

The connection to the server was reset while the page was loading.

The network link was interrupted while negotiating a connection. Please try again.

 

Below is the php object code, anyone know where I've gone wrong? Thanks.

class messageDetails{

public function displayDetails($msgLinkEnd){

$format = new stringFormat();
$dbconn = new dbConnection();

... SQL QUERIES ...

	do{
		echo '<div class="displayMsg">' . '<img src="' . $profileImgLoc["profileImage"] . '" width="100px" height="100px" />' . ' ' . $msgInfo["msgDate"] . ' ' . '<a href=message_details.php?msgId=' . $msgInfo["msgId"] . '>' . $msgInfo["msgContent"] . '</a>' . '</div>';
}
	while ($msgInfo = mysql_fetch_assoc($msgQueryResult));

	if ($msgInfo["msgParent"] != NULL || $msgInfo["msgParent"] != "NULL" || $msgInfo["msgParent"] != ""){
		$this->displayDetails($msgInfo["msgId"]);
	} else { 
		return true;
	}

} // end displayDetails function
} // end messageDetails class

[premiso]

That usually means your recursive loop never exits, it just keeps looping itself.

 

Check your logic and make sure it that it exits and does not just keep going and going and going.

[.josh]

Assuming this:

 

$dbconn = new dbConnection();

 

establishes a new database connection (like mysql_connect), I would suggest removing that from your recursive function.  Not sure what dbConnection() looks like, but if you're not assigning the resource to a variable, that line + recursive function = opening up lots and lots of connections.

[printf]

That function displayDetails will never work the way you have it. Change the do{} to while() so it works the way it should! If you don't understand why then you need to study your logic. If you use do{}, when that loop  finishes, $msgInfo  will always equal false because there are no more rows. So your if(s) will never get satisfied. Turn error reporting on and you will see all the errors!

[Dan06]

The problem seems to be caused because I assigned mysql_fetch_assoc($msgQueryResult) twice. Below is the entire code. I used the do rather than a while loop because when I used a while loop the image query did not work.

 

 class messageDetails{

public function displayDetails($msgLinkEnd){

$format = new stringFormat();
$dbconn = new dbConnection();

	$msgParentQuery = sprintf("SELECT message_content.msgParent FROM utilist.message_content WHERE message_content.msgId = %s",
	$format->formatValue($msgLinkEnd));

	$parentQueryResult = mysql_query($msgParentQuery, $dbconn->conn()) or die("Parent Message Query Error: " . $msgParentQuery . mysql_error());
	$parentId = mysql_fetch_assoc($parentQueryResult);

	$messageQuery = sprintf("SELECT msgSender, message_content.msgId, message_content.msgParent, msgDate, msgContent FROM utilist.message_outbox, utilist.message_content WHERE message_content.msgId = %s AND message_outbox.msgId = message_content.msgId",
$format->formatValue($parentId["msgParent"]));

	$msgQueryResult = mysql_query($messageQuery, $dbconn->conn()) or die("Outbox Message Query Error: " . $messageQuery . " " . mysql_error());
	$msgFields = mysql_fetch_assoc($msgQueryResult);

	$membershipIdQuery = sprintf("SELECT membershipId FROM utilist.user_information WHERE userId = %s",
	$format->formatValue($msgFields["msgSender"]));

	$memIdQueryResult = mysql_query($membershipIdQuery, $dbconn->conn()) or die("Membership Id Query Error: " . $membershipIdQuery . " " . mysql_error());
	$membershipIdValue = mysql_fetch_assoc($memIdQueryResult);

	$profileImgQuery = sprintf("SELECT profileImage FROM utilist.profile WHERE membershipId = %s",
	$format->formatValue($membershipIdValue["membershipId"]));

	$profileImgResult = mysql_query($profileImgQuery, $dbconn->conn()) or die("Profile Image Query Error: " . $profileImgQuery . " " . mysql_error());
	$profileImgLoc = mysql_fetch_assoc($profileImgResult);

	while ($msgInfo = mysql_fetch_assoc($msgQueryResult)){
		echo '<div class="displayMsg">' . '<img src="' . $profileImgLoc["profileImage"] . '" width="100px" height="100px" />' . ' ' . $msgInfo["msgDate"] . ' ' . '<a href=message_details.php?msgId=' . $msgInfo["msgId"] . '>' . $msgInfo["msgContent"] . '</a>' . '</div>';
}
	/*
	if ($msgInfo["msgParent"] != NULL || $msgInfo["msgParent"] != "NULL" || $msgInfo["msgParent"] != ""){
		$this->displayDetails($msgInfo["msgId"]);
	} else{ 
		return true;
	}
	*/

} // end displayDetails function
} // end messageDetails class