PHP rotated image is blank - php

Question

I'm using the following php code to save images from various devices. All works fine except iPhone images appearing sideways. I have found a way to fix this by rotating the image before it's saved. However when I upload the image it does not appear on my webpage and in my file manager it still appears sideways. Am I targeting the wrong file to rotate? Or am I using something else incorrectly?
Here's my code:
$file = $_FILES["newsnap"];
$id = $_SESSION['id'];
$username = $_SESSION['username'];
$aboutitems = nl2br(mysqli_real_escape_string($database, $_POST['about-snap']));
$uploadloc = mkdir("../$username/");
$image_temp = $_FILES["newsnap"]['tmp_name'];//Temporary location
$filename = mysqli_real_escape_string($database, htmlentities($file["name"]));
$sourcePath = $image_temp; // source path of the file
$exif = exif_read_data($sourcePath);
$orientation = $exif['Orientation'];
switch($orientation)
{
case 3:
$sourcePath = imagerotate($sourcePath, 180, 0);
break;
case 6:
$sourcePath = imagerotate($sourcePath, -90, 0);
break;
case 8:
$sourcePath = imagerotate($sourcePath, 90, 0);
break;
}
$targetPath = "../$username/$filename"; // Target path where file is to be stored
move_uploaded_file($sourcePath, $targetPath) ; // Moving Uploaded file
$added = date("y.m.d");
mysqli_query($database, "INSERT INTO piqs(userid, chicpiq, aboutpic, added) VALUES('$id', '$targetPath', '$aboutitems', '$added')");
The code works perfectly fine without the below code. I added code below only to rotate a sideways image:
$exif = exif_read_data($sourcePath);
$orientation = $exif['Orientation'];
switch($orientation)
{
case 3:
$sourcePath = imagerotate($sourcePath, 180, 0);
break;
case 6:
$sourcePath = imagerotate($sourcePath, -90, 0);
break;
case 8:
$sourcePath = imagerotate($sourcePath, 90, 0);
break;
}
Thank you for your help.

Answer 1

When I see it correctly $sourcePath is a variable to the file path, which can't be rotated...
See http://php.net/manual/en/function.imagerotate.php, you have to pass the opened resourcere of the picture. So you have to do something like this
$oldImage = ImageCreateFromJPEG($sourcePath);
switch($orientation){
case 3:
$newImage = imagerotate($oldImage, 180, 0);
break;
case 6:
$newImage = imagerotate($oldImage, -90, 0);
break;
case 8:
$newImage = imagerotate($oldImage, 90, 0);
break;
default:
$newImage = $oldImage;
}
imagejpeg($newImage, $targetPath, 90);