When uploading images from ipad, it happens that some of the images are displayed in landscape format but should be portrait.
So i try to manually rotate this image after upload.
The rotate - function is working; but it needs a flush=all in cms and also on the page to take effect.
any ideas?
thanks.timo.

class MyImageDecorator extends DataExtension{
	
	function getCustomFields(){
		
		$selectionGroup = new OptionsetField(
					   $name = "Rotate",
					   $title = "Rotate",
					   $source = array(
						  "1" => "Rotate CW",
						  "2" => "Rotate CCW"
					   ),
					   $value = ""
					);
					
		$fields = new FieldList();
		$fields->push(new TextField('Title', 'Title'));
		$fields->push($selectionGroup);
		return $fields;
    }
	
	
	function onAfterWrite(){
		if(isset($_POST['Rotate'])){
			$this->Rotate($_POST['Rotate']);
		}	
	 }
	 
	 
	public function Rotate($rotation){
		 
		$angle = $rotation == 1 ? 270 : 90;
		$extension = strtolower($this->owner->getExtension());
		$original = $this->owner->getFullPath();
		$resampled = $original . '.tmp.' . $extension;
		$gd = new GD($original);
		$image_loaded = (method_exists('GD', 'hasImageResource')) ? $gd->hasImageResource() : $gd->hasGD();
		
		if($image_loaded){

			$transformed = $gd;
			$transformed = $transformed->rotate($angle);
			
			if($transformed){
				$transformed->writeTo($resampled);
				unlink($original);
				rename($resampled, $original);
			}
		}
	}

Since you've named the resampled image the same as the original, this seems more like a browser cache issue than a silverstripe problem.
Try ctrl+F5 after making a rotation instead of flushing (although this will be difficult on an ipad - I don't know if it has an equivalent).

Unless you're talking about the wee preview image - this is because it's a separate image all together. You'll need to clear out all cached resamples somehow. I'm not sure there is a native method to do this.
There is a flush generated image task that may provide some insights for you though: http://api.silverstripe.org/3.1/class-FlushGeneratedImagesTask.html
It's probably not advisable to run this every time thoguh, as I believe it will flush ALL generated images, not just the affected one.

Hi Pyromanik!
whats the "wee preview image" ?

i modyfied https://github.com/axllent/silverstripe-scaled-uploads/blob/master/code/ScaledUploads.php
and changed the switch - function in exifRotation
now all images are handled correct from ipad.
Another issue is that i can only access the ipad camera from wee preview and not from gridfield -bulk - upload.
also the cache problem is solved with a dirty rename action.
Its not updating imediatly but when clicking the second save-button on bottom.

class MyImageDecorator extends DataExtension{
	
	public static $max_width = 1200;
	public static $max_height = 1000;
	public static $exif_rotation = true;
	
	
	public function getMaxWidth() {
		$w = Config::inst()->get('MyImageDecorator', 'max-width');
		return ($w) ? $w : self::$max_width;
	}
	public function getMaxHeight() {
		$h = Config::inst()->get('MyImageDecorator', 'max-height');
		return ($h) ? $h : self::$max_height;
	}
	public function getAutoRotate() {
		$r = Config::inst()->get('MyImageDecorator', 'auto-rotate');
		if ($r === 0 || $r == 'false') return false;
		return self::$exif_rotation;
	}
	
	function getCustomFields(){
		
		$selectionGroup = new OptionsetField(
					   $name = "Rotate",
					   $title = "Rotate",
					   $source = array(
						  "1" => "90º CW",
						  "2" => "90º CCW",
						  "3" => "180º"
					   ),
					   $value = ""
					);
					
		$fields = new FieldList();
		$fields->push($selectionGroup);
		return $fields;
    }
	
	
	function onAfterWrite(){
		if(isset($_POST['Rotate'])){
			$this->ManualRotate($_POST['Rotate']);
		}else{
			$this->ExifRotate();
		}
	}
	 
	 
	public function ManualRotate($rotation){
		
		switch($rotation) {
			case 1: // 90 rotate CW
				$angle =  270;
				break;
			case 2: // 90 rotate CCW
				$angle =  90;
				break;
			case 3: // image upside down
				$angle =  180;
				break;
		}
		$extension = strtolower($this->owner->getExtension());
		$original = $this->owner->getFullPath();
		$name = $this->owner->Name;
		$filename = $this->owner->Filename;
		$image = Image::get()->byID($this->owner->ID);
		$resampled = $original . '.tmp.' . $extension;
		$gd = new GD($original);
		$image_loaded = (method_exists('GD', 'hasImageResource')) ? $gd->hasImageResource() : $gd->hasGD();
		
		if($image_loaded){

			$transformed = $gd;
			$transformed = $transformed->rotate($angle);
			
			if($transformed){
				$time = time();
				$transformed->writeTo($resampled);
				unlink($original);
				$this->owner->deleteFormattedImages();
				//rename($resampled, $original);
				$original = preg_replace('/\\.[^.\\s]{3,4}$/', '', $original); // remove Extention
				$orig_Filename = preg_replace('/\\.[^.\\s]{3,4}$/', '', $filename);
				$original = preg_replace('/--.*/', '', $original);
				$orig_Filename = preg_replace('/--.*/', '', $orig_Filename);
				$name = preg_replace('/\\.[^.\\s]{3,4}$/', '', $name);
				$name = preg_replace('/--.*/', '', $name);
				rename($resampled, $original.'--'.$time.'.'.$extension);
				
			
				DB::query("UPDATE File SET Filename='".$orig_Filename.'--'.$time.'.'.$extension."', Name='".$name.'--'.$time.'.'.$extension."' WHERE ID = ".$this->owner->ID."");
				
			}
		}
		
	}
	
	
	
	
	public function ExifRotate() {
		$extension = strtolower($this->owner->getExtension());
		if($this->owner->getHeight() > $this->getMaxHeight() || $this->owner->getWidth() > $this->getMaxWidth()) {
			$original = $this->owner->getFullPath();
			$resampled = $original . '.tmp.' . $extension;
			$gd = new GD($original);
			/* Backwards compatibility with SilverStripe 3.0 */
			$image_loaded = (method_exists('GD', 'hasImageResource')) ? $gd->hasImageResource() : $gd->hasGD();
			if ($image_loaded) {
				
				/* Clone original */
				$transformed = $gd;
				/* If rotation allowed & JPG, test to see if orientation needs switching */
				if ($this->getAutoRotate() && preg_match('/jpe?g/i', $extension)) {
					$switchorientation = $this->exifRotation($original);
					if ($switchorientation) {
						$transformed = $transformed->rotate($switchorientation);
					}
				}
				/* Resize to max values */
				if ($transformed) {
					$transformed = $transformed->resizeRatio($this->getMaxWidth(), $this->getMaxHeight());
				}
				/* Overwrite original upload with resampled */
				if ($transformed) {
					$transformed->writeTo($resampled);
					unlink($original);
					rename($resampled, $original);
				}
			}
		}
	}
	
	public function exifRotation($file) {
		
		$exif = @exif_read_data($file);
		if (!$exif) return false;
		$ort = @$exif['IFD0']['Orientation'];
		if (!$ort) $ort = @$exif['Orientation'];
		switch($ort) {
			case 1:
				return false;
				break;
			case 2:
				return '180';
				break;					
			case 3:
				return '180';
				break;		
			case 4:
				return '180';
				break;	
			case 5:
				return '-90';
				break;	
			case 6:
				return '-90';
				break;	
			case 7:
				return '-90';
				break;	
			case 8:
				return '90';
				break;
			default:
				return false;
		}
	}
	 
	 

> whats the "wee preview image" ?
eg. assets/Uploads/_resampled/*

'wee' is English slang for 'small'.

A bit late maybe, but I think you could call
```
$this->owner->deleteFormattedImages();
```
to refresh the cache of only this specific image after rotating. Then you don't have to rename it etc.

Also found a module which should prevent images from rotating wrongly upon upload altogether; https://github.com/thisisbd/silverstripe-fixjpeg-orientation