How can I auto-rotate an image on file upload in a custom form?

Question

I'm using the FAPI to provide the user an upload field for an image. The field is:

$form['product_img'] = [
  '#type' => 'managed_file',
  '#description' => 'Upload a PNG or JPG image of the product.',
  '#multiple' => FALSE,
  '#required' => TRUE,
  '#upload_location' => 'public://',
  '#upload_validators' => [
    'file_validate_is_img' => [],
    'file_validate_extensions' => ['png jpg jpeg']
  ]
];

A lot of the users are uploading images taken with their mobile device, resulting in the image in landscape.

The solutions I've seen involve the default file upload widget, but I need something that will automatically rotate the image after the upload.

Answer 1

you can try the next code. You will have to create a new image style which rotates the image and then use it in prerendering on image preview.

$form['product_img'] = [
  '#type' => 'managed_file',
  '#description' => 'Upload a PNG or JPG image of the product.',
  '#multiple' => FALSE,
  '#required' => TRUE,
  '#upload_location' => 'public://',
  '#upload_validators' => [
    'file_validate_is_img' => [],
    'file_validate_extensions' => ['png jpg jpeg']
  ],
  '#process' => array('custom_managed_file_element_process'),
];


// Process callback

function custom_managed_file_element_process($element, &$form_state, $form) {

  $element = file_managed_file_process($element, $form_state, $form);
  
  $element['#pre_render'][] = 'custom_managed_file_element_preview';
  
  return $element;
}


function custom_managed_file_element_preview(array $element) {

  if (empty($element['#file'])) {
    hide($element['remove_button']);
  }
  else {

    $file = $element['#file'];
    hide($element['upload']);
    hide($element['upload_button']);

      $info = image_get_info($file->uri);
      $variables = [
        'alt' => $file->filename,
        'path' => $file->uri,
        'style_name' => 'thumbnail', // change your style name here 
        'attributes' => [
          'class' => ['upload-preview'],
        ],
      ];

      if (is_array($info)) {
        $variables += $info;
      }

      $element['preview'] = [
        '#type' => 'markup',
        '#weight' => -150,
        '#markup' => theme('image_style', $variables)
      ];
    
  }

  return $element;

}