Form Builder; Display a form for uploading an image.

Related topics

Example: Image
Demonstrates the basic use of image API.

File

image_example/image_example.pages.inc, line 79
Page/form showing image styles in use.

Code

function image_example_style_form_submit($form, &$form_state) {

  // When using the #managed_file form element the file is automatically
  // uploaded an saved to the {file} table. The value of the corresponding
  // form element is set to the {file}.fid of the new file.
  //
  // If fid is not 0 we have a valid file.
  if ($form_state['values']['image_example_image_fid'] != 0) {

    // The new file's status is set to 0 or temporary and in order to ensure
    // that the file is not removed after 6 hours we need to change it's status
    // to 1. Save the ID of the uploaded image for later use.
    $file = file_load($form_state['values']['image_example_image_fid']);
    $file->status = FILE_STATUS_PERMANENT;
    file_save($file);

    // When a module is managing a file, it must manage the usage count.
    // Here we increment the usage count with file_usage_add().
    file_usage_add($file, 'image_example', 'sample_image', 1);

    // Save the fid of the file so that the module can reference it later.
    variable_set('image_example_image_fid', $file->fid);
    drupal_set_message(t('The image @image_name was uploaded and saved with an ID of @fid and will be displayed using the style @style.', array(
      '@image_name' => $file->filename,
      '@fid' => $file->fid,
      '@style' => $form_state['values']['image_example_style_name'],
    )));
  }
  elseif ($form_state['values']['image_example_image_fid'] == 0) {

    // Retrieve the old file's id.
    $fid = variable_get('image_example_image_fid', FALSE);
    $file = $fid ? file_load($fid) : FALSE;
    if ($file) {

      // When a module is managing a file, it must manage the usage count.
      // Here we decrement the usage count with file_usage_delete().
      file_usage_delete($file, 'image_example', 'sample_image', 1);

      // The file_delete() function takes a file object and checks to see if
      // the file is being used by any other modules. If it is the delete
      // operation is cancelled, otherwise the file is deleted.
      file_delete($file);
    }

    // Either way the module needs to update it's reference since even if the
    // file is in use by another module and not deleted we no longer want to
    // use it.
    variable_set('image_example_image_fid', FALSE);
    drupal_set_message(t('The image @image_name was removed.', array(
      '@image_name' => $file->filename,
    )));
  }

  // Save the name of the image style chosen by the user.
  variable_set('image_example_style_name', $form_state['values']['image_example_style_name']);
}