Drupal 7 retain file upload

I have a file upload form

how can I retain this file when there are other validation errors so that the user doesn't have to upload the file again?

I tried this in my validation functi开发者_Python百科on but it doesn't work:

function mymodule_someform_validate($form, &$form_state) {
  $form_state["values"]["some_field"] = some_value;
}

the $form_state["values"] variable is not available in my form definition function - mymodule_someform($form, &$form_state)

Any ideas?

Just use the managed_file type, it'll do it for you:

$form['my_file_field'] = array(
  '#type' => 'managed_file',
  '#title' => 'File',
  '#upload_location' => 'public://my-folder/'
);

And then in your submit handler:

// Load the file via file.fid.
$file = file_load($form_state['values']['my_file_field']);

// Change status to permanent.
$file->status = FILE_STATUS_PERMANENT;

// Save.
file_save($file);

If the validation fails and the user leaves the form, the file will be automatically deleted a few hours later (as all files in the file_managed table without FILE_STATUS_PERMANENT are). If the validation doesn't fail, the submit handler will be run and the file will be marked as permanent in the system.

Admin form example for others who may be looking:

function example_admin_form(){  

  $form = array();  

  $form['image'] = array(
      '#type' => 'managed_file',
      '#name' => 'image',
      '#title' => t('upload your image here!'),
      '#default_value' => variable_get('image', ''),
      '#description' => t("Here you can upload an image"),
      '#progress_indicator' => 'bar',
      '#upload_location' => 'public://my_images/'
  );

  // Add your submit function to the #submit array
  $form['#submit'][] = 'example_admin_form_submit';

  return system_settings_form($form);
}

function example_admin_form_submit($form, &$form_state){

  // Load the file
  $file = file_load($form_state['values']['image']);

  // Change status to permanent.
  $file->status = FILE_STATUS_PERMANENT;

  // Save.
  file_save($file);

}