tripal/tripal_views/tripal_views_form_elements.inc

<?php

/**
 * @file
 * Form elements used for tripal views
 */

/**
 * Register form elements
 */
function tripal_views_elements() {

  $type['file_upload_combo'] = array(
    '#input' => TRUE,
    '#process' => array('expand_file_upload_combo'),
    '#element_validate' => array('file_upload_combo_validate'),
  );

  return $type;
}

/**
 * Upload File and keep track of previously uploaded files
 * Form element description
 */
function expand_file_upload_combo($element, $edit, $form_state, $complete_form) {

  if (empty($element['#value'])) {
    $element['#value'] = array(
      'items' => '',
      'items_file' => '',
      'file_path' => '',
    );
  }

  $element['#tree'] = TRUE;

  $parents = $element['#parents'];
  $parents[] = 'items';
  $element['items'] = array(
    '#type' => 'textarea',
    '#default_value' => $element['#value']['items'],
  );
  $parents = $element['#parents'];
  $parents[] = 'items_file';
  $element['items_file'] = array(
    '#type' => 'file',
    '#title' =>  'File upload',
    '#default_value' => $element['#value']['items_file'],
  );

  $parents = $element['#parents'];
  $parents[] = 'file_path';
  $element['file_path'] = array(
    '#type' => 'hidden',
    '#default_value' => $element['#value']['file_path'],
  );

  return $element;
}

/**
 * Theme the file upload combo form element
 */
function theme_file_upload_combo($element) {
  return theme('form_element', $element, '<div class="container-inline">' . $element['#children'] . '</div>');
}

/**
 * Validate all content passed into the file upload combo form element
 */
function file_upload_combo_validate($element, &$form) {
  $file = file_save_upload($element['#name'], array());
  if ($file) {
    $form['values'][$element['#name']]['file_path'] = $file->filepath;
    // we need to add our file path to the $_GET element as if it were
    // submitted along with the rest of the form
    $_GET[$element['#name']]['file_path'] = $file->filepath;
  }
}