Video Field, a Drupal Module

/**
  * Implements hook_field_info().
  *
  * Provides the description of the field.
  */
 function video_field_field_info() {
  return array(
    // We name our field as the associative name of the array.
    'video_field_embed_url' => array(
      'label' => t('URL embed field'),
      'description' => t('Field to add an embed URL'),
      'default_widget' => 'video_field_text',
      'default_formatter' => 'video_field_simple_text',
    ),
  );
 }
 
/**
 * Implements hook_field_widget_info().
 *
 * @see video_field_field_widget_form()
 */
function video_field_field_widget_info() {
  return array(
    'video_field_text' => array(
      'label' => t('Textfield URL Embed'),
      'field types' => array('video_field_embed_url'),
    ),
  );
}
 
 /**
  * Implements hook_field_formatter_info().
  *
  *
  * @see video_field_field_formatter_view()
  */
 function video_field_field_formatter_info() {
  return array(
    // This formatter just displays the embed code
     'video_field_simple_text' => array(
      'label' => t('Simple text field for an embed URL'),
      'field types' => array('video_field_embed_url'),
    ),
  );
 }

function video_field_field_widget_form(&$form, &$form_state, $field, $instance, $langcode, $items, $delta, $element) {
  $value = isset($items[$delta]['embed_url']) ? $items[$delta]['embed_url'] : '';
 
  $widget = $element;
  $widget['#delta'] = $delta;
 
  switch ($instance['widget']['type']) {
 
    //define out embed field as a textfield and make sure the length is not more than 250 characters
    case 'video_field_text':
      $widget += array(
        '#type' => 'textfield',
        '#default_value' => $value,
        '#size' => 60,
        '#maxlength' => 250,
      );
      break;
  }
  $element['embed_url'] = $widget;
  return $element;
}

/**
 * Implements hook_field_validate().
 *
 * This hook gives us a chance to validate content that's in our
 * field. We're really only interested in the $items parameter, since
 * it holds arrays representing content in the field we've defined.
 * We want to verify that the items only contains an embed URL to a valid
 * video or web source, so we make a request to verify the video.  If the request 
 * returns anything else than 200 or 304 we add our own error notification 
 * to the $errors parameter.
 *
 * @see field_example_field_widget_error()
 */
function video_field_field_validate($entity_type, $entity, $field, $instance, $langcode, $items, &$errors) {
  foreach ($items as $delta => $item) {
    if (!empty($item['embed_url'])) {
        //make sure http:// is on the front of the URL to check for a valid source
        $result;
        if(strpos($item['embed_url'], 'http:') !== false){
           $result = drupal_http_request($item['embed_url']);
        }else{
           //add http: if it is not there
           $url = 'http:' . $item['embed_url'];
           $result = drupal_http_request($url);
        }
 
        if (in_array( $result->code, array(200, 304))) {
           // Use $result->data for the content
        }
        else {
          //build an error array to show the user
          $errors[$field['field_name']][$langcode][$delta][] = array(
             'error' => 'video_field_invalid',
             'message' => t('The embed URL must return a valid source'),
          );
        }
    }
  }
}
 
/**
 * Implements hook_field_widget_error().
 *
 * hook_field_widget_error() lets us figure out what to do with errors
 * we might have generated in hook_field_validate(). Generally, we'll just
 * call form_error().
 *
 * @see video_field_field_validate()
 * @see form_error()
 */
function video_field_field_widget_error($element, $error, $form, &$form_state) {
  switch ($error['error']) {
    case 'video_field_invalid':
      form_error($element, $error['message']);
      break;
  }
}
/**
 * Implements hook_field_is_empty().
 *
 * hook_field_is_emtpy() is where Drupal asks us if this field is empty.
 * Return TRUE if it does not contain data, FALSE if it does. This lets
 * the form API flag an error when required fields are empty.
 */
 function video_field_field_is_empty($item, $field) {
  return empty($item['embed_url']);
 }

 /**
  * Implements hook_field_formatter_view().
  *
  *
  * @see video_field_field_formatter_info()
  */
 function video_field_field_formatter_view($entity_type, $entity, $field, $instance, $langcode, $items, $display) {
  $element = array();
 
  switch ($display['type']) {
    // This formatter simply outputs the field as an iframe.
    case 'video_field_simple_text':
      foreach ($items as $delta => $item) {
        $element[$delta] = array(
          '#type' => 'html_tag',
          '#tag' => 'div',
          '#attributes' => array(
            'class' => 'video-field-iframe',
          ),
          '#value' => t('<div class="field field-video-field"><iframe src="'. $item['embed_url'] . '" frameborder="0" allowfullscreen=""></iframe></div>'),
        );
      }
      break;
  }
 
  return $element;
}