我正在构建一个自定义字段模块来与我们的流媒体视频提供商合作。作为其中的一部分，我需要从提供商的 API 中获取基于所选类别的视频。该字段将需要存储许多部分 - 选定的类别、选定的视频和一些尚未添加的附加详细信息（例如标题）。
我可以让这个表单出现在节点编辑页面上（在将字段附加到内容类型之后），但它似乎没有保存用户的输入。这是编辑节点屏幕上的表单：节点编辑屏幕上的字段。用户的工作流程是他们选择一个类别，该类别填充要选择的视频列表。当他们选择视频时，他们会在 $element['teacherstv']['teacherstv_video_details'] 中看到预览。这一直有效，直到用户保存表单。此时，所选值将丢失。
我查看了 D7 的 Field API 和 Forms API 文档，但看不到任何关于如何设置这种字段小部件并让它保存用户输入的明确说明。
这是 hook_field_widget_form() 的代码
function teacherstv_field_widget_form(&$form, &$form_state, $field, $instance, $langcode, $items, $delta, $element) {
// $value = $isset($items[$delta['teacherstv']) ? $items[$delta]['teacherstv'] : '';
$widget['#delta'] = $delta;
//lets get an array of our categories from core
$coreapi = new coreapi();
$APIsettings = variable_get('teacherstv_API_settings');
$coreapi->apiuser = $APIsettings['username'];
$coreapi->apipwd = $APIsettings['password'];
$coreapi->apiurl = $APIsettings['api_url'];
$coreapi->sortcriteria = "alpha";
//$categoriesavailable = $coreapi->get_categories();
$categories = coreapi_get_categories();
$defaults = $field['settings'];
$settings = $instance['settings'];
$category = !is_null($form_state['values'][$field['field_name']]['und'][$delta]['teacherstv']['teacherstv_category']) ? $form_state['values'][$field['field_name']]['und'][$delta]['teacherstv']['teacherstv_category'] : $defaults['teacherstv']['defaultcategory'];
switch ($instance['widget']['type']) {
case 'teacherstv':
$element['teacherstv'] = array(
'#tree' => TRUE,
'#type' => 'fieldset',
'#title' => t('TeachersTV Video'),
'#description' => '<p>' . t('Select a video from the TeachersTV service to embed.') . '</p>',
'#delta' => $delta,
);
$element['teacherstv']['teacherstv_category'] = array(
'#type' => 'select',
'#field_parents' => 'teacherstv',
'#title' => t('Video Categories'),
'#options' => $categories,
'#description' => t('Select a video category for a list of videos'),
'#default_value' => !is_null($settings['teacherstv_category']) ? array($settings['teacherstv_category']) : array($category),
'#ajax' => array(
'callback' => 'teacherstv_ajax_videolist',
'wrapper' => 'teacherstv-videolist-' . $delta . '-div',
'method' => 'replace',
),
'#delta' => $delta,
);
$videos = coreapi_list_videos($category);
$videos[0] = "--Please select a video--";
asort($videos);
$element['teacherstv']['teacherstv_video'] = array(
'#type' => 'select',
'#title' => t('Select a video'),
'#field_parents' => 'teacherstv',
'#prefix' => '<div id="teacherstv-videolist-' . $delta . '-div">',
'#suffix' => '</div>',
'#options' => array(0 => 'Video 1'),
'#default_value' =>
isset($form_state['values'][$field['field_name']]['und'][$delta]['teacherstv']['teacherstv_video']) ? $form_state['values'][$field['field_name']]['und'][$delta]['teacherstv']['teacherstv_video'] : NULL,
'#description' => t('Select a video.'),
'#options' => $videos,
'#ajax' => array(
'callback' => 'teacherstv_ajax_videoselect',
'wrapper' => 'teacherstv-videodetails-' . $delta . '-div',
),
'#delta' => $delta,
);
$video_keys = array_keys($videos);
$selected_video = isset($form_state['values'][$field['field_name']]['und'][$delta]['teacherstv_category']) ? $form_state['values'][$field['field_name']]['und'][$delta]['teacherstv_category'] : NULL;
$element['teacherstv']['teacherstv_video_details'] = array(
'#type' => 'markup',
'#field_parents' => 'teacherstv',
'#title' => t('Video details'),
'#prefix' => '<div id="teacherstv-videodetails-' . $delta . '-div">',
'#suffix' => '</div>',
'#description' => t('Details about the video.'),
'#markup' => teacherstv_ajax_render_video($selected_video),
'#delta' => $delta,
);
break;
}
return $element;
}