hook_field_extra_fields：默认隐藏

在实现hook_field_extra_fields（）时，是否可以默认隐藏额外的字段？

有时，提供额外的字段作为选项比较好，而不是在启用模块后立即显示它。

在_field_info_prepare_extra_fields()默认情况下，多余的字段设置为可见，但是多余的字段设置存储在field_bundle_settings变量中，您可以在模块中进行更改，hook_install()例如：

$entity_type = 'node';
$bundle = 'article';
$field_name = 'my_extra_field';
$view_mode = 'teaser';

$field_bundle_setting = variable_get('field_bundle_settings', array());
$field_bundle_setting[$entity_type][$bundle]['extra_fields']['display'][$field_name][$view_mode]['visible'] = FALSE;
variable_set('field_bundle_settings', $field_bundle_setting);

_field_extra_fields_pre_render（）是field_attach_form（）和field_attach_view（）使用的渲染前回调，包含以下代码：

  elseif (isset($elements['#view_mode'])) {
    $view_mode = $elements['#view_mode'];
    $extra_fields = field_extra_fields_get_display($entity_type, $bundle, $view_mode);
    foreach ($extra_fields as $name => $settings) {
      if (isset($elements[$name])) {
        $elements[$name]['#weight'] = $settings['weight'];
        // Visibility: make sure we do not accidentally show a hidden element.
        $elements[$name]['#access'] = isset($elements[$name]['#access']) ? ($elements[$name]['#access'] && $settings['visible']) : $settings['visible'];
      }
    }
  }

实现hook_field_extra_fields_display_alter（），您可以更改可见性设置，但是这会使字段在显示表单的所有时间中都不可见。如果不想在第一次加载表单时显示该字段，而在例如选择另一个表单字段或更改其值时显示该字段，则需要使用一些JavaScript代码。

function mymodule_field_extra_fields_display_alter(&$displays, $context) {
  if ($context['entity_type'] == 'taxonomy_term' && $context['view_mode'] == 'full') {
    $displays['description']['visible'] = FALSE;
  }
}

有一个补丁程序可以将此功能添加到drupal核心。

如果您想查看此内容，请对其进行审核并提供反馈。

http://drupal.org/node/1256368#comment-7201552

在模块的安装挂钩中，您可以调用与此函数类似的函数，默认情况下它将批量隐藏您的多余字段。

/**
 * Sets default visibility of extra fields in all active view modes on entity bundles.
 *
 * This will not overwrite visibility that already exists in the variable.
 *
 * @param  array $extra_field_names An array of extra fields
 * @param  string $entity_type       The name of the entity type. Defaults to 'node'.
 * @param  array $bundles           An array of bundle objects or names.
 */
function my_module_hide_extra_fields($extra_field_names, $entity_type = 'node', $bundles = NULL) {
  $entity_info = entity_get_info($entity_type);
  if ($bundles === NULL) {
    $bundles = array_keys($entity_info['bundles']);
  }

  foreach ($bundles as $bundle) {
    if (!is_string($bundle)) {
      $bundle = $bundle->type;
    }
    $settings = field_bundle_settings($entity_type, $bundle);

    $active_modes = array('default');
    foreach ($settings['view_modes'] as $mode => $mode_settings) {
      if ($mode_settings['custom_settings']) {
        $active_modes[] = $mode;
      }
    }
    foreach ($extra_field_names as $field_name) {
      foreach ($active_modes as $mode) {
        if (empty($settings['extra_fields']['display'][$field_name][$mode])
          || !array_key_exists('visible', $settings['extra_fields']['display'][$field_name][$mode])) {
          $settings['extra_fields']['display'][$field_name][$mode]['visible'] = FALSE;
          $settings['extra_fields']['display'][$field_name][$mode] += array(
            'weight' => 0, 
          );
        }
      }
    }
    field_bundle_settings($entity_type, $bundle, $settings);
  }
}

如此简单的例子。对于Drupal 7，在example_module目录下创建example_module.install

/**
 * hook_install
 */

function example_module_install() {
  $field_machine_name = 'new_extra_field';
  $entity_types = array('node', 'taxonomy_term', 'user'); 
  foreach ($entity_types as $type) {
    $info = entity_get_info($type);
    $settings = field_bundle_settings($type, $bundle);
    $view_modes = array_merge(array('default'), array_keys($info['view modes']));
    foreach($view_modes as $view_mode) {
      $settings['extra_fields']['display'][$field_machine_name][$view_mode] = array(
        'visible' => FALSE,
        'weight'  => 0,
      );
    }
    field_bundle_settings($type, $bundle, $settings);
  }
}

hook_install的文档 https://api.drupal.org/api/drupal/modules%21system%21system.api.php/function/hook_install/7

在您的example_module.module文件中添加

 /**
  * Implementation of hook_field_extra_fields
  *
  */
 function example_module_field_extra_fields() {
   $extra = array();
   $field_machine_name = 'new_extra_field';
   $entity_types = array('node', 'taxonomy_term', 'user'); 
   foreach ($entity_types as $type) {
     $info = entity_get_info($type);
     foreach(array_keys($info["bundles"]) as $bundle) {
       $extra[$type][$bundle]['display'][$field_machine_name] = array(
         'label' => t('New extra field that will show up in manage display'),
         'description' => 'A description for the extra field',
         'weight' => 5,
        );
     }
   }
   return $extra; 
 }

hook_field_extra_fields的文档https://api.drupal.org/api/drupal/modules%21field%21field.api.php/function/hook_field_extra_fields/7