WP_Widget_Media
云策文档标注
概述
WP_Widget_Media 是 WordPress 核心中实现媒体小部件的抽象基类,继承自 WP_Widget。它提供了处理媒体附件、渲染前端内容和管理小部件实例的通用框架,支持音频、视频、图像和画廊等具体媒体小部件。
关键要点
- 抽象类,用于扩展创建特定媒体类型的小部件(如 WP_Widget_Media_Audio、WP_Widget_Media_Image)
- 包含核心方法:构造函数 __construct、注册钩子 _register_one、前端渲染 widget、表单处理 form 和更新 sanitize update
- 定义实例模式 get_instance_schema,用于验证和清理小部件数据,支持 REST API 集成
- 提供媒体状态过滤 display_media_state、脚本加载 enqueue_admin_scripts 和预览脚本 enqueue_preview_scripts
- 包含辅助方法:检查附件 MIME 类型 is_attachment_with_mime_type、清理令牌列表 sanitize_token_list
- 使用翻译标签数组 $l10n 和静态属性管理默认描述和本地化字符串
代码示例
abstract class WP_Widget_Media extends WP_Widget {
public $l10n = array(
'add_to_widget' => '',
'replace_media' => '',
// ... 其他翻译标签
);
protected $registered = false;
protected static $default_description = '';
protected static $l10n_defaults = array();
public function __construct( $id_base, $name, $widget_options = array(), $control_options = array() ) {
$widget_opts = wp_parse_args(
$widget_options,
array(
'description' => self::get_default_description(),
'customize_selective_refresh' => true,
'show_instance_in_rest' => true,
'mime_type' => '',
)
);
$control_opts = wp_parse_args( $control_options, array() );
$this->l10n = array_merge( self::get_l10n_defaults(), array_filter( $this->l10n ) );
parent::__construct( $id_base, $name, $widget_opts, $control_opts );
}
public function get_instance_schema() {
$schema = array(
'attachment_id' => array(
'type' => 'integer',
'default' => 0,
'minimum' => 0,
'description' => __( 'Attachment post ID' ),
'media_prop' => 'id',
),
'url' => array(
'type' => 'string',
'default' => '',
'format' => 'uri',
'description' => __( 'URL to the media file' ),
),
'title' => array(
'type' => 'string',
'default' => '',
'sanitize_callback' => 'sanitize_text_field',
'description' => __( 'Title for the widget' ),
'should_preview_update' => false,
),
);
$schema = apply_filters( "widget_{$this->id_base}_instance_schema", $schema, $this );
return $schema;
}
abstract public function render_media( $instance );
}注意事项
- WP_Widget_Media 是抽象类,不能直接实例化,必须通过子类实现 render_media 方法
- 小部件实例数据通过 get_instance_schema 定义模式,利用 REST API 函数进行验证和清理
- 在自定义器中,预览脚本需无条件加载以支持动态小部件添加和选择性刷新
- 翻译标签 $l10n 用于前端界面本地化,可通过过滤器或子类覆盖自定义
原文内容
Core class that implements a media widget.
Description
See also
Methods
| Name | Description |
|---|---|
| WP_Widget_Media::__construct | Constructor. |
| WP_Widget_Media::_register_one | Add hooks while registering all widget instances of this widget class. |
| WP_Widget_Media::display_media_state | Filters the default media display states for items in the Media list table. |
| WP_Widget_Media::enqueue_admin_scripts | Loads the required scripts and styles for the widget control. |
| WP_Widget_Media::enqueue_preview_scripts | Enqueue preview scripts. |
| WP_Widget_Media::form | Outputs the settings update form. |
| WP_Widget_Media::get_default_description | Returns the default description of the widget. |
| WP_Widget_Media::get_instance_schema | Get schema for properties of a widget instance (item). |
| WP_Widget_Media::get_l10n_defaults | Returns the default localized strings used by the widget. |
| WP_Widget_Media::has_content | Whether the widget has content to show. |
| WP_Widget_Media::is_attachment_with_mime_type | Determine if the supplied attachment is for a valid attachment post with the specified MIME type. |
| WP_Widget_Media::render_control_template_scripts | Render form template scripts. |
| WP_Widget_Media::render_media | Render the media on the frontend. |
| WP_Widget_Media::reset_default_labels | Resets the cache for the default labels. |
| WP_Widget_Media::sanitize_token_list | Sanitize a token list string, such as used in HTML rel and class attributes. |
| WP_Widget_Media::update | Sanitizes the widget form values as they are saved. |
| WP_Widget_Media::widget | Displays the widget on the front-end. |
Source
abstract class WP_Widget_Media extends WP_Widget {
/**
* Translation labels.
*
* @since 4.8.0
* @var array
*/
public $l10n = array(
'add_to_widget' => '',
'replace_media' => '',
'edit_media' => '',
'media_library_state_multi' => '',
'media_library_state_single' => '',
'missing_attachment' => '',
'no_media_selected' => '',
'add_media' => '',
);
/**
* Whether or not the widget has been registered yet.
*
* @since 4.8.1
* @var bool
*/
protected $registered = false;
/**
* The default widget description.
*
* @since 6.0.0
* @var string
*/
protected static $default_description = '';
/**
* The default localized strings used by the widget.
*
* @since 6.0.0
* @var string[]
*/
protected static $l10n_defaults = array();
/**
* Constructor.
*
* @since 4.8.0
*
* @param string $id_base Base ID for the widget, lowercase and unique.
* @param string $name Name for the widget displayed on the configuration page.
* @param array $widget_options Optional. Widget options. See wp_register_sidebar_widget() for
* information on accepted arguments. Default empty array.
* @param array $control_options Optional. Widget control options. See wp_register_widget_control()
* for information on accepted arguments. Default empty array.
*/
public function __construct( $id_base, $name, $widget_options = array(), $control_options = array() ) {
$widget_opts = wp_parse_args(
$widget_options,
array(
'description' => self::get_default_description(),
'customize_selective_refresh' => true,
'show_instance_in_rest' => true,
'mime_type' => '',
)
);
$control_opts = wp_parse_args( $control_options, array() );
$this->l10n = array_merge( self::get_l10n_defaults(), array_filter( $this->l10n ) );
parent::__construct(
$id_base,
$name,
$widget_opts,
$control_opts
);
}
/**
* Add hooks while registering all widget instances of this widget class.
*
* @since 4.8.0
*
* @param int $number Optional. The unique order number of this widget instance
* compared to other instances of the same class. Default -1.
*/
public function _register_one( $number = -1 ) {
parent::_register_one( $number );
if ( $this->registered ) {
return;
}
$this->registered = true;
/*
* Note that the widgets component in the customizer will also do
* the 'admin_print_scripts-widgets.php' action in WP_Customize_Widgets::print_scripts().
*/
add_action( 'admin_print_scripts-widgets.php', array( $this, 'enqueue_admin_scripts' ) );
if ( $this->is_preview() ) {
add_action( 'wp_enqueue_scripts', array( $this, 'enqueue_preview_scripts' ) );
}
/*
* Note that the widgets component in the customizer will also do
* the 'admin_footer-widgets.php' action in WP_Customize_Widgets::print_footer_scripts().
*/
add_action( 'admin_footer-widgets.php', array( $this, 'render_control_template_scripts' ) );
add_filter( 'display_media_states', array( $this, 'display_media_state' ), 10, 2 );
}
/**
* Get schema for properties of a widget instance (item).
*
* @since 4.8.0
*
* @see WP_REST_Controller::get_item_schema()
* @see WP_REST_Controller::get_additional_fields()
* @link https://core.trac.wordpress.org/ticket/35574
*
* @return array Schema for properties.
*/
public function get_instance_schema() {
$schema = array(
'attachment_id' => array(
'type' => 'integer',
'default' => 0,
'minimum' => 0,
'description' => __( 'Attachment post ID' ),
'media_prop' => 'id',
),
'url' => array(
'type' => 'string',
'default' => '',
'format' => 'uri',
'description' => __( 'URL to the media file' ),
),
'title' => array(
'type' => 'string',
'default' => '',
'sanitize_callback' => 'sanitize_text_field',
'description' => __( 'Title for the widget' ),
'should_preview_update' => false,
),
);
/**
* Filters the media widget instance schema to add additional properties.
*
* @since 4.9.0
*
* @param array $schema Instance schema.
* @param WP_Widget_Media $widget Widget object.
*/
$schema = apply_filters( "widget_{$this->id_base}_instance_schema", $schema, $this );
return $schema;
}
/**
* Determine if the supplied attachment is for a valid attachment post with the specified MIME type.
*
* @since 4.8.0
*
* @param int|WP_Post $attachment Attachment post ID or object.
* @param string $mime_type MIME type.
* @return bool Is matching MIME type.
*/
public function is_attachment_with_mime_type( $attachment, $mime_type ) {
if ( empty( $attachment ) ) {
return false;
}
$attachment = get_post( $attachment );
if ( ! $attachment ) {
return false;
}
if ( 'attachment' !== $attachment->post_type ) {
return false;
}
return wp_attachment_is( $mime_type, $attachment );
}
/**
* Sanitize a token list string, such as used in HTML rel and class attributes.
*
* @since 4.8.0
*
* @link http://w3c.github.io/html/infrastructure.html#space-separated-tokens
* @link https://developer.mozilla.org/en-US/docs/Web/API/DOMTokenList
* @param string|array $tokens List of tokens separated by spaces, or an array of tokens.
* @return string Sanitized token string list.
*/
public function sanitize_token_list( $tokens ) {
if ( is_string( $tokens ) ) {
$tokens = preg_split( '/s+/', trim( $tokens ) );
}
$tokens = array_map( 'sanitize_html_class', $tokens );
$tokens = array_filter( $tokens );
return implode( ' ', $tokens );
}
/**
* Displays the widget on the front-end.
*
* @since 4.8.0
*
* @see WP_Widget::widget()
*
* @param array $args Display arguments including before_title, after_title, before_widget, and after_widget.
* @param array $instance Saved setting from the database.
*/
public function widget( $args, $instance ) {
$instance = wp_parse_args( $instance, wp_list_pluck( $this->get_instance_schema(), 'default' ) );
// Short-circuit if no media is selected.
if ( ! $this->has_content( $instance ) ) {
return;
}
echo $args['before_widget'];
/** This filter is documented in wp-includes/widgets/class-wp-widget-pages.php */
$title = apply_filters( 'widget_title', $instance['title'], $instance, $this->id_base );
if ( $title ) {
echo $args['before_title'] . $title . $args['after_title'];
}
/**
* Filters the media widget instance prior to rendering the media.
*
* @since 4.8.0
*
* @param array $instance Instance data.
* @param array $args Widget args.
* @param WP_Widget_Media $widget Widget object.
*/
$instance = apply_filters( "widget_{$this->id_base}_instance", $instance, $args, $this );
$this->render_media( $instance );
echo $args['after_widget'];
}
/**
* Sanitizes the widget form values as they are saved.
*
* @since 4.8.0
* @since 5.9.0 Renamed `$instance` to `$old_instance` to match parent class
* for PHP 8 named parameter support.
*
* @see WP_Widget::update()
* @see WP_REST_Request::has_valid_params()
* @see WP_REST_Request::sanitize_params()
*
* @param array $new_instance Values just sent to be saved.
* @param array $old_instance Previously saved values from database.
* @return array Updated safe values to be saved.
*/
public function update( $new_instance, $old_instance ) {
$schema = $this->get_instance_schema();
foreach ( $schema as $field => $field_schema ) {
if ( ! array_key_exists( $field, $new_instance ) ) {
continue;
}
$value = $new_instance[ $field ];
/*
* Workaround for rest_validate_value_from_schema() due to the fact that
* rest_is_boolean( '' ) === false, while rest_is_boolean( '1' ) is true.
*/
if ( 'boolean' === $field_schema['type'] && '' === $value ) {
$value = false;
}
if ( true !== rest_validate_value_from_schema( $value, $field_schema, $field ) ) {
continue;
}
$value = rest_sanitize_value_from_schema( $value, $field_schema );
// @codeCoverageIgnoreStart
if ( is_wp_error( $value ) ) {
continue; // Handle case when rest_sanitize_value_from_schema() ever returns WP_Error as its phpdoc @return tag indicates.
}
// @codeCoverageIgnoreEnd
if ( isset( $field_schema['sanitize_callback'] ) ) {
$value = call_user_func( $field_schema['sanitize_callback'], $value );
}
if ( is_wp_error( $value ) ) {
continue;
}
$old_instance[ $field ] = $value;
}
return $old_instance;
}
/**
* Render the media on the frontend.
*
* @since 4.8.0
*
* @param array $instance Widget instance props.
*/
abstract public function render_media( $instance );
/**
* Outputs the settings update form.
*
* Note that the widget UI itself is rendered with JavaScript via `MediaWidgetControl#render()`.
*
* @since 4.8.0
*
* @see WP_Widget_Media::render_control_template_scripts() Where the JS template is located.
*
* @param array $instance Current settings.
*/
final public function form( $instance ) {
$instance_schema = $this->get_instance_schema();
$instance = wp_array_slice_assoc(
wp_parse_args( (array) $instance, wp_list_pluck( $instance_schema, 'default' ) ),
array_keys( $instance_schema )
);
foreach ( $instance as $name => $value ) : ?>
<input
type="hidden"
data-property="<?php echo esc_attr( $name ); ?>"
class="media-widget-instance-property"
name="<?php echo esc_attr( $this->get_field_name( $name ) ); ?>"
id="<?php echo esc_attr( $this->get_field_id( $name ) ); // Needed specifically by wpWidgets.appendTitle(). ?>"
value="<?php echo esc_attr( is_array( $value ) ? implode( ',', $value ) : (string) $value ); ?>"
/>
get_settings() as $instance ) {
if ( isset( $instance['attachment_id'] ) && $instance['attachment_id'] === $post->ID ) {
++$use_count;
}
}
if ( 1 === $use_count ) {
$states[] = $this->l10n['media_library_state_single'];
} elseif ( $use_count > 0 ) {
$states[] = sprintf( translate_nooped_plural( $this->l10n['media_library_state_multi'], $use_count ), number_format_i18n( $use_count ) );
}
return $states;
}
/**
* Enqueue preview scripts.
*
* These scripts normally are enqueued just-in-time when a widget is rendered.
* In the customizer, however, widgets can be dynamically added and rendered via
* selective refresh, and so it is important to unconditionally enqueue them in
* case a widget does get added.
*
* @since 4.8.0
*/
public function enqueue_preview_scripts() {}
/**
* Loads the required scripts and styles for the widget control.
*
* @since 4.8.0
*/
public function enqueue_admin_scripts() {
wp_enqueue_media();
wp_enqueue_script( 'media-widgets' );
}
/**
* Render form template scripts.
*
* @since 4.8.0
*/
public function render_control_template_scripts() {
?>
<script type="text/html" id="tmpl-widget-media-<?php echo esc_attr( $this->id_base ); ?>-control"></script>
__( 'No media selected' ),
'add_media' => _x( 'Add Media', 'label for button in the media widget' ),
'replace_media' => _x( 'Replace Media', 'label for button in the media widget; should preferably not be longer than ~13 characters long' ),
'edit_media' => _x( 'Edit Media', 'label for button in the media widget; should preferably not be longer than ~13 characters long' ),
'add_to_widget' => __( 'Add to Widget' ),
'missing_attachment' => sprintf(
/* translators: %s: URL to media library. */
__( 'That file cannot be found. Check your <a href="%s">media library</a> and make sure it was not deleted.' ),
esc_url( admin_url( 'upload.php' ) )
),
/* translators: %d: Widget count. */
'media_library_state_multi' => _n_noop( 'Media Widget (%d)', 'Media Widget (%d)' ),
'media_library_state_single' => __( 'Media Widget' ),
'unsupported_file_type' => __( 'Looks like this is not the correct kind of file. Please link to an appropriate file instead.' ),
);
return self::$l10n_defaults;
}
}
Changelog
| Version | Description |
|---|---|
| 4.8.0 | Introduced. |