文章目录
WordPress函数dynamic_sidebar()函数显示动态侧边栏
在 WordPress CMS内容管理系统中，dynamic_sidebar()是 WordPress 中一个非常有用的函数，dynamic_sidebar() 是 WordPress 中用于显示动态侧边栏的函数。这个函数允许主题开发者在模板文件中指定一个位置来显示小工具（widgets）
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dynamic_sidebar()函数基本语法
描述
显示动态侧边栏
用法
if (is_active_sidebar('left-sidebar')) {
echo '<ul id="sidebar">';
dynamic_sidebar('left-sidebar');
echo '</ul>';
}- $index (int|string，可选)：此参数用于指定动态侧边栏的索引、名称或 ID。默认值为 1。
dynamic_sidebar()函数
在 WordPress 中，该dynamic_sidebar()函数通常在没有 sidebar.php 文件可供查询或使用可能没有模板的侧边栏时用作回调。它还可用于呈现主题的 register_sidebar(array($arguments)) 函数中可能生成的动态侧边栏。（源文件可参考这里）
function dynamic_sidebar( $index = 1 ) {
global $wp_registered_sidebars, $wp_registered_widgets;
if ( is_int( $index ) ) {
$index = "sidebar-$index";
} else {
$index = sanitize_title( $index );
foreach ( (array) $wp_registered_sidebars as $key => $value ) {
if ( sanitize_title( $value['name'] ) === $index ) {
$index = $key;
break;
}
}
}
$sidebars_widgets = wp_get_sidebars_widgets();
if ( empty( $wp_registered_sidebars[ $index ] ) || empty( $sidebars_widgets[ $index ] ) || ! is_array( $sidebars_widgets[ $index ] ) ) {
/** This action is documented in wp-includes/widget.php */
do_action( 'dynamic_sidebar_before', $index, false );
/** This action is documented in wp-includes/widget.php */
do_action( 'dynamic_sidebar_after', $index, false );
/** This filter is documented in wp-includes/widget.php */
return apply_filters( 'dynamic_sidebar_has_widgets', false, $index );
}
$sidebar = $wp_registered_sidebars[ $index ];
$sidebar['before_sidebar'] = sprintf( $sidebar['before_sidebar'], $sidebar['id'], $sidebar['class'] );
/**
* Fires before widgets are rendered in a dynamic sidebar.
*
* Note: The action also fires for empty sidebars, and on both the front end
* and back end, including the Inactive Widgets sidebar on the Widgets screen.
*
* @since 3.9.0
*
* @param int|string $index Index, name, or ID of the dynamic sidebar.
* @param bool $has_widgets Whether the sidebar is populated with widgets.
* Default true.
*/
do_action( 'dynamic_sidebar_before', $index, true );
if ( ! is_admin() && ! empty( $sidebar['before_sidebar'] ) ) {
echo $sidebar['before_sidebar'];
}
$did_one = false;
foreach ( (array) $sidebars_widgets[ $index ] as $id ) {
if ( ! isset( $wp_registered_widgets[ $id ] ) ) {
continue;
}
$params = array_merge(
array(
array_merge(
$sidebar,
array(
'widget_id' => $id,
'widget_name' => $wp_registered_widgets[ $id ]['name'],
)
),
),
(array) $wp_registered_widgets[ $id ]['params']
);
// Substitute HTML `id` and `class` attributes into `before_widget`.
$classname_ = '';
foreach ( (array) $wp_registered_widgets[ $id ]['classname'] as $cn ) {
if ( is_string( $cn ) ) {
$classname_ .= '_' . $cn;
} elseif ( is_object( $cn ) ) {
$classname_ .= '_' . get_class( $cn );
}
}
$classname_ = ltrim( $classname_, '_' );
$params[0]['before_widget'] = sprintf(
$params[0]['before_widget'],
str_replace( '\\', '_', $id ),
$classname_
);
/**
* Filters the parameters passed to a widget's display callback.
*
* Note: The filter is evaluated on both the front end and back end,
* including for the Inactive Widgets sidebar on the Widgets screen.
*
* @since 2.5.0
*
* @see register_sidebar()
*
* @param array $params {
* @type array $args {
* An array of widget display arguments.
*
* @type string $name Name of the sidebar the widget is assigned to.
* @type string $id ID of the sidebar the widget is assigned to.
* @type string $description The sidebar description.
* @type string $class CSS class applied to the sidebar container.
* @type string $before_widget HTML markup to prepend to each widget in the sidebar.
* @type string $after_widget HTML markup to append to each widget in the sidebar.
* @type string $before_title HTML markup to prepend to the widget title when displayed.
* @type string $after_title HTML markup to append to the widget title when displayed.
* @type string $widget_id ID of the widget.
* @type string $widget_name Name of the widget.
* }
* @type array $widget_args {
* An array of multi-widget arguments.
*
* @type int $number Number increment used for multiples of the same widget.
* }
* }
*/
$params = apply_filters( 'dynamic_sidebar_params', $params );
$callback = $wp_registered_widgets[ $id ]['callback'];
/**
* Fires before a widget's display callback is called.
*
* Note: The action fires on both the front end and back end, including
* for widgets in the Inactive Widgets sidebar on the Widgets screen.
*
* The action is not fired for empty sidebars.
*
* @since 3.0.0
*
* @param array $widget {
* An associative array of widget arguments.
*
* @type string $name Name of the widget.
* @type string $id Widget ID.
* @type callable $callback When the hook is fired on the front end, `$callback` is an array
* containing the widget object. Fired on the back end, `$callback`
* is 'wp_widget_control', see `$_callback`.
* @type array $params An associative array of multi-widget arguments.
* @type string $classname CSS class applied to the widget container.
* @type string $description The widget description.
* @type array $_callback When the hook is fired on the back end, `$_callback` is populated
* with an array containing the widget object, see `$callback`.
* }
*/
do_action( 'dynamic_sidebar', $wp_registered_widgets[ $id ] );
if ( is_callable( $callback ) ) {
call_user_func_array( $callback, $params );
$did_one = true;
}
}
if ( ! is_admin() && ! empty( $sidebar['after_sidebar'] ) ) {
echo $sidebar['after_sidebar'];
}
/**
* Fires after widgets are rendered in a dynamic sidebar.
*
* Note: The action also fires for empty sidebars, and on both the front end
* and back end, including the Inactive Widgets sidebar on the Widgets screen.
*
* @since 3.9.0
*
* @param int|string $index Index, name, or ID of the dynamic sidebar.
* @param bool $has_widgets Whether the sidebar is populated with widgets.
* Default true.
*/
do_action( 'dynamic_sidebar_after', $index, true );
/**
* Filters whether a sidebar has widgets.
*
* Note: The filter is also evaluated for empty sidebars, and on both the front end
* and back end, including the Inactive Widgets sidebar on the Widgets screen.
*
* @since 3.9.0
*
* @param bool $did_one Whether at least one widget was rendered in the sidebar.
* Default false.
* @param int|string $index Index, name, or ID of the dynamic sidebar.
*/
return apply_filters( 'dynamic_sidebar_has_widgets', $did_one, $index );
}
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如何使用dynamic_sidebar()
显示右侧边栏，显示右侧边栏的方法如下：
echo '<ul id="sidebar">';
dynamic_sidebar('right-sidebar');
echo '</ul>';显示带后备功能的默认侧边栏，当没有侧边栏处于活动状态时，显示具有静态后备的默认侧边栏：
echo '<ul id="sidebar">';
if (!dynamic_sidebar()) {
echo '<li>{static sidebar item 1}</li>';
echo '<li>{static sidebar item 2}</li>';
}
echo '</ul>';使用条件语句如果管理员尚未为小部件分配侧边栏，则使用PHP条件语句安全地呈现动态侧边栏并提供上下文：
echo '<section id="sidebar">';
if (is_active_sidebar('sidebar')) {
dynamic_sidebar('sidebar');
} else {
echo '<div class="meta-default">';
the_widget('WP_Widget_Categories', '', '');
get_search_form();
echo '<nav class="sidebar-login">';
echo '<ul>';
wp_loginout();
echo '</ul></nav></div>';
}
echo '</section>';显示具有指定数字索引的侧边栏要显示具有指定数字索引的侧边栏，您可以执行以下操作：
dynamic_sidebar(2); // Displays the second registered sidebar显示前检查侧边栏是否处于活动状态在显示侧边栏之前，最好先检查一下它是否处于活动状态：这有助于防止页面上出现空的div部分，从而可能产生空白空间或页面视图对齐破坏。
if (is_active_sidebar('my_sidebar')) {
dynamic_sidebar('my_sidebar');
}晓得博客，版权所有丨如未注明，均为原创
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