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WP_Widget_Meta

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概述

WP_Widget_Meta 是 WordPress 核心类，用于实现 Meta 小工具，显示登录/登出、RSS 链接等内容。它继承自 WP_Widget，提供小工具的基本功能。

关键要点

  • WP_Widget_Meta 是一个核心小工具类，用于显示 Meta 相关链接，如登录、RSS 和 WordPress.org 链接。
  • 类继承自 WP_Widget，遵循 WordPress 小工具的标准结构，包括构造方法、widget、update 和 form 方法。
  • widget 方法输出小工具内容，支持 HTML5 和 XHTML 格式，并应用过滤器如 widget_title 和 navigation_widgets_format。
  • update 方法处理设置更新，对标题进行 sanitize_text_field 清理。
  • form 方法输出设置表单，使用 wp_parse_args 处理默认值。

代码示例

class WP_Widget_Meta extends WP_Widget {
    public function __construct() {
        $widget_ops = array(
            'classname'                   => 'widget_meta',
            'description'                 => __( 'Login, RSS, & WordPress.org links.' ),
            'customize_selective_refresh' => true,
            'show_instance_in_rest'       => true,
        );
        parent::__construct( 'meta', __( 'Meta' ), $widget_ops );
    }

    public function widget( $args, $instance ) {
        $default_title = __( 'Meta' );
        $title         = ! empty( $instance['title'] ) ? $instance['title'] : $default_title;
        $title = apply_filters( 'widget_title', $title, $instance, $this->id_base );
        echo $args['before_widget'];
        if ( $title ) {
            echo $args['before_title'] . $title . $args['after_title'];
        }
        $format = current_theme_supports( 'html5', 'navigation-widgets' ) ? 'html5' : 'xhtml';
        $format = apply_filters( 'navigation_widgets_format', $format );
        if ( 'html5' === $format ) {
            $title      = trim( strip_tags( $title ) );
            $aria_label = $title ? $title : $default_title;
            echo '';
        }
        ?>
        <ul>
            <?php wp_register(); ?>
            <li><?php wp_loginout(); ?></li>
            <li><a href="<?php echo esc_url( get_bloginfo( 'rss2_url' ) ); ?>"><?php _e( 'Entries feed' ); ?></a></li>
            <li><a href="<?php echo esc_url( get_bloginfo( 'comments_rss2_url' ) ); ?>"><?php _e( 'Comments feed' ); ?></a></li>
            <?php
            echo apply_filters(
                'widget_meta_poweredby',
                sprintf(
                    '<li><a href="%1$s">%2$s</a></li>',
                    esc_url( __( 'https://wordpress.org/' ) ),
                    __( 'WordPress.org' )
                ),
                $instance
            );
            wp_meta();
            ?>
        </ul>
        <?php
        if ( 'html5' === $format ) {
            echo '';
        }
        echo $args['after_widget'];
    }

    public function update( $new_instance, $old_instance ) {
        $instance          = $old_instance;
        $instance['title'] = sanitize_text_field( $new_instance['title'] );
        return $instance;
    }

    public function form( $instance ) {
        $instance = wp_parse_args( (array) $instance, array( 'title' => '' ) );
        ?>
        <p>
            <label for="<?php echo $this->get_field_id( 'title' ); ?>"><?php _e( 'Title:' ); ?></label>
            <input class="widefat" id="<?php echo $this->get_field_id( 'title' ); ?>" name="<?php echo $this->get_field_name( 'title' ); ?>" type="text" value="<?php echo esc_attr( $instance['title'] ); ?>" />
        </p>
        <?php
    }
}

注意事项

  • WP_Widget_Meta 自 WordPress 2.8.0 引入，是核心小工具的一部分，不应直接修改，可通过子类或过滤器自定义。
  • widget 方法中使用了多个过滤器，如 widget_title 和 navigation_widgets_format，开发者可以利用这些过滤器调整输出。
  • update 方法仅处理标题字段，确保数据安全，其他设置需根据需求扩展。
  • form 方法使用 wp_parse_args 确保实例设置具有默认值，避免未定义错误。
📄 原文内容

Core class used to implement a Meta widget.

Description

Displays log in/out, RSS feed links, etc.

See also

Methods

Name Description
WP_Widget_Meta::__construct Sets up a new Meta widget instance.
WP_Widget_Meta::form Outputs the settings form for the Meta widget.
WP_Widget_Meta::update Handles updating settings for the current Meta widget instance.
WP_Widget_Meta::widget Outputs the content for the current Meta widget instance.

Source

class WP_Widget_Meta extends WP_Widget {


	/**

	 * Sets up a new Meta widget instance.

	 *

	 * @since 2.8.0

	 */

	public function __construct() {

		$widget_ops = array(

			'classname'                   => 'widget_meta',

			'description'                 => __( 'Login, RSS, & WordPress.org links.' ),

			'customize_selective_refresh' => true,

			'show_instance_in_rest'       => true,

		);

		parent::__construct( 'meta', __( 'Meta' ), $widget_ops );

	}


	/**

	 * Outputs the content for the current Meta widget instance.

	 *

	 * @since 2.8.0

	 *

	 * @param array $args     Display arguments including 'before_title', 'after_title',

	 *                        'before_widget', and 'after_widget'.

	 * @param array $instance Settings for the current Meta widget instance.

	 */

	public function widget( $args, $instance ) {

		$default_title = __( 'Meta' );

		$title         = ! empty( $instance['title'] ) ? $instance['title'] : $default_title;


		/** This filter is documented in wp-includes/widgets/class-wp-widget-pages.php */

		$title = apply_filters( 'widget_title', $title, $instance, $this->id_base );


		echo $args['before_widget'];


		if ( $title ) {

			echo $args['before_title'] . $title . $args['after_title'];

		}


		$format = current_theme_supports( 'html5', 'navigation-widgets' ) ? 'html5' : 'xhtml';


		/** This filter is documented in wp-includes/widgets/class-wp-nav-menu-widget.php */

		$format = apply_filters( 'navigation_widgets_format', $format );


		if ( 'html5' === $format ) {

			// The title may be filtered: Strip out HTML and make sure the aria-label is never empty.

			$title      = trim( strip_tags( $title ) );

			$aria_label = $title ? $title : $default_title;

			echo '<nav aria-label="' . esc_attr( $aria_label ) . '">';

		}

		?>


		<ul>


			<li></li>

			<li><a href="<?php echo esc_url( get_bloginfo( 'rss2_url' ) ); ?>"></a></li>

			<li><a href="<?php echo esc_url( get_bloginfo( 'comments_rss2_url' ) ); ?>"></a></li>


			<a href="%1$s">%2$s</a></li>',

					esc_url( __( 'https://wordpress.org/' ) ),

					__( 'WordPress.org' )

				),

				$instance

			);


			wp_meta();

			?>


		</ul>


		';

		}


		echo $args['after_widget'];

	}


	/**

	 * Handles updating settings for the current Meta widget instance.

	 *

	 * @since 2.8.0

	 *

	 * @param array $new_instance New settings for this instance as input by the user via

	 *                            WP_Widget::form().

	 * @param array $old_instance Old settings for this instance.

	 * @return array Updated settings to save.

	 */

	public function update( $new_instance, $old_instance ) {

		$instance          = $old_instance;

		$instance['title'] = sanitize_text_field( $new_instance['title'] );


		return $instance;

	}


	/**

	 * Outputs the settings form for the Meta widget.

	 *

	 * @since 2.8.0

	 *

	 * @param array $instance Current settings.

	 */

	public function form( $instance ) {

		$instance = wp_parse_args( (array) $instance, array( 'title' => '' ) );

		?>

		<p>

			<label for="<?php echo $this->get_field_id( 'title' ); ?>"></label>

			<input class="widefat" id="<?php echo $this->get_field_id( 'title' ); ?>" name="<?php echo $this->get_field_name( 'title' ); ?>" type="text" value="<?php echo esc_attr( $instance['title'] ); ?>" />

		</p>

		</pre><p class="wporg-dot-link-list"><a href="https://developer.wordpress.org/reference/files/wp-includes/widgets/class-wp-widget-meta.php/">View all references</a> <a href="https://core.trac.wordpress.org/browser/tags/6.9.4/src/wp-includes/widgets/class-wp-widget-meta.php#L19">View on Trac</a> <a href="https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/widgets/class-wp-widget-meta.php#L19-L143">View on GitHub</a></p></section>


		<section class="wp-block-wporg-code-reference-related" data-nosnippet="true"><h2 id="related" class="is-toc-heading wp-block-heading has-heading-5-font-size" tabindex="-1" ><a href="#related">Related</a></h2> <section style="margin-top:var(--wp--preset--spacing--20)" class="wp-block-wporg-code-table" id="uses"><figure class="wp-block-table "><table><thead><tr><th scope="col">Uses</th><th scope="col">Description</th></tr></thead><tbody><tr class=""><td><a href="https://developer.wordpress.org/reference/classes/wp_widget/">WP_Widget</a><code>wp-includes/class-wp-widget.php


Core base class extended to register widgets.

Changelog

Version Description
2.8.0 Introduced.