WordPress 头像挂件插件代码：用户自定义头像

以下是一个简单的 WordPress 头像挂件的功能代码，允许用户自行选择：

/*
Plugin Name: Avatar Widget
Plugin URI: http://example.com
Description: A simple avatar widget that allows users to choose their own avatar.
Version: 1.0
Author: Your Name
Author URI: http://example.com
*/

class Avatar_Widget extends WP_Widget {

    /**
     * Register widget with WordPress.
     */
    public function __construct() {
        parent::__construct(
            'avatar_widget', // Base ID
            'Avatar Widget', // Name
            array( 'description' => __( 'A simple avatar widget that allows users to choose their own avatar.', 'text_domain' ), ) // Args
        );
    }

    /**
     * Front-end display of widget.
     */
    public function widget( $args, $instance ) {
        echo $args['before_widget'];
        if ( ! empty( $instance['title'] ) ) {
            echo $args['before_title'] . apply_filters( 'widget_title', $instance['title'] ) . $args['after_title'];
        }
        // Output avatar selection form here
        $user_id = get_current_user_id();
        $avatar = get_avatar_url( $user_id, array( 'size' => 96 ) );
        ?>
        <form method='post' action='<?php echo esc_url( admin_url('admin-post.php') ); ?>'>
            <input type='hidden' name='action' value='avatar_widget_update'>
            <input type='hidden' name='user_id' value='<?php echo esc_attr( $user_id ); ?>'>
            <label for='avatar_url'><?php _e( 'Avatar URL:', 'text_domain' ); ?></label>
            <input type='text' name='avatar_url' id='avatar_url' value='<?php echo esc_attr( $avatar ); ?>'>
            <br>
            <input type='submit' value='<?php _e( 'Save Avatar', 'text_domain' ); ?>'>
        </form>
        <?php
        echo $args['after_widget'];
    }

    /**
     * Sanitize widget form values as they are saved.
     */
    public function update( $new_instance, $old_instance ) {
        $instance = array();
        $instance['title'] = strip_tags( $new_instance['title'] );

        return $instance;
    }

    /**
     * Back-end widget form.
     */
    public function form( $instance ) {
        $title = ! empty( $instance['title'] ) ? $instance['title'] : __( 'New title', 'text_domain' );
        ?>
        <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( $title ); ?>'>
        </p>
        <?php
    }

}

// Register the widget
function register_avatar_widget() {
    register_widget( 'Avatar_Widget' );
}
add_action( 'widgets_init', 'register_avatar_widget' );

// Handle form submission
function avatar_widget_update() {
    $user_id = $_POST['user_id'];
    $avatar_url = $_POST['avatar_url'];

    // Save the user's selected avatar URL
    update_user_meta( $user_id, 'avatar_url', $avatar_url );

    // Redirect to the widget's page
    wp_redirect( $_SERVER['HTTP_REFERER'] );
}
add_action( 'admin_post_avatar_widget_update', 'avatar_widget_update' );

这个代码创建一个 WordPress 挂件，允许用户选择和保存他们自己的头像。挂件包括一个表单，用户可以输入他们选择的头像 URL，然后保存到他们的用户资料中。