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WordPress跨站点数据共享全面指南

WordPress多站点网络功能允许在同一个WordPress主题中安装中运行多个网站。本文将深入探讨如何在WordPress多站点环境中实现高效、安全的数据共享。

一、基础数据共享方法

1. 使用switch_to_blog函数

// 获取主站点文章并在子站点显示
function display_main_site_posts() {
    $main_site_id = 1; // 主站点ID
    $posts = [];
    
    switch_to_blog($main_site_id);
    $posts = get_posts([
        'posts_per_page' => 5,
        'orderby' => 'date',
        'order' => 'DESC'
    ]);
    restore_current_blog();
    
    return $posts;
}

// 使用示例
add_shortcode('main_site_posts', function() {
    $posts = display_main_site_posts();
    $output = '<ul class="main-site-posts">';
    
    foreach ($posts as $post) {
        $output .= sprintf(
            '<li><a href="%s">%s</a></li>',
            get_permalink($post->ID),
            $post->post_title
        );
    }
    
    $output .= '</ul>';
    return $output;
});

2. 全局表格访问

// 直接查询wp_posts表获取所有站点文章
function get_all_sites_posts($limit = 10) {
    global $wpdb;
    
    return $wpdb->get_results(
        "SELECT * FROM {$wpdb->base_prefix}posts 
         WHERE post_type = 'post' AND post_status = 'publish'
         ORDER BY post_date DESC LIMIT %d",
        $limit
    );
}

二、高级共享技术

1. 共享用户数据

// 获取网络所有用户
function get_network_users($args = []) {
    global $wpdb;
    
    $defaults = [
        'number' => 20,
        'offset' => 0,
        'orderby' => 'user_registered',
        'order' => 'DESC'
    ];
    $args = wp_parse_args($args, $defaults);
    
    return $wpdb->get_results(
        $wpdb->prepare(
            "SELECT * FROM {$wpdb->base_prefix}users 
             ORDER BY {$args['orderby']} {$args['order']}
             LIMIT %d, %d",
            $args['offset'],
            $args['number']
        )
    );
}

// 获取用户在所有站点的角色
function get_user_network_roles($user_id) {
    global $wpdb;
    
    $roles = [];
    $blogs = get_blogs_of_user($user_id);
    
    foreach ($blogs as $blog_id) {
        switch_to_blog($blog_id);
        $user = new WP_User($user_id);
        $roles[$blog_id] = $user->roles;
        restore_current_blog();
    }
    
    return $roles;
}

2. 共享媒体库

// 跨站点共享媒体库
function share_media_across_sites($source_site_id, $attachment_id, $target_site_id) {
    switch_to_blog($source_site_id);
    $file = get_attached_file($attachment_id);
    $metadata = wp_get_attachment_metadata($attachment_id);
    $mime_type = get_post_mime_type($attachment_id);
    restore_current_blog();
    
    switch_to_blog($target_site_id);
    $upload_dir = wp_upload_dir();
    $new_file = $upload_dir['path'] . '/' . basename($file);
    
    if (!copy($file, $new_file)) {
        restore_current_blog();
        return false;
    }
    
    $attachment = [
        'post_mime_type' => $mime_type,
        'post_title' => preg_replace('/\.[^.]+$/', '', basename($file)),
        'post_content' => '',
        'post_status' => 'inherit'
    ];
    
    $new_attachment_id = wp_insert_attachment($attachment, $new_file);
    wp_update_attachment_metadata($new_attachment_id, $metadata);
    restore_current_blog();
    
    return $new_attachment_id;
}

三、性能优化方案

1. 共享数据缓存

// 带缓存的跨站点数据获取
function get_cross_site_data($site_id, $callback, $cache_key, $expire = 3600) {
    $cache = get_site_transient($cache_key);
    
    if ($cache !== false) {
        return $cache;
    }
    
    switch_to_blog($site_id);
    $data = call_user_func($callback);
    restore_current_blog();
    
    set_site_transient($cache_key, $data, $expire);
    return $data;
}

// 使用示例
$latest_posts = get_cross_site_data(
    1, // 主站点ID
    function() {
        return get_posts(['posts_per_page' => 5]);
    },
    'main_site_latest_posts',
    HOUR_IN_SECONDS
);

2. 批量数据获取

// 批量获取多个站点数据
function batch_get_sites_data($sites, $callback) {
    $results = [];
    
    foreach ($sites as $site_id) {
        switch_to_blog($site_id);
        $results[$site_id] = call_user_func($callback, $site_id);
        restore_current_blog();
    }
    
    return $results;
}

// 使用示例
$sites = [1, 2, 3]; // 站点ID数组
$all_posts = batch_get_sites_data($sites, function($site_id) {
    return get_posts([
        'posts_per_page' => 3,
        'fields' => 'ids'
    ]);
});

四、安全与权限控制

1. 跨站点权限验证

// 验证用户是否有权限访问跨站点数据
function can_access_cross_site_data($user_id, $site_id) {
    $user_blogs = get_blogs_of_user($user_id);
    
    if (!isset($user_blogs[$site_id])) {
        return false;
    }
    
    switch_to_blog($site_id);
    $user = new WP_User($user_id);
    $has_access = $user->has_cap('read');
    restore_current_blog();
    
    return $has_access;
}

2. 数据共享白名单

// 设置可共享的数据类型
function get_shareable_post_types() {
    return apply_filters('shareable_post_types', [
        'post' => '文章',
        'product' => '产品'
    ]);
}

// 验证是否可共享
function is_post_type_shareable($post_type) {
    $shareable_types = get_shareable_post_types();
    return isset($shareable_types[$post_type]);
}

五、实战应用案例

1. 创建全局内容聚合页面

// 聚合所有站点最新内容
function aggregate_network_content($limit = 10) {
    $sites = get_sites(['number' => 50]); // 获取前50个站点
    $all_posts = [];
    
    foreach ($sites as $site) {
        switch_to_blog($site->blog_id);
        $posts = get_posts([
            'posts_per_page' => $limit,
            'post_status' => 'publish'
        ]);
        
        foreach ($posts as $post) {
            $post->blog_id = $site->blog_id;
            $post->blog_name = get_bloginfo('name');
            $all_posts[] = $post;
        }
        
        restore_current_blog();
    }
    
    // 按日期排序
    usort($all_posts, function($a, $b) {
        return strtotime($b->post_date) - strtotime($a->post_date);
    });
    
    return array_slice($all_posts, 0, $limit);
}

2. 多站点搜索功能

// 跨站点搜索实现
function network_wide_search($query, $limit = 10) {
    $sites = get_sites(['number' => 20]); // 限制搜索前20个站点
    $results = [];
    
    foreach ($sites as $site) {
        switch_to_blog($site->blog_id);
        
        $site_results = new WP_Query([
            's' => $query,
            'posts_per_page' => $limit,
            'post_status' => 'publish'
        ]);
        
        if ($site_results->have_posts()) {
            while ($site_results->have_posts()) {
                $site_results->the_post();
                $results[] = [
                    'blog_id' => $site->blog_id,
                    'blog_name' => get_bloginfo('name'),
                    'post' => get_post()
                ];
            }
        }
        
        restore_current_blog();
    }
    
    return $results;
}