使用 WP User Frontend 用户心插件实现文章订阅功能

$current_user      = wpuf_get_user();
$user_subscription = new WPUF_User_Subscription($current_user);
$user_sub          = $user_subscription->current_pack();
$sub_id            = $current_user->subscription()->current_pack_id();

add_filter('the_content', function ($content)
{
    $current_user      = wpuf_get_user();
    $user_subscription = new WPUF_User_Subscription($current_user);
    $user_sub          = $user_subscription->current_pack();
    $sub_id            = $current_user->subscription()->current_pack_id();
 
    $is_paid_post      = get_post_meta(get_the_ID(), '_wpuf_is_paid_user', true) === 'on';
 
    // 非付费文章不做处理，直接返回
    if ( ! $is_paid_post) {
        return $content;
    }
 
    if ($sub_id) {
        // 有订阅包，并且已过期时，$subs_expired 为 true
        $subs_expired = $user_subscription->expired();
    } else {
        $subs_expired = false;
    }
 
    if ( ! is_user_logged_in()) {
        $filtered_content = '此文章需要登录后才能查看，请登录。';
    } else {
 
        if ($subs_expired) {
            $filtered_content = '此文章需要订阅才能查看，请订阅。';
        } else {
            $filtered_content = $content;
        }
 
    }
 
    return $filtered_content;
 
});