重新阅读您的问题并修改解决方案。它现在是一个页面模板，应该设置为需要保护其内容的页面。它依赖于包含来自的html的“登录”帖子。

<?php
/*
Template Name: Protected Page
*/


// Standard HTML of Theme

    global $post;

    // check if authentication has been made
    if( verifyAuthentication($_POST[\'authCode\']) ) {

        // display protected content
        the_content();
    }       
    else {

        // fetch the login form html from "login" post. Or you can read from a file or some admin settings of your plugin.
        $login_post = get_post( url_to_postid("login") );

        // display the html form
        echo apply_filters(\'the_content\',$login_post->post_content );
    }


// Standard HTML of Theme