post-to-liascript-shortcode-button/post-to-liascript-shortcode-button.php

<?php
/*
Plugin Name: Post to LiaScript Shortcode Button
Description: Ermittelt den Content und Titel eines Beitrags, konvertiert den Inhalt in gut strukturiertes Markdown, fügt eine TULLU-Lizenz hinzu, komprimiert und kodiert den Inhalt und gibt einen LiaScript-Link über einen Shortcode aus.
Version: 1.0
Author: Joachim Happel
*/

if (!defined('ABSPATH')) {
    exit; // Exit if accessed directly.
}

// Include Composer autoload
require_once __DIR__ . '/vendor/autoload.php';

#use Parsedown;
use League\HTMLToMarkdown\HtmlConverter;

class PostToLiaScriptShortcodeButton {

    public function __construct() {
        add_shortcode('shareliascriptbtn', array($this, 'generate_lia_script_link'));
    }

    public function generate_lia_script_link($atts) {
        $atts = shortcode_atts(array(
            'class' => 'button',
            'label' => 'Teilen'
        ), $atts, 'shareliascriptbtn');

        if (is_singular()) {
            global $post;

            $title = get_the_title($post->ID);
            $content = apply_filters('the_content', $post->post_content);
            
            // Get the license terms
            $terms = wp_get_post_terms($post->ID, 'license');
            if (!empty($terms) && !is_wp_error($terms)) {
                $term = $terms[0];
                $license = $term->name;
                $license_url = term_description($term->term_id);
                $license_icon_url = "https://mirrors.creativecommons.org/presskit/buttons/88x31/png/" . str_replace("cc-", "", $term->slug) . ".png";
            } else {
                // Default values if no license term is found
                $license = "No License";
                $license_url = "#";
                $license_icon_url = "#";
            }

            // Get author and site information
            $post_author_id = $post->post_author;
            $post_author_name = get_the_author_meta('display_name', $post_author_id);
            $post_author_url = get_author_posts_url($post_author_id);
            $home_url = home_url();
            $blogname = get_bloginfo('name');
            $post_url = get_permalink($post->ID);

            // License HTML snippet
            $license_html = "
            <div class='oer-cc-licensebox'>
                <a href='{$license_url}'>
                    <img decoding='async' src='{$license_icon_url}' alt='{$license}'>
                </a>
                <br>
                Weiternutzung als OER ausdrücklich erlaubt: Dieses OER ist - sofern dies bei Teilinhalten nicht anders angegeben - lizenziert unter
                <a href='{$license_url}' rel='license' target='_blank'>{$license}</a>. 
                Nennung gemäß <a href='https://open-educational-resources.de/oer-tullu-regel/'>TULLU-Regel</a> bitte wie folgt:<br>
                <i>
                    <span xmlns:dct='http://purl.org/dc/terms/' property='dct:title'><a href='{$post_url}' xmlns:cc='http://creativecommons.org/ns#' rel='cc:attributionURL dct:creator'>{$title}</a> (<a href='{$home_url}' xmlns:cc='http://creativecommons.org/ns#' rel='cc:attributionURL dct:publisher'><em>{$blogname}</em></a>)</span>
                    von <span xmlns:cc='http://creativecommons.org/ns#' property='cc:attributionName dct:author'><a href='{$post_author_url}' rel='tag'>{$post_author_name}</a></span>, 
                    Lizenz: <a href='{$license_url}' target='_blank'>{$license}</a>
                </i>.
            </div>";

            $license_markdown = "\n\n---\n\n### OER-Lizenz\n\n".
            "Dieses Werk ist - sofern Inhalte nicht anders gekennzeichnet - lizenziert unter".
                "\n[$title]($post_url)\n[$license]($license_url) [$post_author_name]($post_author_url)/[$blogname]($home_url)";
            
            // Convert content to Markdown
            $markdownContent = $this->convert_to_markdown($content).$license_markdown;


            // Convert Markdown content to gzip Base64
            $contentHash = $this->create_gzip_base64_data($markdownContent);

            // Generate the link
            $link = sprintf(
                '<a href="https://liascript.github.io/LiveEditor/?/show/code/%s" class="%s" target="_blank">%s</a>',
                $contentHash,
                esc_attr($atts['class']),
                esc_html($atts['label'])
            );

            return $license_html.$link;
        }

        return '';
    }

    private function convert_to_markdown($content) {
        #$parsedown = new Parsedown();
        #$contenthtml = $parsedown->text($content);
        $converter = new HtmlConverter(array('strip_tags' => true));
        $markdown = $converter->convert($content);
       # $markdown = strip_tags($markdown);
        return $markdown;
    }

    private function create_gzip_base64_data($data) {
        $gzData = gzencode($data, 9);
        return base64_encode($gzData);
    }
}

// Initialize the plugin
new PostToLiaScriptShortcodeButton();