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);

            
            // Convert content to Markdown
            $markdownContent = $this->convert_to_markdown($content);

            // Append TULLU license
            $license = "\n\n---\n\n" . "This work is licensed under the TULLU rule. For more information, visit https://open-educational-resources.de/oer-tullu-regel/";

            $markdownContent .= $license;

            // 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 $link;
        }

        return '';
    }

    private function convert_to_markdown($content) {
        $parsedown = new Parsedown();
        $html = $parsedown->text($content);
        $converter = new HtmlConverter();
        $markdown = $converter->convert($html);
        $markdown = strip_tags($markdown);
        return $markdown;
    }

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

// Initialize the plugin
new PostToLiaScriptShortcodeButton();