mont58-coffee-label/mont58-coffee-label.php

<?php
/**
 * Plugin Name: Mont58 Coffee Label
 * Plugin URI: https://example.com/
 * Description: A plugin for displaying coffee labels.
 * Version: 1.0.0
 * Author: Autonomic Co-op
 * Author URI: https://autonomic.zone/
 * License: GPL2
*/


// Add a sidepanel on WooCommerce order pages
add_action('add_meta_boxes', 'mont58_coffee_label_add_sidepanel');

function mont58_coffee_label_add_sidepanel() {
  add_meta_box(
    'mont58_coffee_label_sidepanel',
    'Coffee Label',
    'mont58_coffee_label_render_sidepanel',
    'shop_order',
    'side',
    'high'
  );
}

function mont58_coffee_label_render_sidepanel($post) {
  // Render the content of the sidepanel here
  $order_id = $post->ID;
  echo '<a href="/coffee-label?order_id=' . $order_id . '" class="button button-primary">View Label</a>';
}

// Load custom template
function load_custom_template($template) {
  if (is_page('coffee-label')) {
    return plugin_dir_path(__FILE__) . 'template-order-label.php';
  }

  return $template;
}

add_filter('template_include', 'load_custom_template');