world-game/site/templates/article.json.php

<?php

$related = $page->relatedArticles()->toPages();
if ($related->isEmpty()) {
  $related = $page->siblings()->listed()->not($page)->shuffle()->limit(3);
}

$specificData = [
  'published'      => $page->published()->toDate('d/m/Y'),
  'intro'     => $page->intro()->value(),
  'cover'     => $page->cover()->toFile()?->url(),
  'body'      => (string) $page->body()->toBlocks(),
  'related'   => $related->map(function($rec) {
    return [
      'title' => $rec->title()->value(),
      'slug'  => $rec->slug(),
      'date'  => $rec->date()->toDate('d/m/Y'),
      'cover' => $rec->cover()->toFile()?->url(),
    ];
  })->values(),
  'parentUrl' => $page->parent()->url(),
];

$pageData = array_merge($genericData, $specificData);

header('Content-Type: application/json');
echo json_encode($pageData);