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

<?php

$specificData = [
  'backgroundImage' => $page->backgroundImage()->toFile()?->url(),
  'projects' => $page->children()->listed()->map(function($project) {
    return [
      'title'          => $project->title()->value(),
      'slug'           => $project->slug(),
      'catchPhrase'    => $project->catchPhrase()->value(),
      'description'    => $project->description()->value(),
      'thumbnail'      => $project->thumbnail()->toFile()?->url(),
      'imagesGallery'  => $project->imagesGallery()->toFiles()->map(fn($f) => [
                            'src'     => $f->url(),
                            'srcset'  => $f->srcset('gallery'),
                            'webp'    => $f->srcset('gallery-webp'),
                          ])->values(),
      'mockup'                => $project->mockup()->toFile()?->url(),
      'galleryBackgroundColor' => $project->galleryBackgroundColor()->value(),
      'keywords'       => $project->keywords()->toStructure()->map(fn($i) => [
                            'label' => $i->label()->value(),
                            'text'  => $i->text()->value(),
                          ])->values(),
      'externalLinks'  => $project->externalLinks()->toStructure()->map(fn($i) => [
                            'label' => $i->label()->value(),
                            'url'   => $i->url()->value(),
                          ])->values(),
    ];
  })->values()
];

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

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