Smallest HATEOAS sample in the world [citation needed]. Work in Progress!

index.php

<?php

use Respect\Rest\Router;

$r3 = new Router();
$routes = [];

$routes['singleAuthor'] = $r3->any('/authors/*',       'MySingleAuthorClass');
$routes['singlePost']   = $r3->any('/posts/*',         'MySinglePostClass');
$routes['postsList']    = $r3->any('/posts',           'MyPostsListClass');
$routes['archives']     = $r3->any('/authors/*/posts', 'MyArchivesClass');

$routes['singleAuthor']->trough(
    function ($author) use ($routes) {
        $author['_links'] = [
            'archives' => [
                'href' => $routes['archives']->createUri($author['id']),
                'title' => "Archives for $author['name']"
            ],
            'dc:image' => [
                'href' => $author['profile_image_url']
            ]
        ];
        return $author;
    }
);

$routes['singlePost']->trough(
    function ($post) use ($routes) {
        $post['_links'] = [
            'collection' => [
                'href' => $routes['postsList']->createUri(),
                'title' => "All Posts"
            ],
            'author' => [
                'href' => $routes['singleAuthor']->createUri($post['author']['id']),
                'title' => "Archives for $post['author']['name']"
            ]
        ];
        return $post;
    }
);

$routes['allPosts']->trough(
    function ($posts) use ($routes) {
        $itemLinks = [];
        foreach ($posts as $post) {
            $links[] = [
                'href' => $routes['singlePost']->createUri($post['id']),
                'title' => "$post['title']"
            ];
        }
        $posts['_links']['item'] = $itemLinks;
        return $posts;
    }
);

$r3->always(
    'Accept', 
    array(
        'application/json' => $jsonEncoder = function ($data) {
            header('Content-Type: application/json');
            return json_encode($data);
        },
        '.json' => $jsonEncoder
    )
);