Full RESTful/Relational Blog in less than 100 lines [Work In Progress]

href.php

<?php

use Respect\Rest\Router;
use Respect\Relational\Mapper;
use Respect\Template\Xml;
use Respect\Template\Html;

$db = new Mapper(new PDO));
$db->postsBase = $db->select('id', 'title', 'text')->posts(
    $db->select('name', 'bio')->author)
);
$db->publicPosts = $db->postsBase->pendingAll();
$db->singlePost = $db->publicPosts->pending('id');
$db->archiveItem = $db->publicPosts->pendingAll(
    'YEAR(created_at)',
    'MONTH(created_at)',
    'DAY(created_at)'
);
$db->nextPost     = $db->post->limit(1)->pending('id>');
$db->prevPost     = $db->post->limit(1)->pending('id<');
$db->topPost      = $db->post->limit(1)->pending('MAX(id)');
$db->postComments = $db->comment->pending('post_id');
$db->userAuth     = $db->users->pending('username', 'MD5(password)');

$app = new Router;
$app->always('Accept', array(
    'application/json' => 'json_encode'
));
$htmlPostCollection = Html::schemaOrg('Blog');
$htmlPostItem       = Html::schemaOrg('BlogPosting');
$xmlPostCollection  = Xml::schemaOrg('Blog');
$xmlPostItem        = Xml::schemaOrg('BlogPosting');

$app->post('/posts',   $db->publicPosts->waiting('id', 'title', 'text', 'author_id')->authDigest('Sample Blog', $db->userAuth);
$app->post('/posts/*', $db->postComments->waiting('id', 'email', 'text');
$app->get('/posts', $db->publicPosts)
    ->rel(array(
        'item'    => $app->get('/posts/*', $db->singlePost)
                         ->rev('id') //id from parent data
                         ->rel(array(
                             'comment' => $app->get('/posts/*/comments' $db->postComments)
                                              ->rev('id')
                                              ->accept($postItemView = array(
                                                  'text/html' => $htmlPostItem,
                                                  'text/xml'  => $xmlPostItem))
                             'top'     => $app->get('/posts/top', $db->topPost )->accept($postItemView),
                             'next'    => $app->get(null,         $db->nextPost)->accept($postItemView),
                             'prev'    => $app->get(null,         $db->prevPost)->accept($postItemView)))
                         ->accept(array(
                             'text/html' => $htmlPostItem,
                             'text/xml'  => $xmlPostItem))
        'archive' => array(
            'year'  => $archiveItem = $app->get('/posts/archive/*/*/*', $db->archiveItem)
                                          ->accept(array(
                                              'text/html' => $htmlPostArchive,
                                              'text/xml'  => $xmlPostArchive))
            'month' => $archiveItem,
            'day'   => $archiveItem
  ))->accept(array(
        'text/html' => $htmlPostCollection
        'text/xml'  => $xmlPostCollection
  ));

@hussani not yet. ->pending, waiting(), ->rel, ->rev and ->schemaOrg are missing.

How would function the schemaOrg function?