gistfile1.txt

<?php 
    snippet('header');
        $tag = urldecode(param('tag'));
            if(param('tag'))
                $articles=$pages->visible()->filterBy('tags',$tag,',')->sortBy('date')->flip();
?>

<main class="main">
    <section>
        <h1><?php echo $page->title() . ' ' . $tag ?></h1>
            <?php foreach($articles as $p): ?>
                <article>
                    <h1><a href="<?php echo $p->url()?>"><?php echo $p->title() ?></a></h1> 
                </article> 
           <?php endforeach?> 
    </section>
</main> 
<?php snippet('footer')?>