Kirby CMS Tag for srcset images. Supports the attributes "retina" (file name of the @2x resource), "alt" (alt text on img), "class" (additional class on the img element). Place under /site/tags/

srcset.php

<?php

kirbytext::$tags['srcset'] = array(
  'attr' => array(
    'retina',
    'alt',
    'class'
  ),
  'html' => function($tag) {

    $normal    = $tag->attr('srcset');
    $retina    = $tag->attr('retina');
    $alt       = $tag->attr('alt');
    $class     = $tag->attr('class');

    $html  = '<figure><img src="';
    $html .= $tag->page()->contentURL().'/'.$normal;
    $html .= '"';

    if($retina!=''){
      $html .= ' srcset="';
      $html .= $tag->page()->contentURL().'/'.$normal.' 1x, ';
      $html .= $tag->page()->contentURL().'/'.$retina.' 2x"';
    }

    if ($alt!=''){ $html .= ' alt="'.$alt.'"'; };
    if ($class!=''){ $html .= ' class="'.$class.'"'; };

    $html .= '></figure>';


    return $html;

  }
);