Example of apprch-wp-srcset

example_apprch-wp-srcset.php

<?php

    /**
    * Example of using apprch_wp_srcset() within WordPress loop. For function code to paste in to functions.php file, see URL below.
    * @link https://gist.github.com/piperhaywood/96ac07ea5f4999512275
    * 
    * In example, browsers without 
    * 'srcset' image attribute support are served 'large' image in 'src'.WordPress function to 
    * create HTML5 image element with 'srcset' and 'sizes' attributes for JPEGs and PNGs. 
    * 
    * Image element returned by example:
    * <img class="featured-image" alt="The image alt" srcset="http://your-site.com/wp-content/uploads/2014/12/your-image-150x150.jpg 150px, http://your-site.com/wp-content/uploads/2014/12/your-image-300x300.jpg 300px, http://your-site.com/wp-content/uploads/2014/12/your-image-640x640.jpg 640px, http://your-site.com/wp-content/uploads/2014/12/your-image-640x640.jpg 1000px" sizes="100vw" src="http://your-site.com/wp-content/uploads/2014/12/your-image-640x640.jpg >
    */
   
    if (has_post_thumbnail()) : 
    
        $image_id = get_post_thumbnail_id();
        $src_size = 'large';
        $img_sizes = '100vw';
        $class = 'featured-image';
        
        echo apprch_wp_srcset( $image_id, $src_size, $sizes, $class );
        
    endif;
    
?>