add_shortcode('testimonials', 'testimonial_query');
function testimonial_query($atts, $content){
extract(shortcode_atts(array( // a few default values

'id' => null,
'posts_per_page' => '1',
'caller_get_posts' => 1)
, $atts));
$args = array(
'post_type' => 'testimonial',
'numberposts' => -1
);
global $post;
$posts = new WP_Query($args);
$output = '';
if ($posts->have_posts( $attributes['id']))
while ($posts->have_posts( $attributes['id'])):
$posts->the_post();
$url = wp_get_attachment_url( get_post_thumbnail_id($post->ID), 'thumbnail' );
$out = '<div class="testimonial-img">
<img src="'.$url.'" />
</div>
<div class="testimonial_content">
<img src="'.get_field('logo').'" alt="icon">
<p class="testimonial_desc">'.get_the_content().'</p>
<div class="author-details">
<img src="'.get_field('author_image').'" alt="image">
<p>'.get_field('author_name').' <span>'.get_field('author_designation').'</span></p>
</div>';
// add here more...
$out .='</div>';
endwhile;
else
return; // no posts found

wp_reset_query();
return html_entity_decode($out);
}