[Wordpress] Load content via Ajax

load-ajax-content.php

// *** Load gallery on division template via Ajax ***
function load_ajax_content () {

    $pid = array( 'p' => $_POST['post_id'], 'post_type' => 'gallery' );
	$the_query = new WP_Query( $pid );

    if ($the_query->have_posts()) {
        while ( $the_query->have_posts() ) {
            $the_query->the_post();
			$images = get_field('photos');
			if( $images ):
				$data .= '<div class="gallery-slider">';
				foreach( $images as $image ):
					$data .= '
						<div style="background-image: url('.$image["sizes"]["fp-medium"].');">
							<a target="_blank" class="button-pin" href="https://pinterest.com/pin/create/button/?url=&media='.$image["sizes"]["fp-medium"].'&description="><i class="fa fa-pinterest-p"></i>in</a>
						</div>
						';
				endforeach;
				$data .= '</div>';
			endif;
            $data .= '
            <div class="row gallery-caption">
                <div class="columns large-5">
                    <h3 class="entry-title">'.get_the_title().'</h3>
                </div>
                <div class="columns large-7">'.get_the_content().'</div>
            </div>  
            ';
        }
    } 
    else {
        echo '<div id="postdata">'.__('Didnt find anything').'</div>';
    }
    wp_reset_postdata();

    echo '<div id="postdata">'.$data.'</div>';

}

add_action ( 'wp_ajax_nopriv_load-content', 'load_ajax_content' );
add_action ( 'wp_ajax_load-content', 'load_ajax_content' );