PHP: WP AJAX

gistfile1

function get_more_posts(){

	$main_args = array(
		'post_type' =>'post',
		'post_status' => 'publish',
		'posts_per_page' => $_POST['post_number'],
		'paged' => $_POST['pag']
	);

	$main_posts = new WP_Query($main_args);

	$html = '';

	// the query is complete, but we didn't find anything
	if( $main_posts->found_posts == 0 ){ 
		$html .= '<div class="alert">';
		$html .= 'Sorry, no more posts found.';
		$html .= '</div>';

		// return json
		echo json_encode(array(
			'html'      => $html,
			'have_more' => false,
			'none_found' => true,
			'dump' => false, 
			'status'    => 'success',
			'args' => $main_args,
		));
		exit;

	} else {

		//we found posts, now output the correct html depending on arguments

		$html = '';
		$post_count = 0;
		while ( $main_posts->have_posts() ) { 

			$main_posts->the_post();

				html .= '';
		}

	}

	$have_more = true;
	if( $main_posts->max_num_pages == $_POST['pag'] || $_POST['post_number'] == '-1' ){
		$have_more = false;
	}

	$found = $main_posts->found_posts;

	// return json
	echo json_encode(array(
		'html' => $html,
		'have_more' => $have_more,
		'found' => $found,
		'none_found' => false,
		'dump' => $main_posts->request,   
		'status'    => 'success'
	));

	exit;
}

add_action('wp_ajax_get_more_posts', 'get_more_posts');
add_action('wp_ajax_nopriv_get_more_posts', 'get_more_posts');