I have been using custom post types in WordPress for a long time now…. In fact each new theme or plugin I write I tend to integrate a custom post type and some supplementary meta boxes here and there. If you have no idea what i’m talking about then this article probably isn’t for you… however read on and I shall explain briefly.

Custom post types are wonderful for parts of sites that don’t generally fit into the standard Post or Page model. For instance WP Ecommerce (the most popular WP shopping cart) has just started using custom post types for storing their products… you will get the idea, products being a custom post type. If I say that they are a way of storing things in WordPress that can, if needed, provide a way of administering these objects as if they were a page like any other.

Adding them yourself requires some code and adding the fields that will appear on the page will require some more. This isn’t what I want to go over right now as there is an easier way. To get an idea of what I mean, see the following screenshots…

Note the bottom three, they are custom post types

This admin interface is generated for you with 0 effort.

“Products” is generated by WP Ecommerce and my theme added “FAQs” and “Photography”. The second screenshot shows the admin interface, similar to the post/page editor, which is generated and the meta boxes which can be added very easily indeed to make it appear that way. The way that these can be added without writing any code would be to use one of the ‘More’ plugins…. These are More Fields, More Types and More Taxonomies… all freely available WordPress plugins although I tend not to use them these days (I write them into my themes instead). Take a look though.

This article was really to outline what you do with the data within these types in the real world. Of course storing the data is easy, using it requires some imagination really. The post type items are stored in the wp_posts table and the fields you add as meta data are stored in wp_usermeta. You can easily retrieve the information using standard WordPress functions.

The following function can be used to get all of the photography items and store them in an Array of Objects for looping and output any way you see fit…

function get_custom_post_type_items($custom_post_type) {
	$args = array(
	'post_type' => $custom_post_type,
	'post_status' => 'publish',
	'posts_per_page' =>-1,
	'orderby' => 'post_date',
	'order' => 'DESC'
	);

	$posts = new WP_Query($args);
	$return = array();

	if ($posts->have_posts()) {
		while ($posts->have_posts()) {
			$posts->the_post();

			$post_id = get_the_ID();

			$sub_post = new stdClass();
			$sub_post->post_id = $post_id;
			$sub_post->title = get_the_title();
			$sub_post->permalink = get_permalink($post_id);
			$sub_post->content = wpautop(get_the_content());
			$sub_post->meta_data = get_post_meta($post_id, 'meta_data_name, true);

			$return[] = $sub_post;
		}
	}

	wp_reset_query();

	return $return;
}

You can use this function in your functions.php file in your theme to be called by a page template or a shortcode if you add one to return the items you have added as custom post types. I have added a single meta data item called meta_data in each row which gets a custom field from the custom post type item called meta_data_name. In my Photography example I would just have more lines like this to get the various items from my custom meta box

$sub_post->png_image = get_post_meta($post_id, 'png_image_url, true);

Another good example use of this function would be for a featured items slider that you often see at the top of websites. One or more pages might have a portfolio item slider or a rotating banner or something. In that case you would call my function from your header.php file then loop through it outputting the appropriate HTML per line before using something like a jQuery call to construct the slider.

When you understand the applications for custom post types you might be finding yourself using them in more and more creative ways. I wrote a custom meta box a while back to link custom post type items to each other across different types. This was to allow staff member types to be linked to team and office types and so on. Then using this association you can output something like a dynamic organisational chart using a shortcode or a custom page template without having to hard code a thing.

This is a thinker, I imagine, for some people. Get in touch with me if you want any help putting these custom post types in place and utilising them on your site.