So far in this series, you’ve created your own theme and plugin and now you’ll move on to adding custom post types and taxonomies to your site. In this tutorial you’re going to learn:<\/p>\n
- \n
- What custom post types and taxonomies are, how they differ from the ones you get with vanilla WordPress, and how they can help you.<\/li>\n
- How to register\u00a0custom post types and taxonomies in a plugin.<\/li>\n
- How to add a taxonomy to (or remove one from)\u00a0a post type.<\/li>\n
- How to display custom post types and taxonomies, including via template files.<\/li>\n
- Which functions you can use to fetch posts using your custom post types and taxonomies.<\/li>\n<\/ul>\n
Let’s start with an overview.<\/p>\n
Missed a tutorial in our WordPress Development for Intermediate Users series? You can catch up on all seven posts here:<\/strong><\/p>\n
- \n
- WordPress Development for Intermediate Users: Theme Development in Detail<\/a><\/li>\n
- WordPress Development for Intermediate Users: Making Your Themes Customizer-Ready<\/a><\/li>\n
- WordPress Development for Intermediate Users: Building Plugins<\/a><\/li>\n
- WordPress Development for Intermediate Users: Custom Post Types and Taxonomies<\/a><\/li>\n
- WordPress Development for Intermediate Users: Queries and Loops<\/a><\/li>\n
- WordPress Development for Intermediate Users: Custom Fields and Metadata<\/a><\/li>\n
- WordPress Development for Intermediate Users: Internationalization<\/a><\/li>\n<\/ul>\nThat’s right, tons of WordPress knowledge, peer review, instructor feedback and certification, for free for WPMU DEV members<\/span>Start Learning<\/span><\/a>\n
Post Types and Taxonomies in WordPress<\/h3>\n
WordPress comes with a number of post types<\/a> and taxonomies<\/a> already included. The post types are:<\/p>\n
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- Post<\/strong> – the posts you use for your blog.<\/li>\n
- Page<\/strong> – static pages.<\/li>\n
- Attachment<\/strong> – media files.<\/li>\n
- Revision<\/strong> – each revision for each post is stored as a post of the ‘revision’ post type.<\/li>\n
- Navigation menu item<\/strong> – every item in your navigation menus is stored against this post type.<\/li>\n<\/ul>\n
The word “post” can be a bit confusing when it comes to WordPress. Let’s take a look at some of the terminology, and try to get it straight:<\/p>\n
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- post<\/strong> (with a lower case “p”) – in the database, WordPress stores every item\u00a0of every post type as a post<\/em>. So if you create a post type called product<\/em> and then create products for your site, they go in the wp_posts<\/em> table of the database in the same way a standard post would. The difference is that the post type stored against that post as a value in the database would be product<\/em> instead of post<\/em>.<\/li>\n
- Post<\/strong> – this is a post type, in the same way that any custom post type you create is a post type. A Post<\/em> is the post type that comes with WordPress for blog posts, updates, news items etc.<\/li>\n
- post type<\/strong> – this refers to any post type (with a little “p”) including Pages, Posts etc. Don’t confuse it with post formats – post format is a taxonomy that’s used to classify Posts, as you’ll see shortly.<\/li>\n<\/ul>\n
In this part of the series, I’m going to use a capital P to refer to Posts<\/em> in the context of blog posts, and a lower case p to refer to posts<\/em> in the more general sense, including posts of any post type. I’m not doing that in the rest of the series though as it’s not the usual way to write, so please don’t get confused!<\/p>\n
Phew! So that’s post types. What about taxonomies? Well, WordPress also comes with some of these out of the box:<\/p>\n
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- Category<\/strong> – a hierarchical taxonomy (meaning you can nest categories inside each other) used for Posts.<\/li>\n
- Tag<\/strong> – a non-hierarchical taxonomy used for Posts.<\/li>\n
- Link Category<\/strong> – used to classify links, if you’re using the old “blogroll” function. This is disabled by default so I wouldn’t worry about it if I were you.<\/li>\n
- Post Format<\/strong> – another taxonomy for classifying Posts, which isn’t hierarchical. You can use this to display\u00a0different post formats differently, using the relevant template file.<\/li>\n<\/ul>\n
By default, three of these taxonomies apply to Posts and one to Links, but there’s no reason why you can’t make them also apply to another post type, or remove them from the default post type. Later on, I’ll show you how to make tags and categories apply to a new post type that you register, add them to Pages, or remove them from Posts if you don’t want to use them.<\/p>\n
Each taxonomy has terms, which are the values you use to classify your content. So each category you add to your Posts is a term in the category taxonomy. Once you’ve registered a taxonomy, you can add terms to it via the admin screens – either by a dedicated screen for adding terms or when editing your posts.<\/p>\n
Now you know what post types and taxonomies are, let’s see how you create a post type for your site.<\/p>\n
Registering a Post Type<\/h3>\n
The best way to register a post type is by writing a plugin to do so. This is because if you add the post type to your theme and then switch themes at a later date, you’ll lose your post types.<\/p>\n
Let’s create a plugin to register our post types and taxonomies for this part of the series. In your development site’s wp-content\/plugins folder<\/em>, create a file\u00a0for your plugin and add the opening text to it as you would for any other plugin. I’m not going to show you how to do this as it should be second nature by now, but if you need to check, take a look at the source files<\/a> for this series.<\/p>\n
Next, create a function to register your post type. This needs to do three things:<\/p>\n
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- Define the labels for the post type that your users will see when working with them in the admin screens.<\/li>\n
- Define the other arguments for the post type, such as whether it’s hierarchical (like a Page) or not (like a Post).<\/li>\n
- Register the post type using the
register_post_type()<\/code><\/a> function.<\/li>\n<\/ul>\nYour function containing all this is then hooked to the
init<\/code> action hook.<\/p>\nHere’s my function registering a project post type:<\/p>\n
- Tag<\/strong> – a non-hierarchical taxonomy used for Posts.<\/li>\n
- Post<\/strong> – this is a post type, in the same way that any custom post type you create is a post type. A Post<\/em> is the post type that comes with WordPress for blog posts, updates, news items etc.<\/li>\n
- Page<\/strong> – static pages.<\/li>\n
- WordPress Development for Intermediate Users: Making Your Themes Customizer-Ready<\/a><\/li>\n
- WordPress Development for Intermediate Users: Theme Development in Detail<\/a><\/li>\n
![\"Project](\"https:\/\/wpmudev.com\/blog\/wp-content\/uploads\/2016\/05\/project-cpt-admin.png\")
<\/p>\n![\"The](\"https:\/\/wpmudev.com\/blog\/wp-content\/uploads\/2016\/05\/service-taxonomy-admin.png\")
<\/p>\n![\"Editing](\"https:\/\/wpmudev.com\/blog\/wp-content\/uploads\/2016\/06\/page-edit-categories.png\")
<\/p>\n![\"The](\"https:\/\/wpmudev.com\/blog\/wp-content\/uploads\/2016\/05\/project-archive.png\")
<\/p>\n![\"Service](\"https:\/\/wpmudev.com\/blog\/wp-content\/uploads\/2016\/05\/service-archive.png\")
<\/p>\n![\"Projects](\"https:\/\/wpmudev.com\/blog\/wp-content\/uploads\/2016\/05\/projects-archive-with-image.png\")
<\/p>\n![\"The](\"https:\/\/wpmudev.com\/blog\/wp-content\/uploads\/2016\/05\/tax-term-archive-before.png\")
<\/p>\n![\"The](\"https:\/\/wpmudev.com\/blog\/wp-content\/uploads\/2016\/05\/tax-term-archive-new.png\")
<\/p>\n![\"Descriptions](\"https:\/\/wpmudev.com\/blog\/wp-content\/uploads\/2016\/05\/services-descriptions-admin.png\")
<\/p>\n![\"Taxonomy](\"https:\/\/wpmudev.com\/blog\/wp-content\/uploads\/2016\/05\/tax-term-description-frontend.png\")
<\/p>\n