Registering custom post types in Wordpress - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a custom post type in WordPress?

A custom post type is a way to create content types other than the default posts and pages, like portfolios, testimonials, or products.

beginner

Which WordPress function is used to register a custom post type?

The function register_post_type() is used to create a new custom post type.

intermediate

What are the two main arguments passed to register_post_type()?

The first is the post type key (a string identifier), and the second is an array of options that define labels, visibility, and features.

intermediate

Why should you hook register_post_type() into the init action?

Because WordPress loads custom post types during initialization, hooking into init ensures your post type is registered early and available everywhere.

beginner

Name two common features you can enable for a custom post type.

You can enable features like title, editor, thumbnail, excerpt, and comments.

Which hook is best to use when registering a custom post type?

A wp_footer

B wp_head

C admin_menu

D init

The init hook runs early and is the recommended place to register custom post types.

What does the first argument of register_post_type() represent?

A The post content

B The post title

C The post type key (identifier)

D The post author

The first argument is a string that identifies the custom post type.

Which feature allows a custom post type to have a featured image?

A comments

B thumbnail

C excerpt

D author

The thumbnail feature enables featured images for the post type.

What is the purpose of the 'labels' array in register_post_type()?

A To define the text shown in the admin UI for the post type

B To set the post content

C To control the post's visibility on the site

D To assign categories

The 'labels' array customizes the names and messages shown in the WordPress admin for the post type.

If you want your custom post type to appear in the WordPress admin menu, which argument should you set?

A show_ui to true

B public to false

C has_archive to false

D exclude_from_search to true

Setting show_ui to true makes the post type visible in the admin menu.

Explain how to register a custom post type in WordPress and why it is useful.

Think about how WordPress organizes content beyond posts and pages.

Describe the role of the 'supports' argument when registering a custom post type.

It controls what editing tools the post type has.

Practice

1. What is the main purpose of registering a custom post type in WordPress?

easy

A. To create a new type of content different from posts and pages

B. To change the WordPress theme

C. To add a new user role

D. To install a plugin automatically

Solution

1. Step 1: Understand WordPress content types

   WordPress has default content types like posts and pages, but custom post types allow adding new content types.

2. Step 2: Purpose of custom post types

   Registering a custom post type lets you organize and display content that doesn't fit posts or pages.

3. Final Answer:

   To create a new type of content different from posts and pages -> Option A

4. Quick Check:

   Custom post types = new content types [OK]

Hint: Custom post types add new content types beyond posts/pages [OK]

Common Mistakes:

• Confusing custom post types with themes or plugins
• Thinking it changes user roles
• Assuming it installs plugins automatically

2. Which of the following is the correct way to hook the register_post_type function in WordPress?

easy

A. add_action('init', 'register_post_type')

B. add_action('wp_head', 'register_post_type')

C. add_filter('init', 'register_post_type')

D. add_action('admin_menu', 'register_post_type')

Solution

1. Step 1: Identify the correct hook for registering post types

   The init hook is the standard place to register custom post types in WordPress.

2. Step 2: Use add_action with 'init'

   Using add_action('init', 'register_post_type') correctly hooks the function to run at initialization.

3. Final Answer:

   add_action('init', 'register_post_type') -> Option A

4. Quick Check:

   Hook register_post_type on init [OK]

Hint: Use 'init' hook with add_action for registering post types [OK]

Common Mistakes:

• Using add_filter instead of add_action
• Hooking into 'wp_head' or 'admin_menu' incorrectly
• Calling register_post_type directly without a hook

3. What will be the effect of this code snippet?

add_action('init', function() {
  register_post_type('book', [
    'label' => 'Books',
    'public' => true,
    'supports' => ['title', 'editor']
  ]);
});

medium

A. Causes a syntax error due to missing semicolons

B. Creates a private post type called 'book' without editor support

C. Creates a new public post type called 'book' with title and editor support

D. Registers a taxonomy instead of a post type

Solution

1. Step 1: Analyze the register_post_type parameters

   The code registers a post type named 'book' with label 'Books', public visibility, and supports title and editor features.

2. Step 2: Understand the effect of 'public' and 'supports'

   Setting 'public' to true makes it visible on the site, and 'supports' enables editing title and content.

3. Final Answer:

   Creates a new public post type called 'book' with title and editor support -> Option C

4. Quick Check:

   register_post_type with public true and supports = A [OK]

Hint: Check 'public' and 'supports' keys for post type behavior [OK]

Common Mistakes:

• Confusing post type with taxonomy
• Assuming missing semicolons cause errors in PHP arrays
• Thinking 'public' false means visible

4. Identify the error in this custom post type registration code:

function create_movie_post_type() {
  register_post_type('movie', [
    'label' => 'Movies',
    'public' => true,
    'supports' => 'title,editor'
  ]);
}
add_action('init', 'create_movie_post_type');

medium

A. The hook 'init' is incorrect for registering post types

B. Missing a closing parenthesis in register_post_type

C. The function name cannot contain underscores

D. 'supports' should be an array, not a string

Solution

1. Step 1: Check the 'supports' argument type

   The 'supports' argument must be an array of features, but here it is a string with comma-separated values.

2. Step 2: Correct the 'supports' argument

   It should be ['title', 'editor'] instead of 'title,editor' to work properly.

3. Final Answer:

   'supports' should be an array, not a string -> Option D

4. Quick Check:

   'supports' requires array format [OK]

Hint: Use array for 'supports', not comma string [OK]

Common Mistakes:

• Passing 'supports' as a string instead of array
• Using wrong hook instead of 'init'
• Incorrect function naming conventions

5. You want to register a custom post type 'event' that is public, supports title, editor, and custom fields, and has a custom menu icon. Which code snippet correctly achieves this?

hard

A. register_post_type('event', ['public' => false, 'supports' => ['title', 'editor'], 'menu_icon' => 'calendar']);

B. register_post_type('event', ['public' => true, 'supports' => ['title', 'editor', 'custom-fields'], 'menu_icon' => 'dashicons-calendar']);

C. register_post_type('event', ['public' => true, 'supports' => 'title,editor,custom-fields', 'menu_icon' => 'dashicons-calendar']);

D. register_post_type('event', ['public' => true, 'supports' => ['title', 'editor'], 'menu_icon' => 'dashicons-event']);

Solution

1. Step 1: Check 'public' and 'supports' keys

   The post type must be public and support title, editor, and custom fields, so 'public' => true and 'supports' => ['title', 'editor', 'custom-fields'] are correct.

2. Step 2: Verify 'menu_icon' value

   The icon must be a valid Dashicons class like 'dashicons-calendar'. register_post_type('event', ['public' => true, 'supports' => ['title', 'editor', 'custom-fields'], 'menu_icon' => 'dashicons-calendar']); uses this correctly.

3. Step 3: Identify errors in other options

   register_post_type('event', ['public' => false, 'supports' => ['title', 'editor'], 'menu_icon' => 'calendar']); sets 'public' false and wrong icon string; register_post_type('event', ['public' => true, 'supports' => 'title,editor,custom-fields', 'menu_icon' => 'dashicons-calendar']); uses string for 'supports'; register_post_type('event', ['public' => true, 'supports' => ['title', 'editor'], 'menu_icon' => 'dashicons-event']); misses 'custom-fields' support.

4. Final Answer:

   register_post_type('event', ['public' => true, 'supports' => ['title', 'editor', 'custom-fields'], 'menu_icon' => 'dashicons-calendar']); -> Option B

5. Quick Check:

   Correct keys and values for event post type [OK]

Hint: Use array for supports and valid dashicons for menu_icon [OK]

Common Mistakes:

• Using string instead of array for 'supports'
• Setting 'public' to false by mistake
• Using invalid icon names