Custom post type arguments in Wordpress - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What is the effect of 'public' => false in a custom post type?

Consider this custom post type registration snippet:

register_post_type( 'book', array( 'public' => false, 'show_ui' => true ) );

What will be the visible behavior in the WordPress admin dashboard?

Wordpress

register_post_type( 'book', array( 'public' => false, 'show_ui' => true ) );

A The post type is hidden both in admin UI and front-end.

B The post type is visible on the front-end but hidden in admin UI.

C The post type is visible both in admin UI and front-end.

D The post type is visible in admin UI but not accessible on the front-end.

💡 Hint

Think about what 'public' controls versus 'show_ui'.

The 'public' argument controls front-end visibility and queryability. Setting it to false hides the post type from front-end queries. However, 'show_ui' controls admin dashboard visibility. Since 'show_ui' is true, the post type appears in admin but not on the front-end.

📝 Syntax

intermediate

Which argument correctly enables REST API support for a custom post type?

You want your custom post type to be accessible via the WordPress REST API. Which argument must be set to true in register_post_type?

Wordpress

register_post_type( 'movie', array( /* arguments here */ ) );

A 'show_in_rest' => true

B 'rest_support' => true

C 'enable_rest' => true

D 'rest_api' => true

💡 Hint

Look for the exact argument name used in WordPress documentation.

The correct argument to enable REST API support is 'show_in_rest'. Setting it to true makes the post type available in the REST API endpoints.

❓ state_output

advanced

What is the slug used in URLs for this custom post type?

Given this registration code:

register_post_type( 'album', array( 'rewrite' => array( 'slug' => 'music' ), 'public' => true ) );

What will be the base URL slug for single 'album' posts?

Wordpress

register_post_type( 'album', array( 'rewrite' => array( 'slug' => 'music' ), 'public' => true ) );

A /music/{post-name}/

B /album/{post-name}/

C /albums/{post-name}/

D /post/{post-name}/

💡 Hint

The 'rewrite' argument controls the URL slug.

The 'rewrite' argument with 'slug' set to 'music' means single posts of this type will have URLs starting with '/music/'.

🔧 Debug

advanced

Why does this custom post type not appear in the admin menu?

This code registers a custom post type but it does not show in the WordPress admin menu:

register_post_type( 'event', array( 'public' => true, 'show_ui' => false ) );

What is the cause?

Wordpress

register_post_type( 'event', array( 'public' => true, 'show_ui' => false ) );

A 'show_in_menu' must be true to appear in admin menu.

B 'show_ui' is false, so admin menu is hidden.

C Missing 'menu_position' argument causes it to be hidden.

D 'public' must be false to show in admin menu.

💡 Hint

Check the meaning of 'show_ui' argument.

The 'show_ui' argument controls whether the post type appears in the admin dashboard menu. Setting it to false hides it from the menu even if 'public' is true.

🧠 Conceptual

expert

Which argument controls whether a custom post type supports hierarchical parent-child relationships?

You want your custom post type to behave like pages, allowing parent and child posts. Which argument enables this?

A 'supports' => ['parent']

B 'parentable' => true

C 'hierarchical' => true

D 'nested' => true

💡 Hint

Think about the argument that controls post relationships.

The 'hierarchical' argument set to true allows the post type to have parent and child posts, similar to pages.

Practice

1. Which argument in register_post_type controls whether the custom post type appears in the WordPress admin menu?

easy

A. public

B. menu_position

C. supports

D. rewrite

Solution

1. Step 1: Understand the role of menu_position

   The menu_position argument sets the location of the custom post type in the WordPress admin menu.

2. Step 2: Compare with other arguments

   public controls visibility on front-end, supports defines features, rewrite controls URL structure.

3. Final Answer:

   menu_position -> Option B

4. Quick Check:

   Admin menu location = menu_position [OK]

Hint: Menu location is set by menu_position argument [OK]

Common Mistakes:

• Confusing public with menu visibility
• Thinking supports controls menu
• Assuming rewrite affects admin menu

2. Which of the following is the correct way to set a custom post type to be publicly queryable in register_post_type arguments?

easy

A. "public_queryable" => true

B. "publiclyqueryable" => true

C. "public_queryable" => "true"

D. "publicly_queryable" => true

Solution

1. Step 1: Recall the exact argument name

   The correct argument is publicly_queryable with an 'ly' and underscore.

2. Step 2: Check value type and spelling

   The value must be boolean true, not string, and spelling must be exact.

3. Final Answer:

   "publicly_queryable" => true -> Option D

4. Quick Check:

   Correct spelling and boolean value = publicly_queryable true [OK]

Hint: Remember 'publicly_queryable' with 'ly' and boolean true [OK]

Common Mistakes:

• Misspelling argument name
• Using string "true" instead of boolean true
• Omitting underscore

3. Given this code snippet, what will be the value of $args['has_archive'] after registration?

$args = [
  'public' => true,
  'has_archive' => false,
  'rewrite' => ['slug' => 'books']
];
register_post_type('book', $args);

medium

A. true

B. null

C. false

D. array with slug 'books'

Solution

1. Step 1: Check the has_archive argument value

   It is explicitly set to false in the array.

2. Step 2: Understand effect of rewrite on has_archive

   The rewrite argument does not override has_archive setting.

3. Final Answer:

   false -> Option C

4. Quick Check:

   Explicit has_archive false remains false [OK]

Hint: Explicit has_archive false stays false despite rewrite [OK]

Common Mistakes:

• Assuming rewrite slug enables archive
• Confusing has_archive with rewrite
• Thinking default true overrides false

4. Identify the error in this register_post_type argument array:

$args = [
  'public' => 'yes',
  'supports' => 'title,editor',
  'menu_icon' => 'dashicons-book'
];
register_post_type('book', $args);

medium

A. 'supports' should be an array, not a comma-separated string

B. 'public' should be boolean true, not string 'yes'

C. 'menu_icon' value is invalid, should be a URL

D. No errors, code is correct

Solution

1. Step 1: Check the supports argument type

   supports must be an array of features, not a string.

2. Step 2: Verify other arguments

   public accepts boolean or string 'true'/'false', 'yes' is invalid but PHP may coerce; menu_icon accepts dashicons slug.

3. Final Answer:

   'supports' should be an array, not a comma-separated string -> Option A

4. Quick Check:

   Supports must be array, not string [OK]

Hint: Supports argument must be an array, not a string [OK]

Common Mistakes:

• Passing supports as string instead of array
• Using invalid string for public
• Thinking menu_icon needs URL

5. You want to create a custom post type 'movie' that is public, supports title and editor, has an archive page at '/films', and appears below Posts in the admin menu. Which $args array is correct?

hard

A. {
'public' => true,
'supports' => ['title', 'editor'],
'has_archive' => true,
'rewrite' => ['slug' => 'films'],
'menu_position' => 5
}

B. {
'public' => true,
'supports' => ['title', 'editor'],
'has_archive' => 'films',
'rewrite' => true,
'menu_position' => 20
}

C. {
'public' => true,
'supports' => 'title,editor',
'has_archive' => true,
'rewrite' => ['slug' => 'movies'],
'menu_position' => 5
}

D. {
'public' => false,
'supports' => ['title', 'editor'],
'has_archive' => true,
'rewrite' => ['slug' => 'films'],
'menu_position' => 5
}

Solution

1. Step 1: Check public visibility and supports

   { 'public' => true, 'supports' => ['title', 'editor'], 'has_archive' => true, 'rewrite' => ['slug' => 'films'], 'menu_position' => 5 } sets public to true and supports as an array with 'title' and 'editor', which is correct.

2. Step 2: Verify archive and rewrite slug

   has_archive is true and rewrite slug is 'films' to get archive at '/films'.

3. Step 3: Confirm menu position

   menu_position 5 places it below Posts in admin menu.

4. Final Answer:

   Option A matches all requirements correctly -> Option A

5. Quick Check:

   Public, supports array, archive slug, menu position 5 = { 'public' => true, 'supports' => ['title', 'editor'], 'has_archive' => true, 'rewrite' => ['slug' => 'films'], 'menu_position' => 5 } [OK]

Hint: Use array for supports, boolean for public, correct slug in rewrite [OK]

Common Mistakes:

• Passing supports as string instead of array
• Setting public false when it should be true
• Incorrect has_archive or rewrite values