User capability checks in Wordpress - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to check if the current user can edit posts.

Wordpress

<?php if (current_user_can([1])) { echo 'User can edit posts'; } ?>

Drag options to blanks, or click blank then click option'

A'edit_posts'

B'manage_options'

C'publish_posts'

D'delete_posts'

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'manage_options' which is for admin settings.

Using 'publish_posts' which checks publishing rights, not editing.

The current_user_can('edit_posts') function checks if the user has permission to edit posts.

2fill in blank

medium

Complete the code to check if the current user can delete pages.

Wordpress

<?php if (current_user_can([1])) { echo 'User can delete pages'; } ?>

Drag options to blanks, or click blank then click option'

A'edit_pages'

B'publish_pages'

C'delete_pages'

D'read_pages'

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'edit_pages' which checks editing, not deleting.

Using 'publish_pages' which checks publishing rights.

The current_user_can('delete_pages') function checks if the user can delete pages.

3fill in blank

hard

Fix the error in the code to correctly check if the user can manage options.

Wordpress

<?php if (current_user_can([1])) { echo 'User can manage options'; } ?>

Drag options to blanks, or click blank then click option'

A'manage_options'

B'manage_option'

C'manage_optionss'

D'manage'

Attempts:

3 left

💡 Hint

Common Mistakes

Misspelling the capability string.

Using singular form instead of plural.

The correct capability to check for managing options is 'manage_options'.

4fill in blank

hard

Fill both blanks to check if the user can edit a specific post with ID 42.

Wordpress

<?php if (current_user_can([1], [2])) { echo 'User can edit this post'; } ?>

Drag options to blanks, or click blank then click option'

A'edit_post'

B42

C'edit_posts'

D24

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'edit_posts' which checks general post editing, not a specific post.

Using wrong post ID.

Use current_user_can('edit_post', 42) to check if the user can edit the post with ID 42.

5fill in blank

hard

Fill all three blanks to check if the user can publish a post of type 'book'.

Wordpress

<?php if (current_user_can([1], [2], [3])) { echo 'User can publish book'; } ?>

Drag options to blanks, or click blank then click option'

A'publish_post'

B'book'

C0

D'publish_books'

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'publish_post' which is singular and generic.

Using wrong post type string.

Omitting the third argument.

The capability publish_books checks if the user can publish posts of type 'book'. The third argument 0 is often used as a placeholder for post ID when not needed.

Practice

1. What is the main purpose of the current_user_can() function in WordPress?

easy

A. To check if the current user has a specific capability

B. To create a new user role

C. To delete a user from the database

D. To update the user's profile information

Solution

1. Step 1: Understand the function's role

   current_user_can() is designed to check permissions for the current user.

2. Step 2: Identify correct usage

   It returns true if the user has the capability passed as an argument, otherwise false.

3. Final Answer:

   To check if the current user has a specific capability -> Option A

4. Quick Check:

   Permission check = A [OK]

Hint: Remember: current_user_can checks permissions, not user creation [OK]

Common Mistakes:

• Confusing capability check with user creation
• Thinking it modifies user data
• Assuming it deletes users

2. Which of the following is the correct syntax to check if the current user can edit posts?

easy

A. current_user_can(edit_posts);

B. current_user_can['edit_posts'];

C. current_user_can('edit_posts');

D. current_user_can->edit_posts();

Solution

1. Step 1: Identify correct function call syntax

   WordPress functions use parentheses and string arguments in quotes.

2. Step 2: Check each option

   Only current_user_can('edit_posts'); uses parentheses and quotes correctly.

3. Final Answer:

   current_user_can('edit_posts'); -> Option C

4. Quick Check:

   Function call with string argument = B [OK]

Hint: Use parentheses and quotes for capability strings [OK]

Common Mistakes:

• Omitting quotes around capability
• Using square brackets instead of parentheses
• Using arrow notation incorrectly

3. What will the following code output if the current user cannot delete posts?

if (current_user_can('delete_posts')) {
  echo 'Can delete posts';
} else {
  echo 'Cannot delete posts';
}

medium

A. Can delete posts

B. No output

C. Error: function not found

D. Cannot delete posts

Solution

1. Step 1: Understand the condition

   The if checks if the user has 'delete_posts' capability.

2. Step 2: Evaluate the condition result

   If the user cannot delete posts, the condition is false, so the else block runs.

3. Final Answer:

   Cannot delete posts -> Option D

4. Quick Check:

   False condition triggers else = D [OK]

Hint: If user lacks capability, else block runs [OK]

Common Mistakes:

• Assuming output is always 'Can delete posts'
• Confusing capability names
• Expecting errors if capability missing

4. Identify the error in this code snippet:

if (current_user_can('edit_post')) {
  echo 'User can edit post';
}

medium

A. Missing semicolon after echo statement

B. The capability name should be 'edit_posts' not 'edit_post'

C. current_user_can() requires two arguments

D. The function should be called as currentUserCan()

Solution

1. Step 1: Check capability name correctness

   WordPress uses 'edit_posts' (plural) as the capability, not 'edit_post'.

2. Step 2: Verify syntax and function usage

   Semicolon is present, function takes one argument, and function name is correct.

3. Final Answer:

   The capability name should be 'edit_posts' not 'edit_post' -> Option B

4. Quick Check:

   Correct capability string = A [OK]

Hint: Check exact capability names in WordPress docs [OK]

Common Mistakes:

• Using singular instead of plural capability names
• Assuming function needs multiple arguments
• Incorrect function name casing

5. You want to show a special admin menu only to users who can manage options and edit themes. Which code correctly checks both capabilities before showing the menu?

hard

A. if (current_user_can('manage_options') && current_user_can('edit_themes')) { show_menu(); }

B. if (current_user_can('manage_options' || 'edit_themes')) { show_menu(); }

C. if (current_user_can(['manage_options', 'edit_themes'])) { show_menu(); }

D. if (current_user_can('manage_options') || current_user_can('edit_themes')) { show_menu(); }

Solution

1. Step 1: Understand logical AND for both capabilities

   To require both permissions, use && between two separate current_user_can() calls.

2. Step 2: Evaluate each option's logic

   if (current_user_can('manage_options') && current_user_can('edit_themes')) { show_menu(); } correctly uses && with two calls; A and B misuse syntax; D uses || which allows either permission.

3. Final Answer:

   if (current_user_can('manage_options') && current_user_can('edit_themes')) { show_menu(); } -> Option A

4. Quick Check:

   Both capabilities require && = C [OK]

Hint: Use && with separate calls to check multiple capabilities [OK]

Common Mistakes:

• Using || instead of && when both permissions are needed
• Passing multiple capabilities as one argument
• Using incorrect syntax for logical operators