User capability checks in Wordpress - Mini Project: Build & Apply

User Capability Checks in WordPress

📖 Scenario: You are building a WordPress plugin that shows a special message only to users who have the capability to edit posts. This is common when you want to restrict certain features to editors or administrators.

🎯 Goal: Create a simple WordPress plugin that checks if the current user has the edit_posts capability and displays a message accordingly.

📋 What You'll Learn

Create a function to check user capability

Use the WordPress function current_user_can()

Display a message only if the user can edit posts

Hook the function to the the_content filter to modify post content

💡 Why This Matters

🌍 Real World

Many WordPress sites need to show or hide features based on what the user is allowed to do. This project teaches how to check those permissions safely.

💼 Career

Understanding user capability checks is essential for WordPress developers creating plugins or themes that respect user roles and security.

1

Create the plugin header and basic function

Create a PHP file with the plugin header comment and define a function called show_edit_post_message that accepts one parameter $content. For now, just return the $content unchanged.

Wordpress

<?php
/*
Plugin Name: User Capability Check
Description: Shows a message if user can edit posts.
Version: 1.0
Author: Your Name
*/

function show_edit_post_message($content) {
    // Your code here
    return $content;
}

Need a hint?

Start by creating the plugin header comment and a function that returns the content unchanged.

2

Add a capability check variable

Inside the show_edit_post_message function, create a variable called $can_edit and set it to the result of current_user_can('edit_posts').

Wordpress

<?php
/*
Plugin Name: User Capability Check
Description: Shows a message if user can edit posts.
Version: 1.0
Author: Your Name
*/

function show_edit_post_message($content) {
    $can_edit = current_user_can('edit_posts');
    // Your code here
    return $content;
}

Need a hint?

Use current_user_can('edit_posts') to check if the user can edit posts and store it in $can_edit.

3

Add conditional logic to modify content

Use an if statement to check if $can_edit is true. If yes, append the string '

You can edit posts!

' to the $content variable before returning it.

Wordpress

<?php
/*
Plugin Name: User Capability Check
Description: Shows a message if user can edit posts.
Version: 1.0
Author: Your Name
*/

function show_edit_post_message($content) {
    $can_edit = current_user_can('edit_posts');
    if ($can_edit) {
        // Your code here
    }
    return $content;
}

Need a hint?

Use if ($can_edit) and append the message to $content using .=.

4

Hook the function to the content filter

Add a line after the function to hook show_edit_post_message to the the_content filter using add_filter.

Wordpress

You can edit posts!';
    }
    return $content;
}

// Your code here

Need a hint?

Use add_filter('the_content', 'show_edit_post_message'); to connect your function to WordPress content display.