Using Hooks and Filters

This guide provides detailed instructions on how to customize LearnPress functionality using hooks and filters without modifying the core plugin files.

Understanding Hooks and Filters

WordPress and LearnPress use a system of hooks and filters to allow developers to modify functionality and appearance:

• Action Hooks – Allow you to add custom content or functionality at specific points in the code
• Filter Hooks – Allow you to modify data or content before it’s displayed or processed

Action Hooks

Action hooks allow you to add custom content or functionality at specific points in the LearnPress templates.

How to Use Action Hooks

To use an action hook, add a function to your theme’s functions.php file and hook it to a specific action:

// Add to functions.php
function my_custom_function() {
    // Your code here
    echo 'This is my custom content';
}
add_action('learn-press/hook-name', 'my_custom_function');

Common Action Hooks

Practical Examples

// Add to functions.php
function my_custom_before_course_content() {
    echo '<div class="my-custom-notice">';
    echo 'This course has been updated on ' . date('F j, Y') . '.';
    echo '</div>';
}
add_action('learn-press/before-course-content', 'my_custom_before_course_content');

// Add to functions.php
function my_custom_after_checkout_message() {
    echo '<div class="checkout-guarantee">';
    echo '<i class="fas fa-shield-alt"></i> ';
    echo 'We offer a 30-day money-back guarantee on all courses.';
    echo '</div>';
}
add_action('learn-press/after-checkout-form', 'my_custom_after_checkout_message');

// Add to functions.php
function add_social_sharing_buttons() {
    global $post;
    
    // Only show on course pages
    if (get_post_type() !== LP_COURSE_CPT) {
        return;
    }
    
    $share_url = urlencode(get_permalink());
    $share_title = urlencode(get_the_title());
    
    echo '<div class="course-social-sharing">';
    echo '<h4>Share this course:</h4>';
    echo '<a href="https://www.facebook.com/sharer/sharer.php?u=' . $share_url . '" target="_blank" class="facebook-share"><i class="fab fa-facebook-f"></i> Facebook</a>';
    echo '<a href="https://twitter.com/intent/tweet?url=' . $share_url . '&text=' . $share_title . '" target="_blank" class="twitter-share"><i class="fab fa-twitter"></i> Twitter</a>';
    echo '<a href="https://www.linkedin.com/shareArticle?mini=true&url=' . $share_url . '&title=' . $share_title . '" target="_blank" class="linkedin-share"><i class="fab fa-linkedin-in"></i> LinkedIn</a>';
    echo '</div>';
}
add_action('learn-press/after-course-content', 'add_social_sharing_buttons');

Filter Hooks

Filter hooks allow you to modify data or content before it’s displayed or processed.

How to Use Filter Hooks

To use a filter hook, add a function to your theme’s functions.php file and hook it to a specific filter:

// Add to functions.php
function my_custom_filter_function($content) {
    // Modify $content here
    $content = 'Modified: ' . $content;
    return $content;
}
add_filter('learn-press/filter-name', 'my_custom_filter_function');

Common Filter Hooks

Practical Examples

// Add to functions.php
function my_custom_course_price_html($price_html, $course) {
    // Add a "Limited Time Offer" text for courses with sale price
    if ($course->has_sale_price()) {
        $price_html = '<span class="limited-offer">Limited Time Offer!</span> ' . $price_html;
    }
    return $price_html;
}
add_filter('learn-press/course-price-html', 'my_custom_course_price_html', 10, 2);

// Add to functions.php
function add_custom_course_tab($tabs, $course) {
    // Add a new "Resources" tab
    $tabs['resources'] = array(
        'title'    => __('Resources', 'your-text-domain'),
        'priority' => 40,
        'callback' => 'display_course_resources_tab'
    );
    return $tabs;
}
add_filter('learn-press/course-tabs', 'add_custom_course_tab', 10, 2);

// Callback function to display tab content
function display_course_resources_tab() {
    // Get the current course
    $course = LP_Global::course();
    
    // Display content
    echo '<h3>Course Resources</h3>';
    echo '<ul>';
    echo '<li><a href="#">Resource 1</a></li>';
    echo '<li><a href="#">Resource 2</a></li>';
    echo '<li><a href="#">Resource 3</a></li>';
    echo '</ul>';
    
    // You can also get custom field data if you've added any
    // $resources = get_post_meta($course->get_id(), '_course_resources', true);
}

// Add to functions.php
function add_custom_course_type($filter_types) {
    // Add a new course type "Blended"
    $filter_types['blended'] = __('Blended', 'your-text-domain');
    return $filter_types;
}
add_filter('learn-press/filter-courses/type/fields', 'add_custom_course_type');

// Add to functions.php
function customize_profile_tabs($tabs, $user) {
    // Rename existing tab
    if (isset($tabs['courses'])) {
        $tabs['courses']['title'] = __('My Learning Path', 'your-text-domain');
    }
    
    // Add new tab
    $tabs['achievements'] = array(
        'title'    => __('Achievements', 'your-text-domain'),
        'priority' => 40,
        'callback' => 'display_user_achievements_tab'
    );
    
    // Remove a tab
    if (isset($tabs['settings'])) {
        unset($tabs['settings']);
    }
    
    return $tabs;
}
add_filter('learn-press/profile-tabs', 'customize_profile_tabs', 10, 2);

// Callback function for the new tab
function display_user_achievements_tab() {
    $user = LP_Profile::instance()->get_user();
    echo '<h3>Your Achievements</h3>';
    // Display achievements content
}

Advanced Customization with Hooks

Modifying Course Query

You can modify how courses are queried using the learn-press/query/course-args filter:

// Add to functions.php
function modify_course_query_args($args) {
    // Only show courses from a specific category
    $args['tax_query'] = array(
        array(
            'taxonomy' => 'course_category',
            'field'    => 'slug',
            'terms'    => 'featured-courses',
        ),
    );
    
    // Change the number of courses per page
    $args['posts_per_page'] = 12;
    
    return $args;
}
add_filter('learn-press/query/course-args', 'modify_course_query_args');

Customizing Enrollment Process

You can customize the enrollment process using various hooks:

// Add to functions.php
function custom_after_enrollment_actions($course_id, $user_id, $user_course) {
    // Send a custom email
    $user = get_user_by('id', $user_id);
    $course = learn_press_get_course($course_id);
    
    $subject = 'Welcome to ' . $course->get_title();
    $message = 'Hi ' . $user->display_name . ',\n\n';
    $message .= 'Thank you for enrolling in ' . $course->get_title() . '.\n';
    $message .= 'Here are some resources to help you get started:\n';
    $message .= '- Course overview: ' . get_permalink($course_id) . '\n';
    $message .= '- Our student community: https://example.com/community\n\n';
    $message .= 'Happy learning!\n';
    
    wp_mail($user->user_email, $subject, $message);
    
    // Add user to a specific group
    // Your custom code here
}
add_action('learn-press/user-enrolled-course', 'custom_after_enrollment_actions', 10, 3);

Customizing Quiz Behavior

You can customize quiz behavior using various hooks:

// Add to functions.php
function custom_quiz_result_message($message, $quiz, $user, $attempt) {
    $result = $attempt->get_results();
    $percent = $result['result'];
    
    if ($percent >= 90) {
        $message = 'Excellent work! You scored ' . $percent . '%. You have mastered this topic!';
    } elseif ($percent >= 70) {
        $message = 'Good job! You scored ' . $percent . '%. You have a solid understanding of this topic.';
    } elseif ($percent >= 50) {
        $message = 'You scored ' . $percent . '%. You have a basic understanding, but might need to review some concepts.';
    } else {
        $message = 'You scored ' . $percent . '%. We recommend reviewing the material and trying again.';
    }
    
    return $message;
}
add_filter('learn-press/quiz/result-message', 'custom_quiz_result_message', 10, 4);

Working with the New Features

Customizing Online/Offline Course Filters

With the new online/offline course filter feature, you can customize how courses are filtered:

// Add to functions.php
function modify_course_type_labels($filter_types) {
    // Change the labels
    if (isset($filter_types['online'])) {
        $filter_types['online'] = __('Virtual Learning', 'your-text-domain');
    }
    
    if (isset($filter_types['offline'])) {
        $filter_types['offline'] = __('In-Person Classes', 'your-text-domain');
    }
    
    return $filter_types;
}
add_filter('learn-press/filter-courses/type/fields', 'modify_course_type_labels');

Customizing Profile Page Pagination

With the recent updates to pagination for quizzes on the profile page, you can customize the pagination settings:

// Add to functions.php
function modify_profile_quizzes_pagination($args) {
    // Change number of quizzes per page
    $args['per_page'] = 10;
    
    return $args;
}
add_filter('learn-press/profile/quizzes/query-args', 'modify_profile_quizzes_pagination');

Best Practices

1. Use a child theme for your customizations to prevent losing changes during theme updates
2. Prefix your function names to avoid conflicts with other plugins
3. Check hook parameters to ensure you’re using the correct number and types of parameters
4. Test thoroughly after LearnPress updates to ensure your customizations still work
5. Use conditional logic to ensure your code only runs when needed

Conclusion

By using hooks and filters, you can extensively customize LearnPress functionality without modifying the core plugin files. This approach ensures that your customizations will not be lost when updating the plugin.