How to Use Per Page JavaScript with Conditional Includes in Slater

Slater enables per page JavaScript functionality through the use of conditional includes. This approach allows developers to load specific scripts or stylesheets only on designated pages, optimizing performance and ensuring maintainability.

Published April 14, 2026

Slater offers the ability to include JavaScript and CSS files on specific pages by leveraging conditional logic within your code. This feature is particularly useful for targeting functionality or styles to particular sections of a site without affecting others and improves your site's overall performance.

How Conditional Includes Work

Conditional includes use the current page's URL path to determine which scripts or styles to load. By checking the path, it's possible to import resources only when they are needed.

Example: Structure for Per Page Includes

let paths = window.location.pathname.split('/')

// Global CSS
{
  const link = document.createElement('link');
  link.rel = 'stylesheet';
  link.href = 'https://slater.app/1234/2104.css?v=805038';
  document.head.appendChild(link);
}

// Global JavaScript
import('https://slater.app/1234/51518.js?v=277861')

// About Page JavaScript
{
  const pages = ["about"];
  const path = paths[paths.length - 1]
  const itemPath = paths[paths.length - 2]
  if (
    pages.includes(path) ||
    pages.includes('detail_' + itemPath) ||
    pages.includes(itemPath + '/item')
  ) import('https://slater.app/1234/2089.js?v=572321');
}

Implementation Steps

To implement per page CSS and JS, you should select the page(s) you want the code to run on when creating a new file. You can also later edit which pages your code runs on by selecting the Edit File Settings on the file settings tab.

How this works.

1. Split the URL path:
   • Use window.location.pathname.split('/') to get the segments of the current URL.
2. Define page arrays:
   • List the page slugs where the scripts should be loaded (e.g., ["about"], ["features"]).
3. Check the page context:
   • Compare the current path segment(s) to your page arrays using conditionals.
4. Dynamically import scripts or styles:
   • Use JavaScript's import() or create elements for CSS as needed.

Benefits of Per Page Includes

• Performance: Only necessary resources are loaded, improving load times.
• Maintainability: Code is organized and targeted for specific pages, reducing complexity.
• Flexibility: Easily add or update scripts/styles for individual pages without affecting the global site behavior.

Additional Resources

For more information on modern JavaScript dynamic imports, see MDN Web Docs: import()