Horizon Code

1. Problem Statement

When you are already building full applications in pure JavaScript, but want the interface to look modern, respond quickly, and work without page reloads, difficulties often arise with state management, component reuse, and efficient DOM updates. You’re not alone — at this stage, many look for ways to make code more organized, scalable, and convenient for further development.

2. Solution

Horizon Code is a set of materials that helps master the principles of building modern single-page-like applications (SPA-like) without frameworks. Here you study state management, component approach, pure JS routing, advanced form handling, and build several complex projects with clear architecture and good performance.

3. What's Inside

• Module 1: State Management without External Libraries — Building a simple custom state manager (publish-subscribe), centralized store, reactive DOM updates on data changes.
• Module 2: Component Approach in Pure JS — Creating reusable components (classes or functions), passing props, events between components, mount/unmount.
• Module 3: Routing without Reload — Browser history (pushState, replaceState), hash routing, dynamic content loading based on URL, basic SPA router.
• Module 4: Advanced Forms — Custom validation, input masks, dynamic fields (add/remove), handling large forms, draft saving in localStorage.
• Module 5: Performance & Optimization — Virtual DOM-like approach (diffing), debounce/throttle, memoization, avoiding reflow/repaint, lazy loading components and data.
• Module 6: Complex Practical Projects — Three full examples: • Multi-page dashboard: authorization (simulation), routing, sidebar, dynamic tables with sorting/filtering/pagination, user state. • Habit tracker: calendar, add/edit habits, period statistics, progress chart (Canvas or SVG), data persistence. • E-commerce prototype (no backend): product catalog with filters, cart, real-time updates, state in localStorage, checkout form.
• Module 7: Testing & Code Documentation — Writing simple manual tests for components and functions, documenting code (JSDoc), creating READMEs for projects.

4. Who is this for?

✅ Suitable if you...

• are already building interactive apps with API and localStorage;
• want to understand how modern SPAs work under the hood;
• want to write scalable projects without framework dependency;
• are ready for large structured applications with routing and state.

❌ Not suitable if you...

• are not yet confident with async JS and DOM manipulations (better Vertex Echo);
• already use React, Vue or Svelte on a regular basis and are looking for deep specialization in them.

5. What You'll Learn 

• How to implement a simple custom state manager with reactive updates;
• How to create and use reusable components in pure JavaScript;
• How to organize client-side routing with history API or hash;
• How to build complex forms with dynamic fields and validation;
• How to optimize rendering and avoid unnecessary DOM updates;
• How to create multi-page interfaces with panels, tables, and charts;
• How to persist and restore app state between reloads;
• How to write basic tests for logic and components;
• How to document your code and projects for better future maintainability.

9. Guarantee

• 30-day money back
  
• Risk-free