# FolderWeb

Minimal file-based CMS. Folders = URLs. PHP 8.4+, no JS, no frameworks, no build tools.

## Philosophy

Decade-scale maintainability. Only essential tech. Readable, simple, future-proof. No volatile dependencies.

## Two Modes of Work

1. **Building on top** (`custom/`): Create sites using the framework. Never modify `app/`. In this mode, `app/` is typically symlinked or submoduled from the framework repo into a separate site repo.
2. **Framework development** (`app/`): Evolve the core. Preserve all stable contracts (see architecture doc). `custom/` may be symlinked in from a site repo for testing.

## Core Constraints

- **Stack:** HTML5, PHP 8.4+, CSS. Nothing else.
- **Frontend:** Classless semantic HTML, modern CSS (nesting, `oklch()`, grid, `clamp()`, logical props)
- **Security:** Path traversal protection, document root restriction, strict MIME types, escape all UGC

## Code Style

- **PHP:** Arrow functions, null coalescing, match expressions. Type hints where practical. Single-purpose functions. Comments only for major sections.
- **CSS:** Variables, native nesting, grid. `clamp()` over `@media`. Relative units.
- **Templates:** `<?= htmlspecialchars($var) ?>` for UGC. `<?= $content ?>` for pre-rendered HTML.

## Knowledge Base

Read these docs on-demand when working on related areas. Do not load all at once.

| Skill | File | Read When |
|---|---|---|
| Architecture | `docs/04-development/01-architecture.md` | Understanding project structure, request flow, module dependencies, stable contracts |
| Content System | `docs/04-development/02-content-system.md` | Working with routing, URL resolution, metadata, content discovery, navigation |
| Configuration | `docs/04-development/03-configuration.md` | Config loading, the `custom/` override system, static asset routing |
| Context API | `docs/04-development/04-context-api.md` | The Context class, Templates class, built-in context keys |
| Hooks & Plugins | `docs/04-development/05-hooks-plugins.md` | Hook system, plugin manager, writing plugins, the language plugin |
| Templates | `docs/04-development/06-templates.md` | Template hierarchy, resolution, variables, list item schema, partials |
| Rendering | `docs/04-development/07-rendering.md` | Rendering pipeline, Markdown caching, static file serving, Parsedown |
| Dev Environment | `docs/04-development/08-dev-environment.md` | Container setup, Apache config, performance profiling, test data generation |

Human-facing docs (tutorials, reference) are in `docs/01-getting-started/`, `docs/02-tutorial/`, `docs/03-reference/`.