redaxo-architecture

REDAXO Architecture

REDAXO is a PHP CMS organized around a small core plus addons. Almost every feature lives in an addon – including structure (articles/categories), mediapool (media management), users, and cronjob.

Directory layout

redaxo/
├── src/
│   ├── core/              # Core classes (rex_*, never edit)
│   └── addons/
│       ├── structure/     # Articles & categories
│       ├── mediapool/     # Media library
│       ├── users/         # Backend user management
│       └── <your-addon>/  # Custom addons live here
├── data/
│   ├── addons/            # Addon-managed runtime data
│   ├── core/              # Core runtime data (config.yml lives here)
│   └── log/               # System logs
└── cache/                 # Generated files; safe to delete

The user's project root usually contains redaxo/ plus assets/ (public mirror of addon assets) and a frontend directory (often public/ or root).

Request lifecycle (high level)

1. index.php boots rex (frontend) or redaxo/index.php boots the backend.
2. Core loads config.yml and the package.yml of every installed addon.
3. Each addon's boot.php runs – this is where extension points get registered.
4. For frontend requests: structure resolves the article via URL → loads template → executes modules.
5. OUTPUT_FILTER runs on the final HTML before it's sent.

Key core classes

• rex_addon::get('addon_name') – access addon instance, config, paths, version
• rex_config::get('namespace', 'key', $default) / set() – persistent key-value config
• rex_path::addon('addon_name', 'sub/path') – absolute filesystem paths
• rex_path::frontend('relative/path') – paths in the public frontend
• rex_url::backendController(['page' => 'addon/section']) – backend URLs
• rex_url::frontendController(['article_id' => 5]) – frontend URLs (use yrewrite if installed)
• rex_clang::getCurrentId() / rex_clang::getAll() – language handling
• rex_request::get('key', 'string', '') / post() – type-safe input
• rex_response::sendJson($data) – JSON responses for AJAX
• rex_logger::factory()->log('error', $msg) – write to system log
• rex::isBackend() / rex::isFrontend() / rex::getUser() – context

Conventions

• Never edit core files. Hook into the system via extension points or override via your own addon.
• Addon code goes in redaxo/src/addons/<name>/ during development; published addons get distributed via the REDAXO Installer or redaxo.org.
• Public assets are placed in your addon's assets/ folder. They're symlinked/copied to assets/addons/<name>/ on install.
• For paths, always use rex_path::* instead of hardcoding __DIR__ . '/../...'.
• For URLs, always use rex_url::* so the system stays portable across installations and subdirectory deployments.

Common pitfalls

• Forgetting rex::isBackend() checks in boot.php – many extension points fire in both contexts.
• Using $_GET / $_POST directly instead of rex_request – loses type safety and the built-in CSRF token handling.
• Hardcoding language IDs (assuming 1 = German). Use rex_clang::getCurrent() and rex_clang::getCurrentId().