Core Development¶

Welcome to the MeetAgain core development guide. This section covers everything you need to contribute to the core application — from understanding the layer architecture to writing tests and following code conventions.

What's in the core¶

MeetAgain is organized into distinct subsystems. Each is self-contained and communicates through services and repositories:

Subsystem	Directory	Description
Events	`src/Entity/Event*`, `src/Service/EventService.php`	Event creation, RSVP, recurring rules, comments
CMS	`src/Entity/Cms*`, `src/Service/CmsService.php`	Content pages, blocks, menu locations
Members	`src/Entity/User.php`, `src/Service/MemberService.php`	User profiles, membership status
Users & Auth	`src/Security/`, `src/Controller/SecurityController.php`	Login, registration, roles
Email	`src/Entity/EmailTemplate*`, `src/Service/EmailService.php`	Template-based transactional email
Config	`src/Entity/Config.php`, `src/Service/ConfigService.php`	Key/value application settings
Plugin System	`src/Plugin.php`, `src/Filter/`	Plugin interface, filter contracts
Activity Log	`src/Entity/Activity.php`, `src/Service/ActivityService.php`	Audit trail of user actions
Announcements	`src/Entity/Message.php`	Site-wide announcements
Translations	`translations/`, `src/Service/TranslationService.php`	EN/DE/CN YAML translation files
Hosts	`src/Entity/Host.php`, `src/Service/HostService.php`	Event host/organizer groups

Architecture at a glance¶

The application follows a strict four-layer architecture:

Controller  →  Service  →  Repository  →  Entity
(HTTP/CLI)     (logic)     (DB access)    (data)

Layer	Responsibility
Controller	Thin HTTP/CLI entry points; delegates to services; no business logic
Service	Business logic; `readonly` classes; uses repositories and other services
Repository	Data access; QueryBuilder methods with intent-revealing names
Entity	Plain Doctrine-mapped objects; no logic; enums for domain values

Dependencies flow downward only. A repository never calls a service; a service never calls a controller.

See Architecture for the full dependency rules and plugin system.

Contributor journey¶

Set up the dev environment → Getting Started
Understand the layer rules → Architecture
Read the patterns for the area you're changing → Patterns
Check frontend conventions if touching templates → Frontend
Write tests → Testing
Run just fixMago then just test — must be green before opening a PR
Open a PR → Contributing

Quick links¶

Page	What it covers
Architecture	Layer rules, plugin system, Symfony events, directory tour
Patterns	Service, Repository, Entity, Form, Command code examples
Frontend	Twig templates, Bulma CSS, admin UI, translations
Data Fixtures	AbstractFixture, cross-references, fixture groups
Testing	AAA pattern, test doubles, functional tests, running tests
Best Practices	Readonly services, N+1, enums, HTML sanitization
Troubleshooting	Common problems and how to fix them