How to become a MediaWiki hacker/de



Dieser Artikel soll noch unerfahrenen EntwicklerInnen helfen, die notwendigen Fähigkeiten zu erwerben, um zur MediaWiki-Entwicklung beitragen zu können.

Wenn Sie ein/e erfahrene/r EntwicklerIn sind, besuchen Sie stattdessen .

Überblick
MediaWiki ist die Software, welche Wikipedia, ihre Schwesterprojekte und Tausende von Wikis in der ganzen Welt antreibt. MediaWiki läuft unter den meisten gängigen Betriebssystemen, ist geschrieben in PHP, verwendet primär MySQL Datenbanken und jQuery als Javascript Library für den Browser. Die Entwicklung von MediaWiki wird in erster Linie von der Wikimedia Foundation unterstützt, obwohl freiwillige Community-EntwicklerInnen eine große Rolle spielen.

Diese Seite soll Ihnen zeigen, wie man sich am besten in das Projekt MediaWiki einbringen kann. Es ist kein Lernprogramm, es sind nur Punkte, die Sie zu verschiedenen Orten führen, wo man hingehen kann, um das zu lernen was notwendig ist.

Erste Schritte
Zuallererst, lies dir und das Tutorial von Gerrit durch, bevor du mit dem Runterladen, Testen und Einreichen von Patches beginnst. Dir stehen zwei Möglichkeiten zur Verfügung, um deine Entwicklungsumgebung aufzusetzen: Entweder verwendest du eine vorkonfigurierte virtuelle Maschine (Vagrant) oder du setzt die Entwicklungsumgebung selbststäntig auf.

Virtuelle Maschine mit Vagrant


 * Installation von Vagrant - Eine Step by Step Erklärung für die Installation eines MediaWiki Servers auf einer Linux VM, welche unter Linux, Windows oder Mac OS verwendet werden kann

Manuelle Installation

 * Installationsvorausetzungen - Überprüfe bitte zuerst die Handwarevoraussetzungen und installiere dann einen LAMP, MAMP oder WAMP Server (Linux, Mac oder Windows, inklusive Apache, MySQL und PHP)
 * - Lade den aktuellsten Quellcode von Git herunter
 * - Setze dann mit der Installation und der Erstkonfiguration fort
 * Aktiviere frühzeitig die verschiedenen Debug Varianten in deiner Umgebung um auf Warnungen und Fehler aufmerksam gemacht zu werden

Es ist überhaupt nicht notwendig irgendwelche Wikipedia Datenbank Auszuüge zu generieren, um MediaWiki Features zu erstellen. Eigentlich reicht es vollkommen, eine fast leere Datenbank mit einigen speziellen Testseiten zu verwenden. Falls doch der Fall der Fälle eintrifft, kannst du dir jederzeit einen Wikipedia Datenbank Auszug runterladen.

Zum Einlesen empfohlen
Solltest du an einem Bug Report arbeiten, welcher es nötig macht bestimmten Sourcecode zu schreiben oder zu ändern, solltest du diese Seite unbedingt zuerst lesen:


 * Es gibt zwei empfohlene Wege um mit dem Entwickeln für MediaWiki zu beginnen. Entweder behebt man einen kleinen Bug im bereits bestehendem Code, oder man fügt neue Features hinzu, am besten über eine MediaWiki Erweiterung.
 * Coding conventions and any subpages relevant to your task (,, , …)
 * Following the Commit message guidelines, especially the Example section at the bottom, will automatically add a notification about your patch to the corresponding report in . Hence there is no need anymore to add a "Please review" comment in the report.
 * Check your code against the pre-commit checklist. Don't skip this step ; you'll be happy you didn't.
 * Getting code reviews. Find and add people as potential reviewers of your patch.
 * Amending a change. Don't create a new Gerrit changeset to fix your previous one!
 * In most cases when working with MediaWiki, you do not want to hack MediaWiki core unless you really know what you're doing.

Feedback, questions and support

 * You are expected to do some basic research yourself first: Look at the code, try to get some understanding what it is supposed to do, and try to find the probable place(s) where you need to make changes in order to fix the bug.
 * If you have general questions about infrastructure, the software architecture or workflows which are not tied to the specific bug that you want to work on, use generic channels like, mailing lists, or wiki discussion pages. For example, if you have a problem with Gerrit, the Gerrit discussion page could be a good place to ask.
 * If you have a specific question about the bug itself, comment in the corresponding report. "What do I have to do to fix this bug?" is not a good question to start with: The more specific your questions are, the more likely somebody can answer them quickly. If you have no idea at all how to fix the bug, maybe that bug is not (yet) for you - please consider finding an easier one first.
 * When asking, elaborate what you have tried and found out already, so others can help at the right level. Try to be specific - for example, copy and paste your commands and their output (if not too long) instead of paraphrasing in your own words. This avoids misunderstandings.
 * Avoid private email or support requests in our social media channels.
 * Please be patient when seeking input and comments. On IRC, don't ask to ask, just ask: most questions can be answered by other community members too if you ask on an IRC channel. If nobody answers, please ask on the bug report or wiki page related to the problem; don't just drop the question.
 * Learn more at.

Communicate that you work on a bug
You do not need to be set as the assignee in a bug report or announce your plans before you start working on a bug, but it is welcome. At the latest when you are close to creating a patch for the bug, it is good to announce in a comment that you are working on it. Your announcement also helps others to not work on the bug at the same time and duplicate work.

Also note that if a bug report already has a recent link to a patch in Gerrit and is in the status PATCH_TO_REVIEW, you should choose a different bug to work on instead - avoid duplicating work. If the patch in Gerrit has not been merged and has not seen any changes for a long time, you could also pick up that existing patch and try to improve it.

If you stop working on a task you should remove yourself as the assignee of a bug report and reset the assignee to the default assignee, so others know that they can work on the bug report and don't expect you to still work on it.

By communicating early you will get more attention, feedback and help from community members.

Working on extensions
If you choose to work on MediaWiki extensions code, the following links provide more information.


 * MediaWiki extensions primers:
 * Developing extensions — How to write an extension for MediaWiki.
 * Writing an extension for deployment — If you intend to have your extension deployed on Wikimedia sites (including possibly Wikipedia), additional scrutiny is warranted in terms of performance and security.
 * Extension writing tutorial


 * MediaWiki extensions resources:
 * List of simple extensions — A simple way to become more familiar with how extensions work.
 * A brief introduction to MediaWiki extension development — A video presentation about how to create a MediaWiki extension (slides).
 * Making a MediaWiki extension — Covers how to develop an extension for Mediawiki, best practices, and how to engage the Mediawiki community. From February 2011.
 * Special page template — Add a special page to display some handy information.
 * Extending wiki markup — Add a parser hook to modify the content of wikitext.

PHP
MediaWiki is written in PHP, so you'll need to get familiar with PHP to hack MediaWiki's core.


 * Learn PHP
 * PHP tutorial — Available in many different languages. If you have no knowledge of PHP but know how to program in other object-oriented programming languages, PHP will be easy for you to learn.
 * PHP Programming at Wikibooks.
 * PHP topic at Wikiversity.


 * PHP resources:
 * The PHP manual — Available in many different languages.
 * PHP coding conventions within the MediaWiki community.


 * Stuff to know:
 * The script  in MediaWiki provides a basic PHP interpreter with MediaWiki objects and classes loaded.

Database
Many features require some amount of database manipulation, so you'll often need to be familiar with MySQL.


 * Learn MySQL
 * MySQL tutorial — From the MySQL 5.0 reference manual.
 * MySQL at Wikibooks.


 * MySQL resources
 * MySQL Reference Manuals — Available in many different languages.
 * Database coding conventions within the MediaWiki community.


 * Stuff to know:
 * Test your code with MySQL.
 * MediaWiki currently uses MySQL (and compatible ones) as the primary database back-end. It also supports other DBMSes, such as PostgreSQL and SQLite. However, almost all developers use MySQL and don't test other DBs, which consequently break on a regular basis. You're therefore advised to use MySQL when testing patches, unless you're specifically trying to improve support for another DB. In the latter case, make sure you're careful not to break MySQL (or write queries that are horribly inefficient in it), since MySQL is what everybody else uses.

JavaScript and CSS
JavaScript and CSS have become omnipresent in front-end code. You don't have to be familiar with JavaScript, jQuery and CSS to work on MediaWiki, but you might need to, depending on what you choose to work on.


 * Learn JavaScript and CSS
 * JavaScript and CSS at Wikibooks.
 * Getting Started with jQuery — A jQuery tutorial.


 * JavaScript and CSS resources
 * JavaScript coding conventions within the MediaWiki community.
 * CSS coding conventions within the MediaWiki community.

MediaWiki
The MediaWiki code base is large and some parts are ugly; don't be overwhelmed by it. When you're first starting off, aim to write features or fix bugs which are constrained to a small region of code.


 * MediaWiki primers and must-reads:
 * MediaWiki architecture — A high-level overview of the main components of MediaWiki and how they work with each other.
 *  — An overview of why and how to write secure code.


 * MediaWiki resources:
 * — A list of important files and links to more detailed information.
 * — A list of hooks. If you're trying to find what part of the codebase does something, often a good place to start is by searching for the related hooks.
 * — An overview of general coding conventions within the MediaWiki community.
 * Intro-to-MediaWiki workshop syllabus — Ways to hack MediaWiki, from user preferences to extensions and core.
 * Code documentation — Automatically generated documentation from the code and code comments.
 * — A guide to debugging MediaWiki.
 * — A tool to interact with MediaWiki objects live.