Руководство:Разработка расширений

Каждое расширение состоит из трех частей:

1. Установка
2. Выполнение
3. Локализация

Минимальное расширение будет состоять из следующей структуры:

MyExtension/extension.json

Хранит инструкции установки. Имя файла должно быть extension.json. (До MediaWiki 1.25 инструкции установки находились в файле MyExtension/MyExtension.php с таким же именем, как и у расширения. Многие расширения до сих пор имеют прослойки обратной совместимости в этом PHP файле)

MyExtension/includes/ (or MyExtension/src/)

Хранит исполняемый PHP-код расширения

MyExtension/resources/ (or MyExtension/modules/)

Stores the client-side resources such as JavaScript, CSS and LESS for the extension.

MyExtension/i18n/*.json

Хранит информацию о локализации для расширения.

При разработке расширения замените MyExtension на имя вашего расширения. Используйте имена в стиле UpperCamelCase для директории и PHP файлов; это общее соглашение по именованию файлов. (Расширение BoilerPlate является хорошей отправной точкой для вашего расширения.)

Во время разработки вы можете выключить кэширование настройками $wgMainCacheType = CACHE_NONE и $wgCacheDirectory = false, иначе системные сообщения и другие изменения могут не появляться.

Установка

Your goal in writing the setup portion is to make installing the extension as easy as possible, so users only have to add this line to LocalSettings.php:

wfLoadExtension( 'MyExtension' );

Если вы хотите, чтобы ваше расширение было конфигурируемо, необходимо определить и документировать некоторые параметры конфигурации, и настройки ваших пользователей должны выглядеть следующим образом:

wfLoadExtension( 'MyExtension' );
$wgMyExtensionConfigThis = 1;
$wgMyExtensionConfigThat = false;

Для достижения этой простоты ваш файл установки должен выполнить ряд задач (подробно описано в следующих разделах):

• register any media handlers, parser functions, special pages, custom XML tags, and variables used by your extension.
• определить и/или проверить любые переменные конфигурации, которые вы определили для вашего расширения.
• подготовить классы, используемые вашим расширением, для автозагрузки
• определить, какие части вашей установки должны быть исполнены немедленно, а что должно быть отложено до тех пор, пока ядро ​​MediaWiki не будет инициализировано и сконфигурировано
• определить дополнительные прерывания, требующиеся для вашего расширения
• создать или проверить любые новые таблицы базы данных, необходимые для вашего расширения
• установить локализацию для расширения

Good practice is to add a README file with basic info about how to install and configure the extension. You can use either plain text or Phabricator markup syntax. For example, see the Phabricator Diffusion page for the Расширение:Page Forms . If markdown is used, add the file extension .md. For example, see the README.md file for Parsoid on Phabricator Diffusion.

Регистрирующие функции в MediaWiki

MediaWiki перечисляет все установленные расширения на странице Special:Version. Например, вы можете посмотреть все расширения, установленные на этой вики, на странице Special:Version.

Версия MediaWiki:

≥ 1.25

To do this, add the extension details to extension.json . The entry will look something like this:

{
	"name": "Example",
	"author": "John Doe",
	"url": "https://www.mediawiki.org/wiki/Extension:Example",
	"description": "This extension is an example and performs no discernible function",
	"version": "1.5",
	"license-name": "GPL-2.0-or-later",
	"type": "validextensionclass",
	"manifest_version": 1
}

Многие поля опциональные, но все-таки будет хорошо, если вы их заполните. manifest_version ссылается на схему extension.json файла. The available versions are 1 and 2. See here for the documentation on this feature. Unless you need to support an older version of MediaWiki, pick the latest version.

В дополнение к вышеописанной регистрации вы должны подцепить ваши фичи в MediaWiki. Описанное выше устанавливает только страницу Special:Version. Способ, которым вы это делаете, зависит от типа вашего расширения. Детали смотрите в документации для каждого типа расширения:

Делаем расширение конфигурируемым

Если вы хотите, чтобы пользователь мог настроить ваше расширение, вы должны предоставить некоторые конфигурационные переменные. А также хорошо бы дать этим переменным уникальные имена. Они также должны следовать соглашению по именованию MediaWiki (например, глобальные переменные должны начинаться с $wg).

For example, if your extension is named "MyExtension", you might want to name all your configuration variables to begin with $wgMyExtension. It is important that none of the MediaWiki core begins its variables this way and you have done a reasonable job of checking to see that none of the published extensions begin their variables this way. Users won't take kindly to having to choose between your extension and some other extensions because you chose overlapping variable names.

It is also a good idea to include extensive documentation of any configuration variables in your installation notes.

Here is an example boiler plate that can be used to get started:

{
	"name": "BoilerPlate",
	"version": "0.0.0",
	"author": [
		"Your Name"
	],
	"url": "https://www.mediawiki.org/wiki/Extension:BoilerPlate",
	"descriptionmsg": "boilerplate-desc",
	"license-name": "GPL-2.0-or-later",
	"type": "other",
	"AutoloadClasses": {
		"BoilerPlateHooks": "includes/BoilerPlateHooks.php",
		"SpecialHelloWorld": "includes/SpecialHelloWorld.php"
	},
	"config": {
		"BoilerPlateEnableFoo": {
			"value": true,
			"description": "Enables the foo functionality"
		}
	},
	"callback": "BoilerPlateHooks::onExtensionLoad",
	"ExtensionMessagesFiles": {
		"BoilerPlateAlias": "BoilerPlate.i18n.alias.php"
	},
	"Hooks": {
		"NameOfHook": "BoilerPlateHooks::onNameOfHook"
	},
	"MessagesDirs": {
		"BoilerPlate": [
			"i18n"
		]
	},
	"ResourceModules": {
		"ext.boilerPlate.foo": {
			"scripts": [
				"resources/ext.boilerPlate.js",
				"resources/ext.boilerPlate.foo.js"
			],
			"styles": [
				"resources/ext.boilerPlate.foo.css"
			]
		}
	},
	"ResourceFileModulePaths": {
		"localBasePath": "",
		"remoteExtPath": "BoilerPlate"
	},
	"SpecialPages": {
		"HelloWorld": "SpecialHelloWorld"
	},
	"manifest_version": 2
}

Note that after calling wfLoadExtension( 'BoilerPlate' ); the global variable $wgBoilerPlateEnableFoo does not exist. If you set the variable, e.g. in LocalSettings.php then the default value given in extension.json will not be used.

For more details on how to use global variable inside custom extensions, please refer to Manual:Configuration for developers .

Preparing classes for autoloading

If you choose to use classes to implement your extension, MediaWiki provides a simplified mechanism for helping PHP find the source file where your class is located. In most cases this should eliminate the need to write your own __autoload($classname) method.

To use MediaWiki's autoloading mechanism, you add entries to the AutoloadClasses field. The key of each entry is the class name; the value is the file that stores the definition of the class. For a simple one class extension, the class is usually given the same name as the extension, so your autoloading section might look like this (extension is named MyExtension):

{
	"AutoloadClasses": {
		"MyExtension": "includes/MyExtension.php"
	}
}

The filename is relative to the directory the extension.json file is in.

For more complex extensions, namespaces should be considered. See Manual:Extension.json/Schema#AutoloadNamespaces for details.

Defining additional hooks

See Руководство:Прерывания (хуки) .

Adding database tables

Make sure the extension doesn't modify the core database tables. Instead, extension should create new tables with foreign keys to the relevant MW tables.

Внимание:

If your extension is used on any production WMF-hosted wiki please follow the Schema change guide.

If your extension needs to add its own database tables, use the LoadExtensionSchemaUpdates hook. See the manual page for more information on usage.

Set up localisation

См.:

• Localisation (summary)
• Localisation (detailed)
• Namespaces

Add logs

On MediaWiki, all actions by users on wiki are tracked for transparency and collaboration. See Manual:Logging to Special:Log for how to do it.

Handling dependencies

Assume that an extension requires the presence of another extension, for example because functionalities or database tables are to be used and error messages are to be avoided in case of non-existence.

For example the extension CountingMarker requires the presence of the extension HitCounters for certain functions.

One way to specify this would be by using the requires key in extension.json.

Another option is using ExtensionRegistry (available since MW 1.25):

	if ( ExtensionRegistry::getInstance()->isLoaded( 'HitCounters', '>=1.1' ) {
		/* do some extra stuff, if extension HitCounters is present in version 1.1 and above */
	}

Currently (as of February 2024, MediaWiki 1.41.0) the name of the extension-to-be-checked needs to exactly match the name in their extension.json.

Example: if you want to check the load status of extension "OpenIDConnect", you have to use it with a space

	if ( ExtensionRegistry::getInstance()->isLoaded( 'OpenID Connect' ) {
    ...
	}

Локализация

While developing, you may want to disable both cache by setting $wgMainCacheType = CACHE_NONE and $wgCacheDirectory = false, otherwise your system message changes may not show up.

If you want your extension to be used on wikis that have a multi-lingual readership, you will need to add localisation support to your extension.

Store messages in <language-key>.json

Store message definitions in a localisation JSON file, one for each language key your extension is translated in. The messages are saved with a message key and the message itself using standard JSON format. Each message id should be lowercase and may not contain spaces. Each key should begin with the lowercased extension name. An example you can find in the MobileFrontend extension. Here is an example of a minimal JSON file (in this case en.json):

en.json

{
	"myextension-desc": "Adds the MyExtension great functionality.",
	"myextension-action-message": "This is a test message"
}

Store message documentation in qqq.json

The documentation for message keys can be stored in the JSON file for the pseudo language with code qqq. A documentation of the example above can be:

qqq.json:

{
	"myextension-desc": "The description of MyExtension used in Extension credits.",
	"myextension-action-message": "Adds 'message' after 'action' triggered by user."
}

Load the localisation file

In your extension.json, define the location of your messages files (e.g. in directory i18n/):

{
	"MessagesDirs": {
		"MyExtension": [
			"i18n"
		]
	}
}

Use wfMessage in PHP

In your setup and implementation code, replace each literal use of the message with a call to wfMessage( $msgID, $param1, $param2, ... ). In classes that implement IContextSource (as well as some others such as subclasses of SpecialPage), you can use $this->msg( $msgID, $param1, $param2, ... ) instead. Пример:

wfMessage( 'myextension-addition', '1', '2', '3' )->parse()

Use mw.message in JavaScript

It's possible to use i18n functions in JavaScript too. Look at Manual:API сообщений for details.

Extension types

Extensions can be categorized based on the programming techniques used to achieve their effect. Most complex extensions will use more than one of these techniques:

• Subclassing: MediaWiki expects certain kinds of extensions to be implemented as subclasses of a MediaWiki-provided base class:
  • Служебные страницы – Subclasses of the SpecialPage class are used to build pages whose content is dynamically generated using a combination of the current system state, user input parameters, and database queries. Both reports and data entry forms can be generated. They are used for both reporting and administration purposes.
  • Стили оформления (skins) – Skins change the look and feel of MediaWiki by altering the code that outputs pages by subclassing the MediaWiki class SkinTemplate .
• Прерывания (хуки) – A technique for injecting custom PHP code at key points within MediaWiki processing. They are widely used by MediaWiki's parser, its localization engine, its extension management system, and its page maintenance system.
  • Tag-function associations – XML style tags that are associated with a php function that outputs HTML code. You do not need to limit yourself to formatting the text inside the tags. You don't even need to display it. Many tag extensions use the text as parameters that guide the generation of HTML that embeds Google objects, data entry forms, RSS feeds, excerpts from selected wiki articles.
• Волшебные слова – A technique for mapping a variety of wiki text string to a single id that is associated with a function. Both variables and parser functions use this technique. All text mapped to that id will be replaced with the return value of the function. The mapping between the text strings and the id is stored in the array $magicWords. The interpretation of the id is a somewhat complex process – see Руководство:Волшебные слова for more information.
  • Переменные – Variables are something of a misnomer. They are bits of wikitext that look like templates but have no parameters and have been assigned hard-coded values. Standard wiki markup such as {{PAGENAME}} or {{SITENAME}} are examples of variables. They get their name from the source of their value: a php variable or something that could be assigned to a variable, e.g. a string, a number, an expression, or a function return value.
  • Функции парсера – {{functionname: argument 1 | argument 2 | argument 3...}}. Similar to tag extensions, parser functions process arguments and returns a value. Unlike tag extensions, the result of parser functions is wikitext.
• API modules – You can add custom modules to MediaWiki's action API, that can be invoked by JavaScript, bots or third-party clients.
• Page content models – If you need to store data in formats other than wikitext, JSON, etc. then you can create a new ContentHandler .

Support other core versions

There are two widespread conventions for supporting older versions of MediaWiki core:

• Master: the master branch of the extension is compatible with as many old versions of core as possible. This results in a maintenance burden (backwards-compatibility hacks need to be kept around for a long time, and changes to the extension need to be tested with several versions of MediaWiki), but sites running old MediaWiki versions benefit from functionality recently added to the extension.
• Release branches: release branches of the extension are compatible with matching branches of core, e.g. sites using MediaWiki 1.42 need to use the REL1_42 branch of the extension. (For extensions hosted on Gerrit, these branches are automatically created when new versions of MediaWiki are released.) This results in cleaner code and faster development but users on old core versions do not benefit from bugfixes and new features unless they are backported manually.

Extension maintainers should declare with the compatibility policy parameter of the {{Extension }} template which convention they follow.

Лицензия

MediaWiki is an open-source project and users are encouraged to make any MediaWiki extensions under an Open Source Initiative (OSI) approved license compatible with GPL-2.0-or-later (Wikimedia's standard software license).

We recommend adopting one of the following compatible licenses for your projects in Gerrit:

• GNU General Public License, version 2 or later (GPL-2.0-or-later)
• MIT License (MIT)
• BSD License (BSD-3-Clause)
• Apache License 2.0 (Apache-2.0)

For extensions that have a compatible license, you can request developer access to the MediaWiki source repositories for extensions. To specify the licence in code and with "license-name" a key should be used to provide it's short name, e.g. "GPL-2.0-or-later" or "MIT" adhering to the list of identifiers at spdx.org.

Publishing

To autocategorize and standardize the documentation of your existing extension, please see Шаблон:Extension . To add your new extension to this Wiki:

Разработчик, публикующий свой код в репозитории кода MediaWiki, должен ожидать:

Feedback / Criticism / Code reviews

Review and comments by other developers on things like framework use, security, efficiency and usability.

Developer tweaking

Other developers modifying your submission to improve or clean-up your code to meet new framework classes and methods, coding conventions and translations.

Improved access for wiki sysadmins

If you do decide to put your code on the wiki, another developer may decide to move it to the MediaWiki code repository for easier maintenance. You may then create a Учётная запись разработчика to continue maintaining it.

Future versions by other developers

New branches of your code being created automatically as new versions of MediaWiki are released. You should backport to these branches if you want to support older versions.

Incorporation of your code into other extensions with duplicate or similar purposes — incorporating the best features from each extension.

Credit

Credit for your work being preserved in future versions — including any merged extensions.

Similarly, you should credit the developers of any extensions whose code you borrow from — especially when performing a merger.

Any developer who is uncomfortable with any of these actions occurring should not host in the code repository. You are still encouraged to create a summary page for your extension on the wiki to let people know about the extension, and where to download it.

Deploying and registering

If you intend to have your extension deployed on Wikimedia sites (including possibly Wikipedia), additional scrutiny is warranted in terms of performance and security. Consult Writing an extension for deployment .

If your extension adds namespaces, you may wish to register its default namespaces; likewise, if it adds database tables or fields, you may want to register those at database field prefixes .

Please be aware that review and deployment of new extensions on Wikimedia sites can be extremely slow, and in some cases has taken more than two years.

Help documentation

You should provide public domain help documentation for features provided by your extension. The convention is for extensions to have their user-focused help pages under a pseudo-namespace of Help:Extension:<ExtensionName>, with whatever subpages are required (the top level page will be automatically linked from the extension infobox if it exists). Справка:CirrusSearch is a example of good documentation. You should give users a link to the documentation via the addHelpLink() function.

Releasing updates

There are a number of common approaches to releasing updates to extensions. These are generally defined according to the compatibility policy of the extension (master, rel, or ltsrel):

• master - Releases may be tagged with version numbers on the master branch, and documentation provided on the extension's homepage describing which extension versions are compatible with which core versions. Release branches will still be created automatically, and you may wish to delete these if they are not intended to be used.
• rel and ltsrel - Release by backporting changes to the REL1_* branches (either all changes, or only critical ones). Version numbers are generally not needed unless the extension is a dependency of another (the version number can then be provided in the other extension's configuration to ensure that incompatible combinations aren't installed). Many extensions will stay at the same version number for years.

Providing support / collaboration

Extension developers should open an account on Wikimedia's Фабрикатор , and request a new project for the extension. This provides a public venue where users can submit issues and suggestions, and you can collaborate with users and other developers to triage bugs and plan features of your extension.

См. также

• Руководство:Регистрация расширений - provides further developer documentation on how to register extensions and skins.
• API:Расширения – explains how your extension can provide an API to clients
• Руководство:Расширение вики-разметки
• Руководство:Соглашение по кодированию
• Best practices for extensions
• Загрузчик ресурсов

Learn by example

• Extension:Examples – implements some example features with extensive inline documentation
  • examples git repo with this and other example code
• Extension:BoilerPlate – a functioning boilerplate extension, useful as a starting point for your own extension (git repo)
  • Read the Example extension, base your own code on the BoilerPlate extension.
• cookiecutter-mediawiki-extension – a cookiecutter template which generates a boilerplate extension (with variables etc.)

• • Allows you to get going quickly with your own extension.

• • Can also generate the BoilerPlate extension.
• List of simple extensions - copy specific code from them

References