扩展的最佳实践

本页记录了目前 MediaWiki 的开发扩展的最佳实践。

除非特别说明，否则这些实践也适用于皮肤。

每个项目都有一个评级，以反映其相对重要性。 分级使用 RFC 2119 定义的关键字。 以下是它们在上下文中的含义：

• MUST: 此项是必需的。 仅满足这些条件意味着您的扩展将起作用，但它可能是不可持续的。
• SHOULD: 此项是推荐的。 也满足这些条件意味着扩展将运行良好，并且将来可能会继续运行良好。
• OPTIONAL: 此项是可选的。 我们建议您稍加考虑。 满足这些条件的扩展可以被视为符合我们都渴望的“黄金标准”，并且可以用作其他开发人员的榜样。

工作流程

• MUST: 使用标准问题跟踪器 。 在 Phabricator 中为您的扩展创建或请求创建 项目。
• MUST: 使用标准的 代码审查 系统。
• MUST: 在维基媒体基金会wiki上部署之前 - 通过性能和安全审查 。
• SHOULD: 该扩展应该适合在任何wiki上使用，避免对维基媒体基金会或其他组织的细节进行硬编码。
• SHOULD: 在维基媒体基金会wiki上部署之前 - 将扩展和您的团队添加到维护人员 页面。
• SHOULD: 有共同维护人员！ 至少应该有两个维护人员。 （不一定要是维基媒体基金会的工作人员。）
• OPTIONAL: 创建一个 MediaWiki-Docker 扩展的安装指南。
• OPTIONAL: 为扩展创建一个 MediaWiki-Vagrant 角色。

代码架构

• MUST: Use structured logging, with a channel name specific to your extension and with appropriate use of message severity levels. This aids debugging. For Wikimedia Foundation deployment, this also helps your team in monitoring the extension. See also: Logstash on Wikitech.
• SHOULD: Provide the same functionality through the API (Action API or REST API ) and the graphical interface (index.php).
  • OPTIONAL: The functionality should be implemented without significant code duplication (e.g. shared backend service class with light API and SpecialPage bindings.)
• SHOULD: Use Dependency Injection ("DI") and service classes registered in service wiring.
• SHOULD: Avoid global state, especially singletons or other hidden state via static class variable (unless for debug logs and other state instrisically about the current process and not about any particular wiki or caller). Avoid static calls for anything other than stateless utility methods.
• SHOULD: Avoid use of older unrefactored global or static functions from unrelated classes when writing new DI-based service classes.
• SHOULD: Only throw exceptions for situations that callers should not handle and thus are meant to bubble up.
• SHOULD: Don't hardcode wikitext and assumptions about templates, especially in a way that's not configurable for each website.
• SHOULD: Code should be readable by someone who is familiar in that area.
• SHOULD: Have a clear separation of concerns between what it actually does, and how it is presented to the user.
• SHOULD: Think twice before adding new public APIs that must remain for content compatibility, such as new wikitext syntax functionality.
• SHOULD: Not tightly integrate skin functionality with extension functionality.
• SHOULD: Not add new user preferences , unless you have a really good reason for doing so.
• OPTIONAL: Expose JavaScript methods for use by user scripts and gadgets , and to enable easy debugging from the console.

帮助文档

• MUST: Have an Extension:… page on mediawiki.org.
  • MUST: Add it to the appropriate extension categories .
  • MUST: Explain briefly what it does.
  • MUST: Document provided hooks under Extension:ExtensionName/Hooks/HookName using {{Template:ExtensionHook}} (if any).
  • MUST: List all extensions on which it depends, and how to install and configure those.
  • SHOULD: Set a compatibility policy for your extension in the infobox.
  • SHOULD: Describe all configuration settings in one place, from most-used to most-obscure.
  • OPTIONAL: Mention any similar extensions and explain how it compares and differs to those.
  • OPTIONAL: Write instructions for how to uninstall the extension, or document the limited ability to uninstall.
• MUST: Have a Help:Extension:… page on mediawiki.org if the extension has web-facing user interfaces.
  • OPTIONAL: Add screenshots in multiple languages, and ideally include one in a right-to-left language.
  • OPTIONAL: Mention some edge cases that were tested for – to prove due diligence of not just testing on simple/generic articles.
• SHOULD: Consistently use ‎<code>, ‎<syntaxhighlight>, ‎<kbd>, and ‎<pre> in documentation as appropriate.
• OPTIONAL: Add or update the extension's page on WikiApiary .

File structure

Overall, the extension's file layout should be organized: consistent naming, directory structure that is logical and not messy.

• MUST: Using the following standard directory layout:
  • src/ (when using PSR4 name-spacing, preferred) or includes/: Contains all (and only) PHP classes.
    • i18n files for special page alias, magic words or namespaces located in root folder.
    • SHOULD: Use PSR-4 structure for classes and files, using Extension.json/Schema#AutoloadNamespaces in extension.json instead of listing all classes.
    • SHOULD: Classes in MediaWiki\Extension\<ExtensionName> namespace (or MediaWiki\Skin\<SkinName> if a skin). MediaWiki\<ExtensionName> is permissible if the extension name is a sufficiently unique word and not something generic (e.g. not a verb or noun).
    • SHOULD: One class per file.
  • modules/ (or resources) - Contains JavaScript and CSS for 资源加载器 .
  • maintenance/ command-line maintenance scripts
  • i18n/ - Contains localised messages in JSON files.
  • sql/ - SQL files for database modifications (e.g. called by LoadExtensionSchemaUpdates )
  • tests/:
    • tests/parser/ - Contains parser test files.
    • tests/phpunit/ - Contains PHPUnit test cases.
      • tests/phpunit/unit/ - Contains test cases extending MediaWikiUnitTestCase
      • tests/phpunit/integration/ - Contains test cases extending MediaWikiIntegrationTestCase
    • tests/qunit/ - Contains Qunit test cases.
    • tests/selenium/ - Contains Selenium browser test files.
  • COPYING or LICENSE - Contains full copy of the relevant license the code is released under.
• SHOULD: Avoid having many files in the root level directory.
• SHOULD: Avoid having dozens of nested directories that all only contain one or two things.
• SHOULD: Avoid having very large files, or very many tiny files (but keep following one class per file pattern – many tiny classes may be a sign of something else going wrong).
• SHOULD: Write a README file that summarizes the docs and gives detailed installation instructions.
• SHOULD: Declare foreign resources in a foreign-resources.yaml file.

Database

• MUST: If adding database tables, use the LoadExtensionSchemaUpdates hook to ensure update.php works.
• MUST: Uses the Wikimedia-Rdbms library for all database access. Doing so avoids most SQL injection attack vectors, takes care of ensuring transactional correctness, and follows performance best practices.
• SHOULD: Work well in a distributed environment (concurrency, multiple databases, clustering).
• SHOULD: If it needs persistence, create nice SQL (primary keys, indexes where needed) and uses some caching mechanism where/if necessary.
• SHOULD: Never add fields to the core tables nor alter them in any way. To persist data associated with core tables, create a dedicated table for the extension and reference the core table's primary key. This makes it easier to remove an extension.
• SHOULD: it should use abstract schema .
• OPTIONAL: If the extension persists data and supports uninstalling, provide a maintenance script that automates this (e.g. drop tables, prune relevant log entries and page properties).

Coding conventions

Overall, follow the MediaWiki coding conventions for PHP , JavaScript , CSS , and any other languages that are in-use and have applicable code conventions.

• SHOULD: Run MediaWiki-CodeSniffer to enforce PHP conventions (check CI Entry points ).
• SHOULD: Run Phan for PHP static analysis (check CI Entry points ).
• SHOULD: Run ESLint for JavaScript conventions and static analysis (check CI Entry points ).
• SHOULD: Run Stylelint for CSS conventions (check CI Entry points ).
• SHOULD: Avoid writing all code into one large function (in JavaScript especially).
• OPTIONAL: Use code comments generally to document why the code exists, not what the code does. In long blocks of code, adding comments stating what each paragraph does is nice for easy parsing, but generally, comments should focus on the questions that can't be answered by just reading the code.

Testing

• SHOULD: Have and run PHPUnit and QUnit tests.
  • OPTIONAL: Split out integration and unit tests (see Phab:T87781).
• SHOULD: If there are parser functions or tags, have and run parser tests .
• OPTIONAL: Have and run browser tests .
• OPTIONAL: Test against right-to-left (RTL) languages! (how to verify?).
• OPTIONAL: Test against language converter languages! (how to verify?).

Language

Various aspects of language support are also known as 本地化 (L10n), internationalization (i18n), multlingualization, and globalization. Overall, your extension should be fully usable and compatible with non-English and non-left-to-right languages.

• MUST: Use the proper 本地化 functions (wfMessage ), and not have hardcoded non-translatable strings in your code.
• MUST: Use the standard internationalization systems in MediaWiki.
• MUST: Use a clear and unique prefix named after the extension for all interface messages.
• MUST: Regularly submit messages to, and merge updated translations from, Translatewiki.net . For extensions hosted in Wikimedia Gerrit, translatewiki.net staff will generally proactively do this for you. They start an automatic process which subscribes to new messages from your extension, and also automatically exports and merges updated translations back into your repository once a day. If this hasn't happened within a week, contact TWN staff.
• MUST: Add qqq.json message documentation for all messages that exist in en.json
• SHOULD: lint the message files in CI using banana-checker.
• SHOULD: Escape parameters to localisation messages as close to output as possible. Document whether functions take/accept wikitext vs. HTML.
• OPTIONAL: If an extension uses particular terms, write a glossary of these terms, and link to it from the message documentation. Example: Abstract Wikipedia/Glossary.

Accessibility

Refer to 开发人员的无障碍功能指南 . Note that those are not yet integrated into the guidelines and for the purposes of the extension best practices may be considered as OPTIONAL, pending further discussion.

Security

See also Security for developers .

• MUST: Shelling out should escape arguments.
• MUST: All write actions must be protected against cross-site request forgery (CSRF).
• MUST: Make sure privacy related issues (checkuser, revision and log suppression and deletion) are still covered when refactoring or writing new code.
• SHOULD: Use the standard MediaWiki CSRF token system.
• SHOULD: Don't modify HTML after it has been sanitized (common pattern is to use regex, but that's bad).
• SHOULD: Don't load any resources from external domains. This is also needed for privacy and improves performance.
• SHOULD: Discuss creation of new user rights or user groups with the community first. Adding user rights is easy in code, but must be carefully considered with respect to who may grant these rights, and who carries those rights by default.

TODO: Should extensions be creating user groups in their default configuration? Or should we recommend leaving new rights unassigned or assigned to core groups by default?

Don't reinvent / abuse MediaWiki

As a general principle, do not re-implement or compete with functionality already provided by MediaWiki core.

• MUST: Use MediaWiki functionality/wrappers for things like WebRequest vs. $_GET, etc.
• MUST: Use hooks where possible as opposed to workarounds or novel ways of modifying, injecting, or extending functionality.
• MUST Use MediaWiki's validation/sanitization methods e.g. those in the Html and Sanitizer classes.
• MUST: Don't disable parser cache unless you have a really good reason.
• MUST: Use Composer for 3rd party PHP library management.
• SHOULD: Don't reimplement the wheel. Prefer stable and well-maintained libraries when they exist.
• SHOULD: Don't disable OutputPage . (T140664)
• SHOULD: If an abstraction exists (e.g. Manual:内容处理器 ), use that instead of hooks.
• SHOULD: Don't make things harder for yourself – use standard functionality like extension.json's tests/PHPUnit auto-discovery stuff.
• SHOULD: Use global MediaWiki configuration such as read-only mode.

Uncategorized

• Know when you should use ParserOutput methods vs. similar methods on OutputPage.

Meta

This page was first drafted during the 2017 Wikimania Hackathon.

See also

• API:Client code/Gold standard
• Technical Collaboration Guidance
• w:User:Risker/Risker's checklist for content-creation extensions
• Best practices for using MediaWiki
• phab:T172845 - "What makes a high quality MediaWiki extension?" – Hackathon session