silverstripe-framework/docs/en/02_Developer_Guides/05_Extending/00_Modules.md

title	summary	icon
Modules	Extend core functionality with modules.	code

Modules

SilverStripe is designed to be a modular application system - even the CMS is simply a module that plugs into the core framework.

A module is a collection of classes, templates, and other resources that is loaded into a directory. Modules are Composer packages, and are placed in the vendor/ folder. These packages need to contain either a toplevel _config directory or _config.php file, as well as a special type in their composer.json file (example).

app/
|
+-- _config/
+-- src/
+-- ..
|
vendor/my_vendor/my_module/
|
+-- _config/
+-- composer.json
+-- ...

Like with any Composer package, we recommend declaring your PHP classes through PSR autoloading. SilverStripe will automatically discover templates and configuration settings within your module when you next flush your cache.

Finding Modules

• Official module list on silverstripe.org
• Packagist.org "silverstripe" tag
• GitHub.com "silverstripe" search

Installation

Modules are installed through the Composer package manager. It enables you to install modules from specific versions, checking for compatibilities between modules and even allowing to track development branches of them. To install modules using this method, you will first need to setup SilverStripe with Composer.

Each module has a unique identifier, consisting of a vendor prefix and name. For example, the "blog" module has the identifier silverstripe/blog as it is published by silverstripe. To install, use the following command executed in the root folder:

composer require silverstripe/blog *@stable

This will fetch the latest compatible stable version of the module. To install a specific version of the module give the tag name.

composer require silverstripe/blog 1.1.0

Composer is using version constraints. To lock down to a specific version, branch or commit, read up on "lock" files.

[notice] After you add or remove modules, make sure you rebuild the database, class and configuration manifests by going to http://yoursite.com/dev/build?flush=1 [/notice]

Creating a Module

Creating a module is a good way to re-use code and templates across multiple projects, or share your code with the community. SilverStripe already has certain modules included, for example the cms module and core functionality such as commenting and spam protection are also abstracted into modules allowing developers the freedom to choose what they want.

The easiest way to get started is our Module Skeleton. In case you want to share your creation with the community, read more about publishing a module.

Module Standard

The SilverStripe module standard defines a set of conventions that high-quality SilverStripe modules should follow. It’s a bit like PSR for SilverStripe CMS. Suggested improvements can be raised as pull requests. This standard is also part of the more highlevel Supported Modules Definition which the SilverStripe project applies to the modules it creates and maintains directly.

Coding Guidelines

• Declaration of level of support is provided for each module (either via README.md or composer) including the following:
  • Level of support provided.
  • Supporting user(s) and/or organisation(s).
• Complies to a well defined module directory structure and coding standards:
  • templates/ (for .ss templates)
  • src/ (for .php files)
  • tests/ (for *Test.php test files), and;
  • _config/ (for .yml config files)
• The module is a Composer package.
• All Composer dependencies are bound to a single major release (e.g. ^4.0 not >=4 or *).
• There is a level of test coverage.
• A clear public API documented in the docblock tags.
• Code follows PSR-1 and PSR-2 style guidelines.
• .gitattributes will be used to exclude non-essential files from the distribution. At a minimum tests, docs, and IDE/dev-tool config should be excluded.
• Add a PSR-4 compatible autoload reference for your module.

Documentation Guidelines

Documentation will use the following format:

• README.md provides:
  • Links or badges to CI and code quality tools.
  • A short summary of the module, end-user.
  • Installation instructions.
  • Testing/development instructions and a link to contributing instructions.
  • How to report security vulnerabilities. Note that PSR-9 / PSR-10 may be recommended once released.
  • Security, license, links to more detailed docs.
• CONTRIBUTING.md explaining terms of contribution.
• A changelog: CHANGELOG.md (may link to other more detailed docs or GitHub releases if you want). You could use a changelog generator to help create this.
• Has a licence (LICENSE file) - for SilverStripe supported this needs to be BSD.
• Detailed documentation in /docs/en as a nested set of GitHub-compatible Markdown files.
• It is suggested to use a documentation page named userguide.md in docs/en/ that includes documentation of module features that have CMS user functionality (if applicable). For modules with large userguides, this should be in a directory named userguide with an index.md linking to any other userguide pages.
• Links and image references are relative, and are able to be followed in viewers such as GitHub.
• Markdown may include non-visible comments or meta-data.

Documentation will cover:

• Installation
• Configuration
• Usage guides for key features; screenshots are recommended.
• A committers guide, covering pull request merging and release guidelines.

Related

• Module Skeleton
• Publishing a module