**IntelliJ Platform Plugin Template** is a repository that provides a pure boilerplate template to make it easier to create a new plugin project (check the [Creating a repository from a template][gh:template] article).
The main goal of this template is to speed up the setup phase of plugin development for both new and experienced developers by preconfiguring the project scaffold and CI, linking to the proper documentation pages, and keeping everything organized.
Before we dive into plugin development and everything related to it, it's worth mentioning the benefits of using GitHub Templates. By creating a new project using the current template, you start with no history and no reference to this repository. This allows you to create a new repository easily without having to copy and paste previous content, clone repositories, or clear the history manually.
After using the template to create your blank project, the [Template Cleanup][file:template_cleanup.yml] workflow will be triggered to override or remove any template-specific configurations, such as the plugin name, current changelog, etc. Once this is complete, the project is ready to be cloned to your local environment and opened with [IntelliJ IDEA][jb:download-ij].
For the last step, you have to manually review the configuration variables described in the [gradle.properties][file:gradle.properties] file and *optionally* move sources from the *com.github.username.repository* package to the one that works best for you. Then you can get to work implementing your ideas.
The recommended method for plugin development involves using the [Gradle][gradle] setup with the [gradle-intellij-plugin][gh:gradle-intellij-plugin] installed. The gradle-intellij-plugin makes it possible to run the IDE with your plugin and publish your plugin to the Marketplace Repository.
A project built using the IntelliJ Platform Plugin Template includes a Gradle configuration that's already been set up. Feel free to read through the [Using Gradle][docs:using-gradle] articles to better understand your build and learn how to customize it.
- Integration with the [gradle-changelog-plugin][gh:gradle-changelog-plugin], which automatically patches the change notes and description based on the `CHANGELOG.md` and `README.md` files.
The properties listed define the plugin itself or configure the [gradle-intellij-plugin][gh:gradle-intellij-plugin] – check its documentation for more details.
Since Kotlin 1.4, a dependency on a standard library (`stdlib`) is added automatically.
In most cases, it is not necessary to distribute this library with a plugin.
The [gradle.properties][file:gradle.properties] file explicitly alters the default behaviour of the Kotlin Gradle plugin by specifying this opt-out property:
In addition to the configuration files, the most crucial part is the `src` directory, which contains our implementation and the manifest for our plugin – [plugin.xml][file:plugin.xml].
The plugin configuration file is a [plugin.xml][file:plugin.xml] file located in the `src/main/resources/META-INF` directory. It provides general information about the plugin, its dependencies, extensions, and listeners.
The prepared template provides as little code as possible because it is impossible for a general scaffold to fulfill all the specific requirements for all types of plugins (language support, build tools, VCS related tools). The template contains only the following files:
These files are located in `src/main/kotlin`. This location indicates the language being used. So if you decide to use Java instead, sources should be located in the `src/main/java` directory.
To start with the actual implementation, you may check our [IntelliJ Platform SDK DevGuide][docs], which contains an introduction to the essential areas of the plugin development together with dedicated tutorials.
For those, who value example codes the most, there are also available [IntelliJ SDK Code Samples][gh:code-samples] and [IntelliJ Platform Explorer][jb:ipe] – a search tool for browsing Extension Points inside existing implementations of open-source IntelliJ Platform plugins.
Within the default project structure, there is a `.run` directory provided containing three predefined *Run/Debug configurations* that expose corresponding Gradle tasks:
| RunVerifications | Runs [`:runPluginVerifier`][gh:gradle-intellij-plugin-verifier-dsl] Gradle IntelliJ Plugin task to check the plugin compatibility against the specified IntelliJ IDEs. |
Continuous integration depends on [GitHub Actions][gh:actions], a set of workflows that make it possible to automate your testing and release process. Thanks to such automation, you can delegate the testing and verification phases to the CI and instead focus on development (and writing more tests).
The changelog is a curated list that contains information about any new features, fixes, and deprecations. When they are provided, these lists are available in a few different places: the [CHANGELOG.md](./CHANGELOG.md) file, the [Releases page][gh:releases], the *What's new* section of the Marketplace Plugin page, and inside of the Plugin Manager's item details.
There are many methods for handling the project's changelog. The one used in the current template project is the [Keep a Changelog][keep-a-changelog] approach.
The release process depends on the workflows already described above. When your main branch receives a new pull request or a regular push, the [Build](.github/workflows/build.yml) workflow runs multiple tests on your plugin and prepares a draft release.
The draft release is a working copy of a release, which you can review before publishing. It includes a predefined title and git tag, which is the current version of the plugin, for example, `v0.0.1`. The changelog is provided automatically using the [gradle-changelog-plugin][gh:gradle-changelog-plugin]. An artifact file is also built with the plugin attached. Every new Build overrides the previous draft to keep your *Releases* page clean.
When you edit the draft and use the <kbd>Publish release</kbd> button, GitHub will tag your repository with the given version and add a new entry to the Releases tab. Next, it will notify users that are *watching* the repository, and it will trigger the final [Release](.github/workflows/release.yml) workflow.
Releasing a plugin to the Marketplace is a straightforward operation that uses the `publishPlugin` Gradle task provided by the [gradle-intellij-plugin][gh:gradle-intellij-plugin]. The [Release](.github/workflows/release.yml) workflow automates this process by running the task when a new release appears in the GitHub Releases section.
The authorization process relies on the `PUBLISH_TOKEN` secret environment variable, which has to be acquired through the Secrets section of the repository Settings.
