:samples-dir: /home/tcagent1/agent/work/64493a816be20d5a/promote-projects/gradle/build/git-checkout/subprojects/docs/build/working/samples/install/composite-builds-basics
:gradle-version: 7.3.1

= Composite Builds Basics Sample

[.download]
- link:zips/sample_composite_builds_basics-groovy-dsl.zip[icon:download[] Groovy DSL]
- link:zips/sample_composite_builds_basics-kotlin-dsl.zip[icon:download[] Kotlin DSL]

NOTE: You can open this sample inside an IDE using the https://www.jetbrains.com/help/idea/gradle.html#gradle_import_project_start[IntelliJ native importer] or https://projects.eclipse.org/projects/tools.buildship[Eclipse Buildship].

== Defining and using a composite build

This sample shows how 2 Gradle builds that are normally developed separately and combined using binary integration can be wired together into a composite build with source integration. The `my-utils` multiproject build produces 2 different java libraries, and the `my-app` build produces an executable using functions from those libraries.

Note that the `my-app` build does not have direct dependencies on `my-utils`. Instead, it declares module dependencies on the libraries produced by `my-utils`:

====
include::sample[dir="groovy",files="my-app/app/build.gradle[tags=app_dependencies]"]
include::sample[dir="kotlin",files="my-app/app/build.gradle.kts[tags=app_dependencies]"]
====

== Using command-line composite build

When using a composite build, no shared repository is required for the builds, and no changes need to be made to the build scripts.

1. Change the sources of `Number.java`
2. Run the `my-app` application, including the `my-utils` build.

```
cd my-app
gradle --include-build ../my-utils run
```

Using _dependency substitution_, the module dependencies on the util libraries are replaced by project dependencies on `my-utils`.

== Converting `my-app` to a composite build

It's possible to make the above arrangement persistent, by making `my-app` a composite build that includes `my-utils`.

```
cd my-app
echo "includeBuild '../my-utils'" >> settings.gradle
gradle run
```

With this configuration, the module dependencies from `my-app` to `my-utils` will always be substituted with project dependencies.

While simple, this approach has the downside of modifying the `my-app` build.

== Using separate composite build

It is also possible to create a separate composite build that includes both the `my-app` and `my-utils` builds.

====
include::sample[dir="groovy",files="settings.gradle[]"]
include::sample[dir="kotlin",files="settings.gradle.kts[]"]
====

Note that it is not yet possible to execute tasks in an included build from the command line. Instead, the build user must create delegating tasks in the composite.

====
include::sample[dir="groovy",files="build.gradle[tags=run]"]
include::sample[dir="kotlin",files="build.gradle.kts[tags=run]"]
====

```
gradle run
```

We are working on a mechanism to permit tasks in included builds to be referred to directly on the command line. Stay tuned!




```shell
# Build the app
./gradlew :my-app:app:build 

# the built application
/my-app/app/build/distributions/app-1.0

# tree output
# ├── bin
# │   ├── app
# │   └── app.bat
# └── lib
#     ├── app-1.0.jar
#     ├── commons-lang3-3.4.jar
#     ├── number-utils-1.0.jar
#     └── string-utils-1.0.jar
```

references  
https://docs.gradle.org/current/samples/sample_composite_builds_basics.html  
https://docs.gradle.org/current/userguide/application_plugin.html