Table 25.1. Scala plugin - tasks
Task name	Depends on	Type	Description
compileScala	compileJava	ScalaCompile	Compiles production
			Scala source files using
			scalac.
compileTestScala	compileTestJava	ScalaCompile	Compiles test Scala
			source files using scalac.

compileSourceSetScalacompileSourceSetJaScalaCompileva

scaladoc

-

ScalaDoc

Compiles the given source set's Scala source files using scalac.

Generates API documentation for the production Scala source files using scaladoc.

The Scala plugin adds the following dependencies to tasks added by the Java plugin.

Table 25.2. Scala plugin - additional task dependencies

Task name

Depends on

classes compileScala

testClasses compileTestScala

sourceSetClasses compileSourceSetScala

Figure 25.1. Scala plugin - tasks

25.3. Project layout

The Scala plugin assumes the project layout shown below. All the Scala source directories can contain Scala and Java code. The Java source directories may only contain Java source code. None of these directories need exist or have anything in them. The Scala plugin will compile whatever it finds, and handles anything which is missing.

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Table 25.3. Scala plugin - project layout

Directory	Meaning
src/main/java	Production Java source
src/main/resources	Production resources
src/main/scala	Production Scala source. May also contain Java source for joint
	compilation.
src/test/java	Test Java source
src/test/resources	Test resources
src/test/scala	Test Scala source. May also contain Java source for joint
	compilation.

src/sourceSet/java Java source for the given source set src/sourceSet/resourcesResources for the given source set

src/sourceSet/scala Scala source for the given source set. May also contain Java source for joint compilation.

25.3.1. Changing the project layout

TBD

Example 25.2. Custom Scala source layout

build.gradle

sourceSets { main {

scala {

srcDir 'src/scala'

}

}

}

25.4. Dependency Management

The Scala plugin adds a scalaTools configuration, which it uses to locate the Scala tools, such as scalac, to use. You must specify the version of Scala to use. Below is an example.

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Example 25.3. Declaring the Scala version to use

build.gradle

repositories { mavenCentral()

}

dependencies {

//Libraries needed to run the scala tools scalaTools 'org.scala-lang:scala-compiler:2.8.1' scalaTools 'org.scala-lang:scala-library:2.8.1'

//Libraries needed for scala api

compile 'org.scala-lang:scala-library:2.8.1'

}

25.5. Convention Properties

The Scala plugin does not add any convention properties to the project.

25.6. Source set properties

The Scala plugin adds the following convention properties to each source set in the project. You can use these properties in your build script as though they were properties of the source set object (see Section 21.3, “Conventions”).

Table 25.4. Scala plugin - source set properties

Property name

Type

scala SourceDirectorySet

(read-only)

scala.srcDirs Set<File>. Can set

using anything described in Section 18.5, “Specifying a set of input files”.

allScala

FileTree (read-only)

Default	Description
value
Not null	The Scala source files of this
	source set. Contains all .scal
	and .java files found in the
	Scala source directories,
	and excludes all other types
	of files.

[projectDir/src/The sourcename/scala]directories containing the Scala source files of this source set. May also contain Java source files for joint compilation.

Not null	All Scala source files of this
	source set. Contains only
	the .scala files found in
	the Scala source directories.

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These convention properties are provided by a convention object of type ScalaSourceSet.

The Scala plugin also modifies some source set properties:

Table 25.5. Scala plugin - source set properties

Property name	Change
allJava	Adds all .java files found in the Scala source directories.
allSource	Adds all source files found in the Scala source directories.

25.7. Fast Scala Compiler

The Scala plugin includes support for fsc, the Fast Scala Compiler. fsc runs in a separate daemon process and can speed up compilation significantly.

Example 25.4. Enabling the Fast Scala Compiler

build.gradle

compileScala { scalaCompileOptions.useCompileDaemon = true

// optionally specify host and port of the daemon: scalaCompileOptions.daemonServer = "localhost:4243"

}

Note that fsc expects to be restarted whenever the contents of its compile class path change. (It does detect changes to the compile class path itself.) This makes it less suitable for multi-project builds.

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