= Advanced Tasks

[[incremental_tasks]]
== Incremental tasks

In Gradle, implementing a task that skips execution when its inputs and outputs are already `UP-TO-DATE` is simple and efficient, thanks to the <<incremental_build.adoc#incremental_build,Incremental Build>> feature.

However, there are times when only a few input files have changed since the last execution, and it is best to avoid reprocessing all the unchanged inputs.

[[sec:antlr_source_set_properties]]
== Source set properties

The ANTLR plugin adds the following properties to each source set in the project.

`antlr.srcDirs` — `Set<File>`::
The source directories containing the ANTLR grammar files of this source set.
Can set using anything <<working_with_files.adoc#sec:specifying_multiple_files, that implicitly converts to a file collection>>.

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The plugin adds a number of tasks to the project that perform the quality checks. You can execute the checks by running `gradle check`.

Note that Checkstyle will run with the same Java version used to run Gradle.

[[sec:checkstyle_tasks]]
== Tasks

The Checkstyle plugin adds the following tasks to the project:

Laura Kassovic <******@****.***> 1701107622 -0800

<5> Gradle build scripts of the two subprojects - `subproject-a` and `subproject-b`
<6> Source code and/or additional files for the projects

== Invoking Gradle

=== IDE

Gradle is <<gradle_ides.adoc#gradle_ides,built-in to many IDEs>> including Android Studio, IntelliJ IDEA, Visual Studio Code, Eclipse, and NetBeans.

Gradle can be automatically invoked when you build, clean, or run your app in the IDE.

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$ gradlew.bat build

include::{snippetsPath}/wrapper/simple/tests/wrapperBatchFileExecution.out[]
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Consult the <<gradle_wrapper.adoc#gradle_wrapper_reference,Gradle Wrapper reference>> to learn more.

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Build scripts can optionally define task dependencies.
Gradle then automatically determines the task execution order.

Consult the <<more_about_tasks.adoc#more_about_tasks,Task development chapter>> to learn more.

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Federico La Penna <******@****.***> 1705182549 +0100

These properties can be set directly in the build script.
For example, setting the HTTP proxy host would be done with `System.setProperty('http.proxyHost', 'www.somehost.org')`.

Alternatively, the properties can be <<build_environment.adoc#sec:gradle_configuration_properties,specified in `gradle.properties`>>.

*Example 1:* Configuring an HTTP proxy using `gradle.properties`:
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systemProp.http.proxyHost=www.somehost.org
systemProp.http.proxyPort=8080

== Project properties

Project properties are available on the link:{groovyDslPath}/org.gradle.api.Project.html[Project] object.
They can be set from the command line using the `-P` / `--project-prop` <<command_line_interface.adoc#sec:environment_options, environment option>>.

The following examples demonstrate how to set project properties in different ways.

*Example 1:* Setting a project property via the *command line*:
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