Gradle Variables and Properties: Difference between revisions
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* [[Gradle_Concepts#Properties|Gradle Concepts]] | * [[Gradle_Concepts#Properties|Gradle Concepts]] | ||
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gradle properties | |||
=Overview= | =Overview= | ||
Revision as of 01:29, 20 May 2018
Internal
There are two kinds of variables that can be declared in a build script: local variables and extra properties.
Local Variables
Local variables, which are a feature of the underlying Groovy language, are declared with the "def" keyword. They are only visible in the scope where they have been declared.
def myVariable = "something"
...
println myVariable
Extra Properties
Extra properties can be declared as follows:
...
ext {
log4jVersion = "2.1.7"
emailNotification = "build@example.com"
}
...
Internal
TODO: experiment with
gradle properties
Overview
The properties can be displayed with:
gradle properties
The command displays project properties, and the properties added by various plugins.
Auto-Delegation
Properties not defined in the build script are auto-delegating to the Project instance. For example:
name
and
project.name
are equivalent. Normally, using "name" is sufficient. In case you define a property or a method which has the same name as a member of the Project object, you will need to use the project property.
Predefined Properties
Project Coordinates
name
A String containing the name of the project directory. It automatically becomes the project's name coordinate. See Gradle Project Coordinates.
group
See Gradle Project Coordinates.
version
See Gradle Project Coordinates.
parent
Other Properties
project
The Project instance.
projectDir
The File instance corresponding to the directory containing the build script.
path
A String containing the absolute path of the project. The path of the root project is ":"
description
A String containing the description for the project.
displayName
buildDir
A File representing <projectDir>/build.
buildFile
rootDir
rootProject
rootProject.name
state
status
Plugin Properties
Plugins add specific properties. For a list of properties added by various plugins, consult the plugin pages.
Extra Properties
All objects in Gradle's domain model can hold extra user-defined properties. They can be declared in build.gradle, using a special syntax. Once the properties have been added, they can be read and set like predefined properties.Extra properties can be accessed from anywhere their owning object can be accessed, giving them a wider scope than local variables. Extra properties on a project are visible from its subprojects.
By requiring special syntax for adding a property, Gradle can fail fast when an attempt is made to set a predefined or extra property but the property is misspelled or does not exist.