For Gradle users it is important to understand how Groovy deals with script variables. Groovy has two types of script variables. One with a local scope and one with a script wide scope.
Example B.1. Variables scope: local and script wide
scope.groovy
String localScope1 = 'localScope1'
def localScope2 = 'localScope2'
scriptScope = 'scriptScope'
println localScope1
println localScope2
println scriptScope
closure = {
println localScope1
println localScope2
println scriptScope
}
def method() {
try {localScope1} catch(MissingPropertyException e) {println 'localScope1NotAvailable' }
try {localScope2} catch(MissingPropertyException e) {println 'localScope2NotAvailable' }
println scriptScope
}
closure.call()
method()Output of gradle
> gradle localScope1 localScope2 scriptScope localScope1 localScope2 scriptScope localScope1NotAvailable localScope2NotAvailable scriptScope
Variables which are declared with a type modifier are visible within closures but not visible within methods. This is a heavily discussed behavior in the Groovy community. [26]
It is important to keep in mind that Gradle has a distinct configuration and execution phase (see Chapter 51, The Build Lifecycle).
Example B.2. Distinct configuration and execution phase
build.gradle
classesDir = file('build/classes')
classesDir.mkdirs()
task clean(type: Delete) {
delete 'build'
}
task compile(dependsOn: 'clean') << {
if (!classesDir.isDirectory()) {
println 'The class directory does not exist. I can not operate'
// do something
}
// do something
}Output of gradle -q compile
> gradle -q compile The class directory does not exist. I can not operate
As the creation of the directory happens during the configuration phase, the
clean
task removes the directory during the execution phase.
[26] One of those discussions can be found here: http://groovy.329449.n5.nabble.com/script-scoping-question-td355887.html