Gradle: How to init SourceTask's property ‘source’ with extension property? - gradle

Question

My plugin registers an extension and some custom task that inherited from org.gradle.api.tasks.SourceTask.
class MyPlugin implements Plugin<Project> {
private final Instantiator instantiator
private final FileResolver fileResolver
#Inject
MyPlugin (Instantiator instantiator, FileResolver fileResolver) {
this.instantiator = instantiator
this.fileResolver = fileResolver
}
void apply(Project project) {
MyPluginExtension extension = project.extensions.create("myPlugin", MyPluginExtension, project, instantiator, fileResolver)
project.tasks.create('doSomething', MyCustomTask) {}
}
}
class MyPluginExtension {
final MySourceSetContainer source
MyPluginExtension(Project project, Instantiator instantiator, FileResolver fileResolver) {
source = instantiator.newInstance(ImplMySourceSetContainer, project, instantiator, fileResolver)
}
void source(Closure closure) {
ConfigureUtil.configure(closure, source)
}
}
class MyCustomTask extends SourceTask {
#TaskAction
void act() {
// something
}
}
And now, if I configure build script:
myPlugin {
source{
main {
something {
srcDirs "src/main/resources"
}
}
}
}
doSomething {
source = myPlugin.source.main.something.asFileTree
}
- All works fine. But I want to initialize task property source by value from MyPluginExtension.
source = extension.source.findAll().inject(project.files().asFileTree, { result, item -> result + item.html.asFileTree })
I can't extract extension property at the execution phase as it described in the userguide (https://docs.gradle.org/4.2.1/userguide/custom_plugins.html#sec:mapping_extension_properties_to_task_properties), because getter for source that declared in superclass org.gradle.api.tasks.SourceTask marked with annotation #org.gradle.api.tasks.SkipWhenEmpty and task will be skipped.
How can I initialize task's property with value from extension before execution phase?
Thx.

Answer 1

I'm not sure that I fully understand what you are doing but you could likely use a closure to delay evaluation. See Project.files(Object...)
Eg:
doSomething {
def myClosure = {
extension.source.findAll().inject(project.files().asFileTree, { result, item -> result + item.html.asFileTree })
}
source = files(myClosure)
}

Answer 2

Resolved by wrapping source init in closure:
class MyPlugin implements Plugin<Project> {
// ...
void apply(Project project) {
MyPluginExtension extension = project.extensions.create("myPlugin", MyPluginExtension, project, instantiator, fileResolver)
project.tasks.create('doSomething', MyCustomTask) { task ->
task.source = {
extension.source.findAll().inject(new HashSet<File>(), { result, item -> result + item.html.srcDirs })
}
}
}
}