I'm writting a custom Gradle Task. Assuming the following is valid:
class MyTask extends DefaultTask {
#TaskAction
def doAction() {
return "my task""
}
}
I'm might be missing something obvious, but how do I get the value back when calling the task?
Related
I'm working on building a Gradle plugin that contains a single task which will combine two input files (the filename of one is constructed from command-line input) into one output file. I have followed this DZone article to set up my task and plugin classes. When I run the task, I see the log statement containing the command-line input, but the the plugin code to configure the task gets a null value for the input. How can I fix this? Example code below.
class FooPlugin implements Plugin<Project> {
#Override
void apply(Project project) {
project.tasks.register("foo", FooTask) {
if (it.hasProperty("bar") {
it.baseFile.convention(project.layout.projectDirectory.file("my${bar}.txt")
}
}
}
}
#CompileSTatic
abstract class FooTask extends DefaultTask {
#Input
String bar
#InputFile
abstract RegularFileProperty getBarFile()
#Option(option = "bar", description = "Does bar-ish things")
void setBar(bar) {
println "Setting bar variable from command-line argument $bar"
this.bar = bar
}
#TaskAction
void doFoo() {
// task logic using the bar variable
}
}
How do I create a nested parameter structure in a custom gradle plugin?
For starters, I am using Gradle 7.2. I want to make an expressive DSL-like structure for my plugin configuration, with a nested element
fileDiff {
file1 = file('${testFile1.getName()}')
file2 = file('${testFile2.getName()}')
messages {
message1 = 'Hi there'
}
}
While learning how to write Gradle Plugins I have been following the gradle plugin implementation docs, and they are great at showing what to do with the extension but not the "plugin" class.
So I have modeled my extension, FileDiffExtension like so
abstract class FileDiffExtension {
abstract RegularFileProperty getFile1()
abstract RegularFileProperty getFile2()
#Nested
abstract Messages getMessages()
void messages(Action<? super Messages> action) {
action.execute(getMessages())
}
}
And the nested Messages class is modeled as such
abstract class Messages {
abstract Property<String> getMessage1()
}
I think I am good up to this point. Then I need to pull my extension into my plugin and this is where I believe I am running into issues. My Plugin class currently looks like
class FileDiffPlugin implements Plugin<Project> {
#Override
void apply(Project project) {
project.tasks.register('fileDiff', FileDiffTask) {
project.extensions.create('fileDiff', FileDiffExtension)
project.fileDiff.extensions.create("messages", FileDiffExtension.messages)
file1 = project.fileDiff.file1
file2 = project.fileDiff.file2
messages = project.fileDiff.getMessages
}
}
}
I am trying to create a messages extension off of the root level extension fileDiff. Or maybe I am not supposed to set the messages object in the task to the getMessages() abstract method. But I have tried every combination I can think of. The actual task is shown below, but I don't think the problem lies here.
abstract class FileDiffTask extends DefaultTask {
#InputFile
abstract RegularFileProperty getFile1()
#InputFile
abstract RegularFileProperty getFile2()
#Input
abstract Property<Messages> getMessages()
#OutputFile
abstract RegularFileProperty getResultFile()
FileDiffTask() {
resultFile.convention(project.layout.buildDirectory.file('diff-result.txt'))
}
#TaskAction
def diff() {
// Print out the message
println messages.get().message1.toString()
// Now we do some fun file stuff
String diffResult
if (size(file1) == size(file2)) {
diffResult = "Files have the same size at ${file1.get().asFile.getBytes()} bytes}"
} else {
File largestFile = size(file1) > size(file2) ? file1.get().asFile : file2.get().asFile
diffResult = "${largestFile.toString()} is the largest file at ${largestFile.size()} bytes"
}
resultFile.get().asFile.write diffResult
println "File written to $resultFile"
println diffResult
}
private static long size(RegularFileProperty regularFileProperty) {
return regularFileProperty.get().asFile.size()
}
}
To test I am using the gradle test kit, and I'm currently getting the following error.
`
Could not create task ':fileDiff'.
No such property: messages for class: com.robschwartz.plugins.filediff.FileDiffExtension
Possible solutions: messages
`
Hm, according to docs you do not need to do anything with the sub-extension if it's marked as #Nested, it should just work. Have you tried to remove this line entirely?
project.fileDiff.extensions.create("messages", FileDiffExtension.messages)
This custom plugin exists in gradle's buildSrc/:
abstract class MyTask : DefaultTask() {
#get:Input
abstract val buildDir: Property<String>
#TaskAction
fun someTask() {
// do stuff
}
}
class DevelopmentPlugin : Plugin<Project> {
override fun apply(project: Project) {
project.tasks.run {
register("myTask", MyTask::class.java) {
inputs.property("buildDir", project.buildDir)
println(inputs.getProperties())
}
}
}
}
and by running the task with e.g. $ ./gradlew myTask fails with:
Could not determine the dependencies of task ':myTask'.
> Cannot query the value of task ':myTask' property 'rootDir' because it has no value available.
Also the prinln outputs {buildDir=null} meaning that the inputs.property("buildDir", project.buildDir) has failed.
How to pass the project.buildDir value from the Plugin in the task?
Using project.buildDir directly from inside the task is not an acceptable answer due to Gradle's incubating build-cache functionality.
Firstly, there is a class type issue which is not visible in Gradle.
buildDir is of type File while the property is String.
So "${project.buildDir}" should be used.
Secondly, since the property is abstract val it can directly be accessed in the closure. Therefore it can be set with:
// instead of:
inputs.property("buildDir", "${project.buildDir}")
// just this:
buildDir.set("${project.buildDir}")
I've written simple custom Gradle task that extends DefaultTask and does some action and I would like to pass it some parameter(s) using command line. At the bottom is code for adding task to list of available tasks and "implementation" of the task.
Now, when I execute: ./gradlew customTask -PcustomParam="value" how can I retrieve customParam value in doAction method?
project.tasks.create("customTask", CustomTask::class.java
open class CustomTask : DefaultTask() {
#TaskAction
fun doAction() {
// retrieve passed parameter
}
}
if (project.hasProperty('customParam')) {
println project.property('customParam')
}
#see project.property(String name)
I'm working on a Gradle plugin that has a Custom Task with two member variables that I would like to initialize using an extension class. I am extending the plugin class as follows:
class CustomPlugin implements Plugin<Project> {
#Override void apply(Project project) {
def extension = project.extensions.create("Custom", CustomExtension)
project.task("doTask", type: CustomTask, {
group = "Awesome"
description = "Runs a custom routine"
filePath = extension.filePath
name = extension.name
})
}
}
Is this the proper way to initialize a Task that extends DefaultTask? I'm trying to understand if initialization is done in CustomPlugin or if within the CustomTask one would use:
#TaskAction void removeUnusedResources() {
String filePath = project.Custom.lintXmlFilePath
String name = project.Custom.ignoreResFiles
// Proceed with the task action
}
Only the second approach seems to work for me. One common pattern I am noticing in other plugins is that tasks tend to be defined within the plugin using project.task("taskName") << { // task actions here} instead of creating a separate class that extends DefaultTask. What is the right convention and where can I find more information?