Say, you have following task:
task commandA() {
doLast {
project.ext.ping = 'PING'
}
}
This will work:
task commandB() {
dependsOn commandA
doLast {
println ping
}
}
This will fail:
task commandC(type: Exec) {
dependsOn commandA
commandLine "echo", ping
}
With Could not find property 'ping' on task 'commandC'. error message.
So, how one can declare dependency for an exec-type task and set some variable in that dependency?
Just don't initialize the variable within the doLast block, since it's getting initialized at the execution phase, but commandLine "echo", ping is trying to get it at the configuration phase of the build.
So, you need something like that:
task commandA() {
project.ext.ping = 'PING'
}
Or even without task, as follows:
project.ext.ping = 'PING'
Because configuration of any task is always executed, even if the task's action won't be executed.
Another solution is to use exec-action, not exec-task, something like this:
task commandA() {
doLast {
project.ext.ping = 'PING'
}
}
task commandC {
dependsOn commandA
doLast {
exec {
commandLine ping, "192.168.100.1"
}
}
}
In this case, exec-closure will be done during execution phase wuth the ping variable already available.
You can read about build lifecycle in the official Gradle user guide
Related
I try to investigate a Gradle and follows some tutorials, but I have confused with the following:
I created are a couple of simple tasks:
task startProcess{
println 'startProcess'
}
task doStep2{
println 'Step2'
}
task doStep3{
println 'Step3'
}
task finishProcess{
println 'finishProcesss'
}
And try to execute one of them:
gradle finishProcess
Or with defaultTasks with command gradle build:
defaultTasks `finishProcess`
task startProcess{
println 'startProcess'
}
task doStep2{
println 'Step2'
}
task doStep3{
println 'Step3'
}
task finishProcess{
println 'finishProcesss'
}
In both options, I got the same result:
> Configure project :
startProcess
Step2
Step3
finishProcesss
BUILD SUCCESSFUL in 1s
How to execute exactly one of them?
You have to use register, I think if you did not use it, You're only asking Gradle to execute these tasks.
for example
tasks.register('startProcess') {
doLast {
println 'startProcess'
}
}
tasks.register('doStep2') {
doLast {
println 'Step2'
}
}
tasks.register('doStep3') {
doLast {
println 'Step3'
}
}
tasks.register('finishProcess') {
doLast {
println 'finishProcesss'
}
}
tasks.named("build") { finalizedBy("finishProcess") }
Registering these tasks, you will be able to call each one indivadually.
If you want to link a specific task, with a build task for example.
Then you can use finalizedBy like the following.
tasks.named("build") { finalizedBy("finishProcess") }
This will call the finishProcess task, whenever build is triggered.
I strongly recommend the official gradle documintation for more information about tasks.
I am working with a build.gradle file that has multiple ways to specify executions for a task - setup. To call a task from another gradle file - runtests.gradle, I created a task - testTask and added task dependency using dependsOn, but this implementation does not seem to work and giving out an error like :
Could not find property 'testTask' on root project 'GradleFile
My build file looks like this :
build.gradle
task setup(dependsOn: testTask) <<
{
println "In main execution"
}
// new task
task testTask(type: GradleBuild) {
if (getEnvironmentVariable('RUN_TEST').equalsIgnoreCase("true")) {
buildFile = "../Behave/runtests.gradle"
tasks = ['mainTask']
}
else {
println "Exiting runTests Task"
}
}
setup.doFirst {
println "In first execution"
}
setup.doLast {
println "In last execution"
}
D:\>gradle -q GradleFile/build.gradle setup
I am not looking to make much changes to existing tasks, so is there any other workaround I should try?
I have been through many links but could not find anything that suits this scenario. Looking for suggestions please.
Gradle is sensitive to the ordering of tasks in the build script if a task instance is given in the dependsOn. The task setup depends on task (instance) testTask which, at the moment the build script is compiled, doesn't exist yet. The most common options to solve the issue are:
Define task setup below testTask:
task testTask(type: GradleBuild) {
}
task setup(dependsOn: testTask) {
}
Use a relative path to the task, i.e. the task's name, in the dependsOn
task setup(dependsOn: 'testTask') {
}
task testTask(type: GradleBuild) {
}
Please find more details in Javadoc of Task.
I need to create an initialize task that will run before all other task when I execute it.
task A {
println "Task A"
}
task initializer {
println "initialized"
}
If I execute gradle -q A, the output will be:
>initialized
>Task A
Now if i'll add:
task B {
println "Task B"
}
Execute gradle -q B, and I get:
>initialized
>Task B
So it doesn't matter which task I execute, it always get "initialized" first.
You can make every Task who's name is NOT 'initializer' depend on the 'initializer' task. Eg:
task initializer {
doLast { println "initializer" }
}
task task1() {
doLast { println "task1" }
}
// make every other task depend on 'initializer'
// matching() and all() are "live" so any tasks declared after this line will also depend on 'initializer'
tasks.matching { it.name != 'initializer' }.all { Task task ->
task.dependsOn initializer
}
task task2() {
doLast { println "task2" }
}
Or you could add a BuildListener (or use one of the convenience methods eg: Gradle.buildStarted(...))
Seems like you aim execution phase, and you want a task precursing each task or just run as a first task in the execution phase?
If you want a task to always execute in every project before each other task after its being evaluated you can add a closure to he main build.gradle:
allprojects {
afterEvaluate {
for(def task in it.tasks)
if(task != rootProject.tasks.YourTask)
task.dependsOn rootProject.tasks.YourTask
}
}
or
tasks.matching {it != YourTask}.all {it.dependsOn YourTask}
You can also use the Task Execution Graph to define the lifecycle. There are few ways of achieving your goal, depending on your needs and a project structure.
The previously suggested solution with dependsOn works fine, but I don't like about it that it changes and clutters the task dependencies. The first solution coming to my mind is using Gradle Initialization Scripts. They are really cool. But, the usage is a bit tedious: currently there is no way to have a default project-local Gradle init script. You have to either explicitly specify the script(s) on command line, or place them in USER_HOME/GRADLE_HOME.
So another solution (already briefliy mentioned by #lance-java) which can be used to run some initialization, like a init task/script, is "build listeners". Depending on how early/late the initialization code should run, I use one of these two:
gradle.afterProject {
println '=== initialized in afterProject'
}
or
gradle.taskGraph.whenReady {
println '=== initialized in taskGraph.whenReady'
}
Here the docs of the Gradle interface and of BuildListener.
Note that some of the events occur very early, and you probably can't use them because of that, like e.g. beforeProject and buildStarted (explanations here and there).
I want execute some command from command line in gradle task(e.g. print all files in dir):
task dir(type: Exec) {
def adbCommand = ["dir", "*.*"]
commandLine adbCommand
standardOutput = new ByteArrayOutputStream()
doLast {
println ("result = " + standardOutput)
}
}
It's work. OK. But when I put it on onLast section it's not work:
task dir(type: Exec) {
doLast {
def adbCommand = ["dir", "*.*"]
commandLine adbCommand
standardOutput = new ByteArrayOutputStream()
println ("result = " + standardOutput)
}
}
I get error:
FAILURE: Build failed with an exception.
What went wrong:
Execution failed for task ':app:dir'.
execCommand == null!
The reason is in the fact, that task of Exec should be configured during configuration phase of the build, otherwise your task will be not configured and fail.
In you first example everything works due to configuration happens at the configuratyion phase. Your second example tries to configure the task within doLast closure - right after the task is executed yet.
If you really need to execute something in doLast, you can use something like this, without creating special task:
task someTaskName {
doLast {
exec {
commandLine adbCommand
}
}
}
Here is exec-specification used to execute some command and it's configured and executed at the same time.
I wanted to build a particular module from my project via a task, which will in turn run its tests. Basically I want to execute, "gradle :module:build" from a task.
task thatBuildsTheModule() << {
.....
}
task A() << {
......
tasks.thatBuidsTheModule.execute()
......
}
How can I do this ?
You're close. It's not recommended to call execute on a task. Instead use the task graph and make your builder task a dependant of your A task, labeled anotherTask in this example
// create builder task
task thatBuildsTheModule << {
println "Hello $it.name"
}
// create our other task
task anotherTask << {
println "Hello $it.name"
}
// make `anotherTask`'s execution depend on the execution of our builder task
anotherTask.dependsOn thatBuildsTheModule
Now we can see that executing just the anotherTask task we also execute the thatBuildsTheModule task
$ ./gradlew -q anotherTask
Hello thatBuildsTheModule
Hello anotherTask