I have a gradle task for copying, like below:
task hello << {
println "hello"
}
task myCopy(type: Copy) {
println "copy"
from(file('srcDir'))
into(buildDir)
}
but "myCopy" task gets executed even when I execute "hello" like below:
gradle hello
Now I understand this is the intended behavior. I read thru the entire Gradle Task page here: https://docs.gradle.org/current/userguide/more_about_tasks.html . But I want to make "myCopy" task only execute when explicitly executed. In other words, I want to make it so that "myCopy" does not execute when I execute "hello", and only execute when I run the command:
gradle myCopy
Is there a way to do this? Thanks
It's not getting executed, but getting configured. Take a closer look, nothing get copied if you don't run your copy task. Configuration is happenning always and for all the tasks you have, in your case you are printing "copy" during the configuration. Move it into the doLast section to print it at the execution phase, as:
task myCopy(type: Copy) {
doLast {
println 'Copy'
}
from(file('srcDir'))
into(buildDir)
}
Note, that doLast closure is the same as a task closure with << sign and it is executed only if task executed at the execution phase.
Related
I have a task which copies reports:
task copyReports(type: Copy) {
dependsOn = ['cleanTest', 'test -i']
from 'build/reports/tests/test/classes'
into 'reports'
println 'FINISHED COPYING FILES'
}
This task depends on cleanTest and test. I want to run test task with the parameter -i to see output of the tests. How to pass this parameter into dependsOn method? At the moment I get the next error:
Task with path 'test -i' not found in root project
I also tried without single quotes. Like this:
dependsOn = [cleanTest, test -i]
Then I get the next error:
Could not get unknown property 'i' for task ':copyReports' of type org.gradle.api.tasks.Copy.
Any ideas?
The
build.gradle
task hello (type: Copy) {
doLast {
println "print from within"
}
println "print from outside"
}
when run
gradle -q hello
the doLast{} closure is not even touched. change doLast to doFirst, I get the same result:
D:\>gradle -q hello
print from outside
without the doLast or doFirst:
task hello (type: Copy) {
//doLast{
println "print from within"
//}
println "print from outside"
}
it works fine:
D:\>gradle -q hello
print from within
print from outside
This seems happening only with tasks of type Copy. can you please help clarifying? I am using gradle 2.4.
I thought it would be helpful for the people who come to this place on the same question. Though the above explanation is conceptually making sense. There is no proper solution mentioned in the answer. Here is the solution on how i achieved Copy task with doLast execution.
task hello () {
doLast{
copy {
println "print from within"
}
}
println "print from outside"
}
This would provide the execution of copy task along with doLast.
$ gradle -q hello
print from outside
print from within
Hope this is useful.
If you run the task without -q switch you'll notice that the task is already marked as UP-TO-DATE - which means that no actions (and you add an action via doLast) were executed.
Why is that? In this particular example, you have configured no inputs and outputs for the task. Copy tasks resolve it's being up-to-date base on the inputs and outputs and since none were configured Gradle assumes there's no need for it to be run.
It was my understanding that printlns get displayed during a task's configuration phase (unless they are for example placed within a doLast action). Therefore given the following task:
ext {
changeset = 'placeholderChangeset'
}
task getChangeset {
process = '/usr/bin/git describe --always'.execute()
process.waitFor()
changeset = process.getText()
println "Changeset obtained from GIT is: $changeset"
doLast {
println '\n++++++++++++++++++++++++++++++++++'
println '+++++ task getChangeset executed'
println '++++++++++++++++++++++++++++++++++++'
}
}
If I run this using ./gradlew then the output will be:
********************************
** task getChangeset
********************************
Changeset obtained from GIT is: 9bd49ca
If it run it using ./gradlew getChangeset then the output will be:
********************************
** task getChangeset
********************************
Changeset obtained from GIT is: 9bd49ca
...
:app:getChangeset
++++++++++++++++++++++++++++++++++
+++++ task getChangeset executed
++++++++++++++++++++++++++++++++++++
In the first run, the task has not been executed. Yet the value of the changeset is displayed, and therefore the process = ... execute() line has been executed.
Therefore I'm confused, what does it actually mean for a task to be "executed", if in this example, it obviously doesn't mean the code statements within the task haven't executed, as they most clearly have in order to get the value of the changeset.
What's the difference between a task not executing and a task executing if its not having an effect on the execution or non execution of the code within the task?
A println isn't somehow special or different from other code. Any code that is not inside the doLast{} block will be executed in the configuration phase, and the dolast{} block will be executed in the execution phase.
In my build.gradle script, I have a lot of tasks, each depending on zero or more other tasks.
There are three 'main' tasks which can be called: moduleInstallation, backupFiles and restoreFiles.
Here's the question: I would like to be able to tell Gradle which tasks to execute and which don't need to execute. For example, when calling moduleInstallation, I want all depending tasks to execute (regardless of their UP-TO-DATE flag), but not the restore tasks. I've tried altering the phase in which the tasks get executed (e.g. config phase, execution phase,...) and a couple of other things, but all tasks just keep getting executed.
A solution I've thought of was just stating in the main tasks that, when this main task is called (f.e. moduleInstallation), we set the UP-TO-DATE flag of all non-related tasks to false, so they don't get executed. Is that possible?
EDIT: Here's an example:
When moduleInstallation is called (which depends on backupFiles), restoreFiles (which depends on restoreFromDate) is executed too.
First main action
task moduleInstallation << {
println "Hello from moduleInstallation"
}
task backupFiles {
doLast {
println "Hello from backupFiles"
}
}
Second main action
task restoreFiles {
println "Hello from restoreFiles"
}
task restoreFromDate {
println "Hello from restoreFromDate"
}
Dependencies:
moduleInstallation.dependsOn backupFiles
restoreFiles.dependsOn restoreFromDate
So when I type gradle moduleInstallation in the terminal, I get the following output:
Hello from restoreFromDate
Hello from restoreFiles
Hello from backupFiles
Hello from moduleInstallation
The second snippet has to use doLast (or its << shortcut) like the first snippet. Otherwise, the code is configuration code and will always be evaluated, no matter which tasks are eventually going to be executed. In other words, it's not the restoreFiles and restoreFromDate tasks that are being executed here (as one can tell from the bits of command line output that you don't show), but (only) their configuration code.
To better understand what's going on here (which is crucial for understanding Gradle), I recommend to study the Build Lifecycle chapter in the Gradle User Guide.
A)
task build << {
description = "Build task."
ant.echo('build')
}
B)
task build {
description = "Build task."
ant.echo('build')
}
I notice that with type B, the code within the task seems to be executed when typing gradle -t - ant echoes out 'build' even when just listing all the various available tasks. The description is also actually displayed with type B. However, with type A no code is executed when listing out the available tasks, and the description is not displayed when executing gradle -t. The docs don't seem to go into the difference between these two syntaxes (that I've found), only that you can define a task either way.
The first syntax defines a task, and provides some code to be executed when the task executes. The second syntax defines a task, and provides some code to be executed straight away to configure the task. For example:
task build << { println 'this executes when build task is executed' }
task build { println 'this executes when the build script is executed' }
In fact, the first syntax is equivalent to:
task build { doLast { println 'this executes when build task is executed' } }
So, in your example above, for syntax A the description does not show up in gradle -t because the code which sets the description is not executed until the task executed, which does not happen when you run gradle -t.
For syntax B the code that does the ant.echo() is run for every invocation of gradle, including gradle -t
To provide both an action to execute and a description for the task you can do either of:
task build(description: 'some description') << { some code }
task build { description = 'some description'; doLast { some code } }