How to use variable outside the task in gradle script - gradle

I am stuck in a situation where need to read a file (for some values, let's say version number) from inside a war file and use it somewhere else in the same script (I am exploding the war file for this purpose using a Copy task). To explain the need, I will write down with the example below:
Defined the variable:
def projVersion = "NULL"
Exploding the war:
task explodedWar(type: Copy) {
from zipTree("$buildPath/projectName.war")
into file("$buildPath/projectName")
}
Reading the file from exploded folder and getting a value:
task warVersion(dependsOn : ['explodedWar']) <<{
Properties versionFile = new Properties()
versionFile.load(new FileInputStream("$buildPath/projectName/META-INF/MANIFEST.MF"))
ext.projVersion = versionFile.getProperty("Version")
}
When Using the variables new value outside the task (This part is throwing Error):
println "Variables new value: " + warVersion.projVersion
When Using the variables new value inside some other task (This part is Successful):
task VersionPrint(dependsOn : ['warVersion']) <<{
println "Project Version under print task" + warVersion.projVersion
}
Basically, I am able to use the new value of the variable inside any other task in the same script, but when I am trying to use the variables new value outside the task areas (sorry but it's a need), it is throwing error:
Error (When using variable outside the task) ***
* What went wrong:
A problem occurred evaluating root project 'Scripts'.
> Could not find property 'projVersion' on task ':warVersion'
Let me know, Am I trying to achieve something which is achievable? or is it going to be rule breaking way for gradle?
If it is possible what I am searching for, please let me know the solution, how to achieve.

You're not thinking about the build lifecycle correctly.
When you define the warVersion task, which depends on explodedWar, you're telling Gradle that you want to set the property projVersion during the execution of the warVersion task.
This means that you can't attempt to read the property until after the warVersion task is run. Otherwise, it will not be defined. If you attempt to "use the value outside of a task", you're no longer waiting for the warVersion task to run. Code that is outside of the scope of a task will be executed during the configuration phase, not the execution phase.
when I am trying to use the variables new value outside the task areas (sorry but it's a need), it is throwing error:
You need to refactor how you define the projVersion variable.
You could refactor your code so you don't need to use the value outside of tasks.
You could use the new PropertyState API for lazy-evaluated properties.
You could change your logic to execute during the configuration phase.
The last is not ideal as it bypasses task conveniences, such as up-to-date checking. However, you can try it out by changing your copy task to call Project#copy, then read the properties file and declare your properties value, all outside of the scope of tasks:
copy {
from zipTree("$buildPath/projectName.war")
into file("$buildPath/projectName")
}
Properties versionFile = new Properties()
versionFile.load(new FileInputStream("$buildPath/projectName/META-INF/MANIFEST.MF"))
ext.projVersion = versionFile.getProperty("Version")
This code will be executing during the configuration phase. Now, anywhere after this point you should be able to reference ext.projVersion.

Related

Gradle not running copy task after jar

I am trying to do something like this:
jar {
doLast{
from "build/libs/TheJar.jar"
into "."
}
}
So far, I have tried various tutorials including all forms from this answer but non have worked. The only thing that works is calling a separate task but I'd like to know why my construction is wrong and why can't I run something after the jar or shadowJar tasks.
It looks like you took some parts of the answers in the linked post and somehow mixed them without knowing what your final code actually does.
Tasks in Gradle may have a type (e.g. Copy, Jar, ...). This type defines what the task will do once it gets executed (so called task actions). A task without a type won't do anything when its executed, unless you add task actions manually. Using doFirst will add the passed action (also called closure) to the start of the list of task actions, using doLast will add it to the end of the list.
Everything outside of doFirst and doLast closures is not part of the execution of the task, but can be used to configure the task:
task example {
doLast {
println "second action"
}
doFirst {
println "first action"
}
println "configuration"
}
Run the code above with gradle example and you will see the order of the log messages as configuration, first action, second action.
Task configuration will run, even if the task won't be executed later on. Even if you call gradle (without any task names as arguments), the console will still print configuration. This was the actual problem in the linked question.
Lets come to the real question: How to copy a file?
Well, Gradle offers two ways to copy a file. The first one is the task type Copy. You can create a task based on this type, apply your configuration and then either call it directly from the command line or define task dependencies using dependsOn or finalizedBy:
task copySomeFiles(type: Copy) {
from '...'
into '...'
}
However, you don't want to create an additional task. Gradle also has a method called copy that may be called anywhere in your script and will instantly copy the files:
copy {
from '...'
into '...'
}
The code above will copy your files, but it will copy your files every time Gradle executes (which may be often, e.g. when using an IDE). To solve this problem, you may move your code with copy to a task action, e.g. inside a doFirst or doLast closure:
jar {
doLast {
copy {
from "build/libs/TheJar.jar"
into "."
}
}
}
As you can see, your code was missing the copy statement. Now, whenever your task jar gets executed, its last task action will copy the files as intended.
Bonus question: Why is there no error?
The "problem" in your case is that your code is perfectly valid Gradle code. The task jar is of type Jar. Every task of type Jar may be configured using methods called from and into. The method from adds files to the JAR file and the method into sets the destination directory inside the JAR. So instead of copying, your code configures the underlying task jar. However, this has no negative consequences, as this configuration gets applied inside doLast, which only runs once the JAR file has already been created. Something that already happened cannot be configured.

Build Gradle getProperties before running already made task

I’m trying to use a Java, Serenity-BDD project with gradle version 4.8+, but the application is not pulling the CLI arguments of -Denvironment and -Dservicebranches. I have these properties as blank values in my local.properties file, and they’re not getting assigned when my app runs.
./gradlew --build-cache build -Dwebdriver.remote.url=${SELENIUM_REMOTE_URL} -Denvironment=${ENVIRONMENT} -Dservicebranches=${SERVICE_BRANCHES} -Dtags=${TAGS}
I have a local.properties file with properties that are being successfully dependency injected into the project (through Serenity-Spring). I'm hoping that these CLI arguments will override these values:
servicebranches=
environment=local
But right now, anything specified in the CLI arguments are not being passed into the project. Either through DI, or through explicitly grabbing the environment variables in the build.gradle, which what I've tried hasn't been working.
Here's a few things which I have tried in the build.gradle:
//task integrationTests() {
// doFirst
// {
// def environment = System.getProperty('environment')
// def servicebranches = System.getProperty('servicebranches')
// }
// tasks.build.execute()
//}
//integrationTests.dependsOn(build)
//build.doFirst{
// systemProperties System.properties
// def environment = System.properties['environment']
// environment = environment //This actually flags with 'Silly assignment'
//}
build.doFirst{
def environment = System.getProperty('environment')
def servicebranches = System.getProperty('servicebranches')
}
The latest one seems to still be missing a step, because the program is still working, but the args are still not getting through. I've even tried -Denvironment=potato, and no errors have come up because I do not have a property or properties file named that.
I've also tried using the -P tag instead of -D tag, but that doesn't seem to be working either.
All I’m trying to do is use build.gradle to use System.getProperty(‘environment’) and System.getProperty(‘servicebranches’) before I use the already created ‘build’ task that comes with Serenity. How would I do this? Do I build a whole new task, where I use these getProperties, and then call the build task? Do I have to specify the assignment of these same named variables in the local.properties file?
-D is for system properties in Gradle. Try with -P instead (https://docs.gradle.org/current/userguide/build_environment.html#sec:project_properties)
I know this is a very old question but here's what I did to solve my problem, I got the idea from here: https://github.com/serenity-bdd/serenity-documentation/pull/120/files
Serenity was not pulling the environment from gradle to use EnvironmentSpecificProperties, it kept saying "undefined property for environment 'null" when I removed the default environment. I had to add this to my Gradle file:
test {
systemProperty 'environment', System.properties['environment']
}

Wiring two Gradle tasks together via a property

The question:
In Gradle, how do I make the output of one task be a property and the input of another task be that same property? Especially in the context of that property being needed at configuration time.
What I'm trying to accomplish:
I'm attempting to write a Tar task that depends on user input. I'm having trouble with the need for lazy configuration given that the "baseName" is not known at configuration time.
Code
Here's what I would like to work but it doesn't.
task saveDb(type: Tar, dependsOn: getTarBaseName) {
// Next line doesn't work but does if I surround 2nd param with '{}'
inputs.property("baseName", getTarBaseName.baseName) // Doesn't work
from file("$dbsDir/data")
destinationDir = file(project.dbsBackupDir)
baseName = getTarBaseName.baseName // Doesn't work
extension = 'tar'
compression = Compression.NONE
}
task getTarBaseName() {
doFirst {
def result = BuildUtil.promptForName() // Uses Swing to prompt for a name
getTarBaseName.ext.baseName = result
}
}
As you can see I'm using ext to try to pass information between tasks, but that is just incidental not a requirement. Also I'm using 2 tasks, I'm completely willing to use only 1, however, that wouldn't really answer the general question which is one I hit against fairly often when attempting to use Gradle as a cross platform bash replacement for project related tasks.
To solve your specific problem (if I did not miss something), you don't need a second task. Just add a doFirst closure to your Tar task and set the baseName property there to whatever you want:
task saveDb(type: Tar) {
// static configuration
doFirst {
baseName = BuildUtil.promptForName()
// or for another task (don't forget to depend on that task)
baseName = otherTask.myProperty
}
}
task otherTask {
doFirst {
ext.myProperty = BuildUtil.promptForName()
}
}
However, your question boils down a general difficulty in Gradle: when to apply a specific piece of configuration.
Gradle just introduced a rather new feature for lazy configuration: Provider and Property
Gradle provides lazy properties, which delay the calculation of a property’s value until it’s absolutely required.
Before Gradle 4.0, only files could be lazy evaluated (via ConfigurableFileCollection), as an example:
task myZip(type: Zip) {
// zip some files
}
task copyMyZip(type: Copy) {
from myZip
}
myZip.baseName = 'myZip'
Even if the name of the zip file is defined after the Zip task is added to the Copy task configuration, its correct path will be used for the copy operation.
Now, with Gradle 4.0 and up, all configuration parameters that implement Property or Provider can be bound easily (check out the link above) and you can also lazily read a configuration parameter by wrapping it into a Provider, but it's difficult to put a provider value into an old configuration parameter. You still need to specify the moment when to evaluate (inside the task action, in a doFirst closure or an afterEvaluate handler). This problem is the topic of this discussion on GitHub.

Passing properties to a gradle build

I admit I am quite new to gradle but I did not expect to be unable to understand something as simple as the example below. I can read the gradle documentation about checking whether a project property have been set or not using a hasProperty(String propertyName) call and I am sitting here and have no idea why something so basic does not work.
I believe my mind must be so much "ant like" oriented that for sure I am missing something ordinary basic
task printSystem() << {
println system
println "has property: " + hasProperty("system")
}
and invoking that task with the command below:
$gradle printSystem -Psystem=mySystem
mySystem
has property: null
So my questions would be:
Why system is printed out but hasProperty returns null?
How should I check for the existence of the project property called "system"?
Is there a different way for testing for a project property as opposed to a system property?
How would you pass a system property from the command line?
This is from, the gradle documentation and I believe I am reading it right
19.2.1. Checking for project properties
You can access a project property in your build script simply by using its name as you would use a variable. If this property does not exist, an exception will be thrown and the build will fail. If your build script relies on optional properties the user might set, perhaps in a gradle.properties file, you need to check for existence before you access them. You can do this by using the method hasProperty('propertyName') which returns true or false.
You need to explicitly invoke hasProperty on the project instance - without it, hasProperty is invoked on some local context. The following example works:
task printSystem() << {
println system
println "has property: " + project.hasProperty("system")
}
Because non-existing properties (system is not defined in the script) are taken from the project instance. If you won't pass the system property, an exception will be thrown on println.
project.hasProperty('propName')
Not sure if I understood right, but you can access project properties via the project instance and system properties via the System class.
Using -D switch - gradle -Dprop=value

Dynamically created task of type Copy is always UP-TO-DATE

I've prepared a very simple script, that illustrates the problem I see using Gradle 1.7 (need to stick with it because of some plugins not yet supporting newer versions).
I'm trying to dynamically create tasks each of which corresponds to a file in the project directory. This works fine, but the tasks I create never get executed as soon as I assign them type 'Copy'.
Here is my problem build.gradle:
file('templates').listFiles().each { File f ->
// THIS LINE DOES NOT WORK
task "myDist-${f.name}" (type: Copy) {
// NEXT LINE WORKS
//task "myDist-${f.name}" {
doLast {
println "MYDIST-" + f.name
}
}
}
task distAll(dependsOn: tasks.matching { Task task -> task.name.startsWith("myDist")}) {
println "MYDISTALL"
}
defaultTasks 'distAll'
in this way my tasks do not get executed when I call default task calling simply gradle:
MYDISTALL
:myDist-template1 UP-TO-DATE
:myDist-template2 UP-TO-DATE
:distAll UP-TO-DATE
BUILD SUCCESSFUL
If I remove type Copy from my dynamic task (uncommenting the line above), my tasks get executed:
MYDISTALL
:myDist-template1
MYDIST-template1
:myDist-template2
MYDIST-template2
:distAll
BUILD SUCCESSFUL
(You'll need to create a folder name templates in the same directory where build.gradle is located and put couple of empty files into there in order to run the test)
According to the debug output:
Skipping task ':myDist-template1' as it has no source files.
Skipping task ':myDist-template2' as it has no source files.
So how can I specify source files and make my Copy tasks execute?
I've tried adding
from( '/absolute/path/to/existing/file' ) {
into 'myfolder'
}
to the task body, I've tried assigning task's inputs.source file('/my/existing/file') with no success.
Could you please advise on how to modify my simple script leaving dynamic task creation and keeping my dynamic tasks of type Copy?
Thank you!
Edit:
All right, this way the task gets called:
file('templates').listFiles().each { File f ->
task "myDist-${f.name}" (type: Copy) {
from f
into 'dist'
doLast {
println "MYDIST-" + f.name
}
}
}
but it looks I must always specify from/into. It doesn't suffice to do that in the doLast{} body.
A Copy task only gets executed if it has something to copy. Telling it what to copy is part of configuring the task, and therefore needs to be done in the configuration phase, rather than the execution phase. These are very important concepts to understand, and you can read up on them in the Gradle User Guide or on the Gradle Forums.
doFirst and doLast blocks get executed in the execution phase, as part of executing the task. Both are too late to tell the task what to copy: doFirst gets executed immediately before the main task action (which in this case is the copying), but (shortly) after the skipped and up-to-date checks (which are based on the task's configuration). doLast gets executed after the main task action, and is therefore clearly too late.
I think the following Gradle User Guide quote answers my question the best:
Secondly, the copy() method can not honor task dependencies when a task is used as a copy source (i.e. as an argument to from()) because it's a method and not a task. As such, if you are using the copy() method as part of a task action, you must explicitly declare all inputs and outputs in order to get the correct behavior.
Having read most of the answers to "UP-TO-DATE" Copy tasks in gradle, it appears that the missing part is 'include' keyword:
task copy3rdPartyLibs(type: Copy) {
from 'src/main/jni/libs/'
into 'src/main/libs/armeabi/'
include '**/*.so'
}
Putting from and into as part of the doLast section does not work. An example of a working task definitions is:
task copyMyFile(type: Copy) {
def dockerFile = 'src/main/docker/Dockerfile'
def copyTo = 'build/docker'
from dockerFile
into copyTo
doLast {
println "Copied Docker file [$dockerFile] to [$copyTo]"
}
}
Not the behavior I was expecting.
Using gradle 3.2.1

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