Gradle plugin for XML Beans - gradle

I am trying to write a Gradle plugin for XML Beans. I have started with one of the 'Hello from Gradle' plugin examples, and also a plugin published by R. Artavia here. That plugin went straight to jar - I am trying to only generate source. The generated source must then be compiled with other project source and included in a single jar. Other goals include
- full plugin - all I should need is "apply plugin: 'xmlbean'"
- I can configure source/code gen location and some features if I want to
- It detects whether it needs to be rebuilt. (well, eventually!!!)
I am off to a pretty good start, but am blocked defining a new sourceSet. I am getting an error "No such property 'srcDirs'" (or 'srcDir'). It seems there is something I have to define someplace to make a new sourceSet work but I cannot find it. I have tried several different syntaxes (with/without equal sign, brackets, srcDir/srcDirs, etc. - nothing is working...
What do I need to do inside a plugin to make a new sourceSet entry be properly recognized?
Thank you!
JKE
File: xmlbean.gradle (includes greeting plugin for the moment for debugging)
apply plugin: xmlbean
apply plugin: 'java'
xmlbean {
message = 'Hi'
greeter = 'Gradle'
}
class xmlbean implements Plugin<Project> {
void apply(Project project) {
project.extensions.create("xmlbean", xmlbeanExtension)
Task xmlbeanTask = project.task('xmlbean')
xmlbeanTask << {
project.configurations {
xmlbeans
}
project.dependencies {
xmlbeans 'org.apache.xmlbeans:xmlbeans:2.5.0'
}
project.sourceSets {
main {
java {
srcDirs += '$project.buildDir/generated-source/xmlbeans'
}
}
xmlbeans {
srcDirs = ['src/main/xsd']
}
}
ant.taskdef(name: 'xmlbean',
classname: 'org.apache.xmlbeans.impl.tool.XMLBean',
classpath: project.configurations.xmlbeans.asPath)
ant.xmlbean(schema: project.sourceSets.xmlbean.srcDir,
srconly: true,
srcgendir: "$project.buildDir/generated-sources/xmlbeans",
classpath: project.configurations.xmlbeans.asPath)
println "${project.xmlbean.message} from ${project.xmlbean.greeter}"
}
project.compileJava.dependsOn(xmlbeanTask)
}
}
class xmlbeanExtension {
String message
String greeter
}
File: build.gradle
apply from: '../gradle/xmlbeans.gradle'
dependencies {
compile "xalan:xalan:$ver_xalan",
":viz-common:0.0.1",
":uform-repository:0.1.0"
}
Console: Error message:
:idk:xmlbean FAILED
FAILURE: Build failed with an exception.
* Where:
Script 'C:\jdev\cpc-maven\try.g2\comotion\gradle\xmlbeans.gradle' line: 32
* What went wrong:
Execution failed for task ':idk:xmlbean'.
> No such property: srcDirs for class: org.gradle.api.internal.tasks.DefaultSourceSet_Decorated
...
BUILD FAILED
Gradle info: version 2.5 / groovy 2.3.10 / JVM 7u55 on Windows 7 AMD64

You should try to become familiar with the Gradle DSL reference guide, because it's a huge help in situations like this. For example, if you click on the sourceSets { } link in the left navigation bar, you're taken to this section on source sets.
From there, you'll discover that the sourceSets {} block is backed by a class, SourceSetContainer. The next level of configuration nested inside is backed by a SourceSet object, and then within that you have one or more SourceDirectorySet configurations. When you follow the link to SourceDirectorySet, you'll see that there are getSrcDirs() and setSrcDirs() methods.
So how does this help? If you look closely at the exception, you'll see that Gradle is saying it can't find a srcDirs property on DefaultSourceSet_Decorated, which you can hopefully infer is an instance of SourceSet. That interface does not have an srcDirs property. That's because your xmlbeans {} block is configuring a SourceSet, not a SourceDirectorySet. You need to add another nested configuration to gain access to srcDirs.
At this point, I'm wondering whether a new source set is the appropriate solution. Unfortunately it's not clear to me exactly what the plugin should be doing, so I can't offer any alternatives at this point.

Related

How can I call code from one subproject in a gradle tasks of another subproject?

I have a project with two subprojects.
One of these subprojects, "A", contains code that is being published to an artifact.
The other subproject, "B", has a task that needs to do exactly what one of the methods in A's code does. I can replicate the logic in groovy, but is there any way I can actually have my task in subproject B call the code that was compiled as part of subproject A?
I'd tried adding a buildscript block in B that added the artifact from A to the classpath:
buildscript {
dependencies {
classpath project(':subproject-a')
}
}
...but this gave me an error:
Cannot use project dependencies in a script classpath definition.
I don't believe I can move subproject-a to buildSrc, as I'm also publishing its artifact to a maven repository for other projects to use.
You have a chicken or egg problem where all of the Gradle project classloaders are resolved before any classes are compiled. This can be resolved using a custom configuration and a Classloader
Eg:
configurations {
custom
}
dependencies {
custom project(':subproject-a')
}
task customTask {
doLast {
def urls = configurations.custom.files.collect { it.toURI().toURL() }
ClassLoader cl = new java.net.URLClassLoader(urls as URL[])
Class myClass = cl.loadClass('com.foo.MyClass')
// assuming zero args constructor
Object myObject = myClass.newInstance()
// assuming method which accepts single String argument
java.lang.reflect.Method myMethod = myClass.getMethod('myMethodName', String.class)
myMethod.invoke(myObject, 'methodArg')
}
}

How to declare project artifacts in non-Java build?

I have multi-project Gradle build that contains also non-Java projects.
I want to declare the artifacts create by one such project in a way that I can use project/configuration dependencies to get them, e.g.
consumer:
dependencies {
myConf project(path: ':producer', configuration: 'myConf')
}
What I currently have is this:
producer:
configurations {
myConf
}
task produceFile {
//... somehow create the file...
outputs.file file('path/to/file')
}
artifacts.add('myConf', produceFile.outputs.files.singleFile, { builtBy produceFile })
Is there a better way to declare the artifact than my clumsy version?
I couldn't figure out a way to pass the task dependency from the artifact to the producing task in one go.
According to the documentation article on Legacy publishing and the javadoc on the ArtifactHandler, for your simple example it should be sufficient to just pass the task, as long as the task type extends AbstractArchiveTask (e.g. Zip or Jar):
artifacts.add('myConf', produceFile)
... or in the more Gradle-ish way:
artifacts {
myConf produceFile
}
The article mentioned above has another example, where a File is passed directly to the add method, which requires you to specify the task to build the file in the way you did in your example.
However, let me propose other ideas for syntax that may be experienced more 'lightweight':
artifacts {
myConf files(produceFile).singleFile { buildBy produceFile }
// or
myConf file: files(produceFile).singleFile, buildBy: [produceFile]
}
These two examples use the Project.files(...) method to resolve the output(s) of the task instead of accessing them manually. The second example makes use of the map syntax often provided by Gradle.
If you want to somehow standardize your way to publish your custom artifacts, I would propose to create a custom task type that offers any of the different arguments the ArtifactHandler can process as a method or property:
class MyTaskType extends DefaultTask {
// ... other stuff ... of course this should be part of a plugin
def getArtifact() {
return ... // either a (Configurable)PublishArtifact (if constructor is available) or a map representation
}
}
task produceFile(type: MyTaskType) {
// configure somehow
}
artifacts {
myConf produceFile.artifact
}

Are pmd, repositories etc tasks in Gradle

I am creating basic custom tasks in Gradle and learning how to extend them to do more complicated actions (Learning from here: https://docs.gradle.org/current/userguide/tutorial_using_tasks.html).
One of my reference projects, which I am extending to learn Gradle looks something like this
// pmd config
pmd {
ignoreFailures = false
reportsDir = file("$globalOutputDir/pmd")
toolVersion = toolVersions.pmdVersion
}
repositories {
mavenCentral()
}
task listSubProjects{
doLast{
println 'Searching in root dir `'
}
}
My question is around the pmd and repositories sections and why they don't have a clear qualifier like "task" on them but my listSubProjects requires a task qualifier? Are these inherited tasks from plugins and don't need a task qualifier?
The blocks that you see are task extensions, also discussed here.
A plugin creator can define extensions to allow users to configure a plugin:
// plugin code
class GreetingPluginExtension {
// default value
String message = 'Hello from GreetingPlugin'
}
// plugin code
class GreetingPlugin implements Plugin<Project> {
void apply(Project project) {
// Add the 'greeting' extension object
def extension = project.extensions.create('greeting', GreetingPluginExtension)
// Add a task that uses configuration from the extension object
...
}
}
In project.extensions.create('greeting',... the greeting block to be used later in build.gradle files is defined.
Then in user build.gradle files
apply plugin: GreetingPlugin
// Configure the extension
greeting.message = 'Hi from Gradle'
// Same effect as previous lines but with different syntax
greeting {
message = 'Hi from Gradle'
}
Often the name of the extension is chosen to be the same as the plugin and/or the task, which can make things confusing.

How to get dependencies from a gradle plugin using "api" or "implementation" directives

Background: Running Android Studio 3.0-beta7 and trying to get a javadoc task to work for an Android library (the fact that this is not available as a ready-made task in the first place is really strange), and I managed to tweak an answer to a different question for my needs, ending up with this code (https://stackoverflow.com/a/46810617/1226020):
task javadoc(type: Javadoc) {
failOnError false
source = android.sourceSets.main.java.srcDirs
// Also add the generated R class to avoid errors...
// TODO: debug is hard-coded
source += "$buildDir/generated/source/r/debug/"
// ... but exclude the R classes from the docs
excludes += "**/R.java"
// TODO: "compile" is deprecated in Gradle 4.1,
// but "implementation" and "api" are not resolvable :(
classpath += configurations.compile
afterEvaluate {
// Wait after evaluation to add the android classpath
// to avoid "buildToolsVersion is not specified" error
classpath += files(android.getBootClasspath())
// Process AAR dependencies
def aarDependencies = classpath.filter { it.name.endsWith('.aar') }
classpath -= aarDependencies
aarDependencies.each { aar ->
System.out.println("Adding classpath for aar: " + aar.name)
// Extract classes.jar from the AAR dependency, and add it to the javadoc classpath
def outputPath = "$buildDir/tmp/exploded-aar/${aar.name.replace('.aar', '.jar')}"
classpath += files(outputPath)
// Use a task so the actual extraction only happens before the javadoc task is run
dependsOn task(name: "extract ${aar.name}").doLast {
extractEntry(aar, 'classes.jar', outputPath)
}
}
}
}
// Utility method to extract only one entry in a zip file
private def extractEntry(archive, entryPath, outputPath) {
if (!archive.exists()) {
throw new GradleException("archive $archive not found")
}
def zip = new java.util.zip.ZipFile(archive)
zip.entries().each {
if (it.name == entryPath) {
def path = new File(outputPath)
if (!path.exists()) {
path.getParentFile().mkdirs()
// Surely there's a simpler is->os utility except
// the one in java.nio.Files? Ah well...
def buf = new byte[1024]
def is = zip.getInputStream(it)
def os = new FileOutputStream(path)
def len
while ((len = is.read(buf)) != -1) {
os.write(buf, 0, len)
}
os.close()
}
}
}
zip.close()
}
This code tries to find all dependency AAR:s, loops through them and extracts classes.jar from them, and puts them in a temp folder that is added to the classpath during javadoc generation. Basically trying to reproduce what the really old android gradle plugin used to do with "exploded-aar".
However, the code relies on using compile dependencies. Using api or implementation that are recommended with Gradle 4.1 will not work, since these are not resolvable from a Gradle task.
Question: how can I get a list of dependencies using the api or implementation directives when e.g. configuration.api renders a "not resolvable" error?
Bonus question: is there a new, better way to create javadocs for a library with Android Studio 3.0 that doesn't involve 100 lines of workarounds?
You can wait for this to be merged:
https://issues.apache.org/jira/browse/MJAVADOC-450
Basically, the current Maven Javadoc plugin ignores classifiers such as AAR.
I ran in to the same problem when trying your answer to this question when this error message kept me from resolving the implementation dependencies:
Resolving configuration 'implementation' directly is not allowed
Then I discovered that this answer has a solution that makes resolving of the implementation and api configurations possible:
configurations.implementation.setCanBeResolved(true)
I'm not sure how dirty this workaround is, but it seems to do the trick for the javadocJar task situation.

Access to project configuration in a Gradle plugin task -> cannot determine dependencies of task

I'm trying to write a plugin to stuff all dependencies (unzipped) into the same jar. This is what I've tried:
apply plugin: CustomZipPlugin
class CustomZipPlugin implements Plugin<Project>{
void apply(Project project) {
project.configurations.add('include');
project.tasks.add(
name:'customZipTask', type: Zip)
{
from {project.configurations.include.collect{zipTree(it)}}
};
}
}
repositories{mavenCentral()}
dependencies{
include 'net.sourceforge.cobertura:cobertura:1.9.4.1'
}
This leads to: Cannot determine the dependencies of task ':customZipTask'
I also tried:
..
from project.configurations.include.collect{zipTree(it)}
..
This led to a: You can't change a configuration which is not in unresolved state!
However ... writing a custom task directly in my build script (instead of a build script) works .. i.e.:
task customZipTask(type: Zip){
from {project.configurations.include.collect{zipTree(it)}}
}
Any suggestions on how to implement this zip code in a plugin instead ? (preferably a non-hacky solution)
Aha!! I needed to prepend zipTree with 'project' .. that solved the problem. The error messages listed above were a bit misleading.
..
from project.configurations.include.collect{project.zipTree(it)}
..
How about println'ing all configurations ??
How would I fix the following? ( get a can't change configuration which is not resolved exception )
..
project.configurations.include.each {println it}
..

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