Use of Gradle Plugin in external .gradle file - gradle

Question

Background:
I'm trying to use the gradle-dependency-graph-generator-plugin in a gradle build, and configure it with custom Generator configurations. When I place the configuration within the _root.gradle, our root gradle project:
buildscript {
repositories {
maven {
url artifactoryRepoURL + '/repo'
}
}
dependencies {
//...
classpath "com.vanniktech:gradle-dependency-graph-generator-plugin:0.5.0"
}
}
//...
allprojects {
//...
apply plugin: "com.vanniktech.dependency.graph.generator"
//...
}
...it works just fine. (Though, Intellij reports errors in the import, it builds and runs both on command line and in the IDE)
The Problem
I'd like to put this code in a separate gradle file, just so it's not cluttering up the root project. So I move the code to a dependencyGraph.gradle file, and include it with an
apply from: "$rootProject.projectDir/dependencyGraph.gradle"
However, I get compilation errors, class not found. So I add the buildScript and dependencies/classpath from the root project file, and try again. This time, it gives a class cast exception:
com.vanniktech.dependency.graph.generator.DependencyGraphGeneratorExtension$Generator cannot be cast to com.vanniktech.dependency.graph.generator.DependencyGraphGeneratorExtension$Generator
Its the same classname, so I assume this is some kind of classloader problem. So, how does one include a build script that references plugin classes into a project.gradle?
EDIT:
Per – #EugenMartynov 's comment, the file looks like:
buildscript {
repositories {
maven {
url artifactoryRepoURL + '/repo'
}
}
dependencies {
classpath "com.vanniktech:gradle-dependency-graph-generator-plugin:0.5.0"
}
}
import com.vanniktech.dependency.graph.generator.DependencyGraphGeneratorPlugin
import com.vanniktech.dependency.graph.generator.DependencyGraphGeneratorExtension.Generator
import guru.nidi.graphviz.attribute.Color
import guru.nidi.graphviz.attribute.Style
import guru.nidi.graphviz.attribute.Label
def updateNode(node, dependency) {
def group = dependency.getModuleGroup()
def colorCodeFor = { starts, color ->
if (group.startsWith(starts)) {
node.add(Style.FILLED, Color.rgb(color))
return color
}
return null
}
def color = colorCodeFor("commons", "#ff008c")
?: colorCodeFor("org.apache", "#ff008c")
?: colorCodeFor("org.springframework", "#6db33f")
?: colorCodeFor("javax", "#ff0000")
?: colorCodeFor("com.fasterxml", "#3a772e")
?: colorCodeFor("ch.qos.logback", "#ffd0a0")
?: colorCodeFor("", String.format("#%06x", Math.abs(group.hashCode()) % (255*255*255))) // base off the group
return node
}
def colorCodedGenerator = new Generator(
"ColorCoded", // Suffix for our Gradle task.
{ dependency -> true }, // filter
{ dependency -> true }, // Include transitive dependencies.
{ node, dependency -> updateNode(node, dependency) }, // Give them some color.
{ node, project ->node.add(Style.FILLED, Color.rgb("#2cc2e4")) }, // project nodes.
)
dependencyGraphGenerator {
generators = [ Generator.ALL, colorCodedGenerator ]
}
and is applied within the allprojects block:
allprojects {
...
apply plugin: "com.vanniktech.dependency.graph.generator"
apply from: "$rootProject.projectDir/dependencyGraph.gradle"
...
}
though I also tried only within the root project. As configured, I get:
FAILURE: Build failed with an exception.
...
* What went wrong:
A problem occurred configuring root project 'dar'.
> com.vanniktech.dependency.graph.generator.DependencyGraphGeneratorExtension$Generator cannot be cast to com.vanniktech.dependency.graph.generator.DependencyGraphGeneratorExtension$Generator
This is gradle 4.9, btw