34 – Properties and Providers

.github/workflows/build.yaml

@@ -51,4 +51,5 @@ jobs:
       - run: "gradle run   --warning-mode=fail -p 30_Security_Vulnerabilities/my-project"
       - run: "gradle run   --warning-mode=fail -p 31_The_Module_Path/my-project"
       - run: "gradle build --warning-mode=fail -p 32_Artifact_Transforms/my-project"
-      - run: "gradle build --warning-mode=fail -p 33_Classpath_and_Module_Path_in_Testing/my-project"
+      - run: "gradle build --warning-mode=fail -p 33_Classpath_and_Module_Path_in_Testing/my-project"
+      - run: "gradle build --warning-mode=fail -p 34_Properties_and_Providers/my-project"

34_Properties_and_Providers/README.MD

@@ -0,0 +1,21 @@
+# Understanding Gradle #34 – Properties and Providers
+
+**👇 click thumbnail to watch video**
+
+[<img src="https://onepiecesoftware.github.io/img/videos/34.png" width="640">](https://www.youtube.com/watch?v=n8Tgr4aLB18&list=PLWQK2ZdV4Yl2k2OmC_gsjDpdIBTN0qqkE)
+
+What are the Property and Provider concepts in Gradle and why were they introduced?
+
+## Explore this sample
+
+This sample is best explored in [IntelliJ IDEA](https://www.jetbrains.com/idea/download).
+Open **`34_Properties_and_Providers/my-project`** in IDEA and confirm with _Trust Project_.
+
+## Further readings
+
+* [Lazy Configuration](https://docs.gradle.org/current/userguide/lazy_configuration.html)
+* [Task Configuration using Properties](https://docs.gradle.org/current/userguide/custom_gradle_types.html#configuration_using_properties)
+
+## Need Gradle support?
+
+Contact me, if you need help with Gradle: [onepiece.Software](https://onepiece.software).

34_Properties_and_Providers/my-build-logic/java-plugins/build.gradle.kts

@@ -0,0 +1,3 @@
+plugins {
+    `kotlin-dsl`
+}

34_Properties_and_Providers/my-build-logic/java-plugins/src/main/kotlin/my-java-application.gradle.kts

@@ -0,0 +1,30 @@
+import org.example.ApplicationReportTask
+
+plugins {
+    id("application")
+}
+
+tasks.named("assemble") // access existing task
+tasks.register("checkAll") // register new task
+tasks.withType<JavaCompile>().configureEach {  } // configure all of a certain type
+
+layout.projectDirectory
+layout.buildDirectory
+
+providers.environmentVariable("CI").orElse("false").get().toBoolean()
+providers.gradleProperty("foo") // pass to build via -Pfoo=bar
+providers.systemProperty("file.encoding")
+
+version = providers.fileContents(layout.projectDirectory.file("version.txt"))
+    .asText.get()
+
+val fileCollection: FileCollection = configurations.runtimeClasspath.get()
+fileCollection.elements.map { it.first().asFile }
+
+
+val main = application.mainClass.map { "$it-report.txt" }
+
+tasks.register<ApplicationReportTask>("applicationReport") {
+    classesDir.set(tasks.compileJava.flatMap { it.destinationDirectory })
+    reportFile.set(layout.buildDirectory.file(main))
+}

34_Properties_and_Providers/my-build-logic/java-plugins/src/main/kotlin/org/example/ApplicationReportTask.kt

@@ -0,0 +1,36 @@
+package org.example
+
+import org.gradle.api.DefaultTask
+import org.gradle.api.file.DirectoryProperty
+import org.gradle.api.file.RegularFileProperty
+import org.gradle.api.tasks.InputDirectory
+import org.gradle.api.tasks.OutputFile
+import org.gradle.api.tasks.TaskAction
+
+abstract class ApplicationReportTask : DefaultTask() {
+
+    //abstract val p1: Property<String>
+    //abstract val p2: Property<Int>
+    //abstract val p3: Property<MyEnum>
+
+    //abstract val p4: SetProperty<String>
+    //abstract val p5: ListProperty<String>
+    //abstract val p6: MapProperty<String, String>
+
+    @get:InputDirectory
+    abstract val classesDir: DirectoryProperty
+
+    @get:OutputFile
+    abstract val reportFile: RegularFileProperty
+
+    @TaskAction
+    fun report() {
+        reportFile.get().asFile.writeText(
+        """
+            Application report:
+            ===================
+            Class File Count: ${classesDir.get().asFileTree.count()}
+        """.trimIndent())
+    }
+
+}

34_Properties_and_Providers/my-build-logic/java-plugins/src/main/kotlin/org/example/MyEnum.kt

@@ -0,0 +1,4 @@
+package org.example
+
+enum class MyEnum {
+}

34_Properties_and_Providers/my-build-logic/settings.gradle.kts

@@ -0,0 +1,5 @@
+dependencyResolutionManagement {
+    repositories.gradlePluginPortal()
+}
+
+include("java-plugins")

34_Properties_and_Providers/my-project/app/build.gradle.kts

@@ -0,0 +1,8 @@
+plugins {
+    id("my-java-application")
+}
+
+application {
+    // mainClassName = "org.example.app.App"
+    mainClass.set("org.example.app.App")
+}

34_Properties_and_Providers/my-project/app/src/main/java/org/example/app/App.java

@@ -0,0 +1,9 @@
+package org.example.app;
+
+public class App {
+
+    public static void main(String[] args) {
+        PrintUtil.print();
+    }
+}
+

34_Properties_and_Providers/my-project/app/src/main/java/org/example/app/PrintUtil.java

@@ -0,0 +1,7 @@
+package org.example.app;
+
+public class PrintUtil {
+    public static void print() {
+        System.out.println("\uD83E\uDDA5");
+    }
+}

34_Properties_and_Providers/my-project/app/version.txt

@@ -0,0 +1 @@
+1.34

34_Properties_and_Providers/my-project/settings.gradle.kts

@@ -0,0 +1,12 @@
+// Locations of Gradle plugins
+pluginManagement {
+    repositories.gradlePluginPortal()
+    includeBuild("../my-build-logic")
+}
+
+// Location of other components
+dependencyResolutionManagement {
+    repositories.mavenCentral()
+}
+
+include("app")

README.MD

@@ -60,6 +60,10 @@ This gives you a general understanding of how things work in Gradle and enables
 32. [Artifact Transforms](32_Artifact_Transforms)
 33. [Classpath and Module Path in Testing](33_Classpath_and_Module_Path_in_Testing)
 
+## More Fundamentals (Entries 34 - ??)
+
+34. [Properties and Providers](34_Properties_and_Providers)
+
 ## Need Gradle support?
 
 Contact me, if you need help with Gradle: [onepiece.Software](http://onepiece.software).