add custom groovy plugin and its usage from local Maven storage

14-custom-groovy-plugin/build.gradle

@@ -0,0 +1,12 @@
+apply plugin: "groovy"
+apply plugin: "maven"
+
+archivesBaseName = "lines-count"
+version = "1.0"
+group "com.ysoft.training"
+
+dependencies {
+    compile localGroovy()
+    compile gradleApi()
+}
+

14-custom-groovy-plugin/src/main/groovy/com/ysoft/training/LineCountPlugin.groovy

@@ -0,0 +1,22 @@
+package com.ysoft.training
+
+import org.gradle.api.Plugin
+import org.gradle.api.Project
+import org.gradle.api.Task
+
+/**
+ * Simple plugin for counting lines in build.gradle.
+ **/
+class LineCountPlugin implements Plugin<Project> {
+
+    void apply(Project project) {
+        Task countLineTask = project.tasks.add("countLines")
+        countLineTask.doLast {
+            def counter = 0
+            new File("build.gradle").eachLine { line -> 
+                counter += 1
+            }
+            println "Total lines: ${counter}"
+        }
+    }
+}

14-custom-groovy-plugin/src/main/resources/META-INF/gradle-plugins/lines-count.properties

@@ -0,0 +1 @@
+implementation-class=com.ysoft.training.LineCountPlugin

15-use-custom-plugin/build.gradle

@@ -0,0 +1,11 @@
+buildscript {
+    repositories {
+        mavenLocal()
+    }
+    dependencies {
+        classpath 'com.ysoft.training:lines-count:1.0'
+    }
+}
+
+apply plugin: 'lines-count'
+

README.md

@@ -139,3 +139,27 @@ In this example plugin is stored as gist at Github
 
     gradle tasks
     gradle helloFromGist
+
+
+## 14-custom-groovy-plugin
+
+Example of stand alone plugin written in Groovy. Compile and install this
+plugin to your local Maven repository. Then you will be able to use it in
+the next example.
+
+    gradle install
+
+Pay attention to special file: src/main/resources/META-INF/gradle-pluginslines-count.properties
+This file will cause that it will be possible to apply plugin by it's id instead
+of java class name. It's preferred solution in Gradle world, because it gives
+you more flexibility when changing plugin implementation
+
+
+## 15-use-custom-plugin
+
+You need to install plugin to your local Maven storage (see example 14.).
+This example shows how to include plugin from local Maven storage.
+Plugin is just counting lines in build.gradle file in current directory.
+
+    gradle tasks
+    gradle countLines