A small gradle helper script to determine package name, version code and version name for android gradle projects, including flavors.

version.gradle

// Usage: gradle -q -I version.gradle showVersionInfo

class VersionHelper {
  String project;
  String packageName;
  String versionCode;
  String versionName;

  VersionHelper(project, config) {
    this(project, config.applicationId, config.versionCode, config.versionName);
  }

  VersionHelper(project, packageName, versionCode, versionName) {
    this.project = project;
    this.packageName = packageName;
    this.versionCode = versionCode;
    this.versionName = versionName;
  }

  VersionHelper withManifest(manifest) {
    if (!manifest.exists()) {
      return this;
    }
    if (packageName != null && versionCode != null && versionName != null) {
      // We already know everything
      return this;
    }
    def rootNode = new XmlParser().parse(manifest);
    return withManifestValues(rootNode.attribute("package"), 
      rootNode.attribute(new groovy.xml.QName("http://schemas.android.com/apk/res/android", "versionCode")),
      rootNode.attribute(new groovy.xml.QName("http://schemas.android.com/apk/res/android", "versionName")));
  }

  VersionHelper withManifestValues(packageName, versionCode, versionName) {
    return new VersionHelper(project,
      this.packageName == null ? packageName : this.packageName,
      this.versionCode == null ? versionCode : this.versionCode,
      this.versionName == null ? versionName : this.versionName);
  }

  VersionHelper withFlavor(flavor) {
    return withFlavor(flavor.name, flavor.hasProperty("applicationId") ? flavor.applicationId : null, flavor.versionCode, flavor.versionName);
  }
  
  VersionHelper withFlavor(flavorName, packageName, versionCode, versionName) {
    return new VersionHelper(project + "#" + flavorName,
      packageName == null ? this.packageName : packageName,
      versionCode == null ? this.versionCode : versionCode,
      versionName == null ? this.versionName : versionName);
  }

  String toString() {
    return "<application xmlns:android=\"http://schemas.android.com/apk/res/android\" " + 
      (project == null ? "" : "project=\"" + project + "\" ") + 
      (packageName == null ? "" : "package=\"" + packageName + "\" ") + 
      (versionCode == null ? "" : "android:versionCode=\"" + versionCode + "\" ") + 
      (versionName == null ? "" : "android:versionName=\"" + versionName + "\" ") + "/>";
  }
}

allprojects {
  task showVersionInfo << {
    if (project.hasProperty("android")) {
      VersionHelper version = new VersionHelper(project.name, android.defaultConfig);
      if (android.productFlavors.isEmpty()) {
        println version.withManifest(project.file(android.sourceSets.main.manifest.toString()));
      } else {
        android.productFlavors.each {
          VersionHelper flavor = version.withFlavor(it)
            .withManifest(project.file(android.sourceSets.getByName(it.name).manifest.toString()))
            .withManifest(project.file(android.sourceSets.main.manifest.toString()));
          println flavor;
        }
      }
    }
  }
}