diff options
Diffstat (limited to 'src/main/scala/xyz/driver/core/init/BuildInfoReflection.scala')
-rw-r--r-- | src/main/scala/xyz/driver/core/init/BuildInfoReflection.scala | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/src/main/scala/xyz/driver/core/init/BuildInfoReflection.scala b/src/main/scala/xyz/driver/core/init/BuildInfoReflection.scala new file mode 100644 index 0000000..0e53085 --- /dev/null +++ b/src/main/scala/xyz/driver/core/init/BuildInfoReflection.scala @@ -0,0 +1,37 @@ +package xyz.driver.core +package init + +import scala.reflect.runtime +import scala.util.Try +import scala.util.control.NonFatal + +/** Utility object to retrieve fields from static build configuration objects. */ +private[init] object BuildInfoReflection { + + final val BuildInfoName = "xyz.driver.BuildInfo" + + lazy val name: String = get[String]("name") + lazy val version: Option[String] = find[String]("version") + + /** Lookup a given field in the build configuration. This field is required to exist. */ + private def get[A](fieldName: String): A = + try { + val mirror = runtime.currentMirror + val module = mirror.staticModule(BuildInfoName) + val instance = mirror.reflectModule(module).instance + val accessor = module.info.decl(mirror.universe.TermName(fieldName)).asMethod + mirror.reflect(instance).reflectMethod(accessor).apply().asInstanceOf[A] + } catch { + case NonFatal(err) => + throw new RuntimeException( + s"Cannot find field name '$fieldName' in $BuildInfoName. Please define (or generate) a singleton " + + s"object with that field. Alternatively, in order to avoid runtime reflection, you may override the " + + s"caller with a static value.", + err + ) + } + + /** Try finding a given field in the build configuration. If the field does not exist, None is returned. */ + private def find[A](fieldName: String): Option[A] = Try { get[A](fieldName) }.toOption + +} |