Typesafe injector

src/main/scala/com/greencatsoft/angularjs/core/Injector.scala

@@ -1,11 +1,35 @@
 package com.greencatsoft.angularjs.core
 
-import com.greencatsoft.angularjs.injectable
+import com.greencatsoft.angularjs.{injectable, internal}
+import com.greencatsoft.angularjs.internal.ServiceProxy
 
+import scala.language.experimental.macros
+import scala.reflect.macros.blackbox.Context
 import scala.scalajs.js
 
 @injectable("$injector")
 @js.native
 trait Injector extends js.Object {
-  def get(name: String): js.Object = js.native
+  def get[A](name: String): A = js.native
 }
+
+/** Supports easy, type safe injection of types annotated with `@injectable`.
+  *
+  * See example:
+  * {{{
+  * implicit val injector = Angular.injector("ng", "myModule")
+  * val compile = Injector.get[Compile]
+  * val rootScope = Injector.get[RootScope]
+  * }}}
+  */
+object Injector {
+  /** Gets an instance of the specified type from the provided injector.
+    *
+    * Fails at compile time, if the type isn't annotated with `@injectable`.
+    *
+    * @param injector the injector to retrieve the type from
+    * @tparam A the type to return an instance of
+    * @return instance of the specified type provided by the injector
+    */
+  def get[A](implicit injector: Injector): A = macro internal.Injector.get[A]
+}

src/main/scala/com/greencatsoft/angularjs/internal/Injector.scala

@@ -0,0 +1,18 @@
+package com.greencatsoft.angularjs.internal
+
+import com.greencatsoft.angularjs.core
+
+import scala.reflect.macros.blackbox.Context
+
+private[angularjs] object Injector {
+
+  def get[A](c: Context)(injector: c.Expr[core.Injector])(implicit tag: c.WeakTypeTag[A]): c.Expr[A] = {
+    import c.universe._
+
+    val name = ServiceProxy.identifierFromType(c)(tag.tpe) getOrElse {
+      c.abort(c.enclosingPosition, s"The specified type '${tag.tpe}' does not have @injectable annotation.")
+    }
+    val nameExpr = c.Expr[String](q"$name")
+    reify { injector.splice.get[A](nameExpr.splice) }
+  }
+}