final class methodTag[BaseTag <: RpcTag] extends Annotation with RawRpcAnnotation

Method tagging lets you have more explicit control over which raw methods can match which real methods. Example:

sealed trait MethodType extends RpcTag
class GET extends RestMethod
class POST extends RestMethod

@methodTag[MethodType](new GET)
trait ExampleRawRpc {
  @tagged[GET] def get(@methodName name: String, @multi args: Map[String,Json]): Future[Json]
  @tagged[POST] def post(@methodName name: String, @multi args: Map[String,Json]): Future[Json]
}

In the example above, we created a hierarchy of annotations rooted at MethodType which can be used on real methods in order to explicitly tell the RPC macro which raw methods can match it. We also specify new GET as the default tag that will be assumed for real methods without any tag annotation. Then, using tagged we specify that the raw get method may only match real methods annotated as GET while post raw method may only match real methods annotated as POST. Raw methods not annotated with tagged have no limitations and may still match any real methods.

Also, instead of specifying defaultTag in @methodTag annotation, you may provide the whenUntagged parameter to tagged annotation. Raw method annotated as @tagged[MethodType](whenUntagged = new GET) will match real methods either explicitly tagged with GET or untagged. If untagged, new GET will be assumed as the tag. This is useful when you want to have multiple raw methods with different whenUntagged setting.

NOTE: The example above assumes there is a Json type defined with appropriate encodings - see encoded for more details on parameter and method result encoding.

An example of real RPC for ExampleRawRpc:

trait ExampleApi {
  def getUser(id: UserId): Future[User]
  @POST def saveUser(user: User): Future[Unit]
}
object ExampleApi {
  implicit val AsRawReal: AsRawReal[ExampleRawRpc,ExampleApi] = AsRawReal.materialize
}
BaseTag

base type for tags that can be used on real RPC methods

Linear Supertypes
RawRpcAnnotation, RawSymAnnotation, StaticAnnotation, Annotation, AnyRef, Any
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Inherited
  1. methodTag
  2. RawRpcAnnotation
  3. RawSymAnnotation
  4. StaticAnnotation
  5. Annotation
  6. AnyRef
  7. Any
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Visibility
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Instance Constructors

  1. new methodTag(defaultTag: BaseTag = null)

    defaultTag

    default tag value assumed for untagged methods

Value Members

  1. val defaultTag: BaseTag