53 lines
1.5 KiB
ReStructuredText
53 lines
1.5 KiB
ReStructuredText
.. _extending-akka-scala:
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Akka Extensions
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===============
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.. sidebar:: Contents
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.. contents:: :local:
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Building an Extension
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---------------------
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So let's create a sample extension that just lets us count the number of times something has happened.
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First, we define what our ``Extension`` should do:
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.. includecode:: code/akka/docs/extension/ExtensionDocSpec.scala
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:include: imports,extension
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Then we need to create an ``ExtensionId`` for our extension so we can grab ahold of it.
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.. includecode:: code/akka/docs/extension/ExtensionDocSpec.scala
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:include: imports,extensionid
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Wicked! Now all we need to do is to actually use it:
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.. includecode:: code/akka/docs/extension/ExtensionDocSpec.scala
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:include: extension-usage
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Or from inside of an Akka Actor:
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.. includecode:: code/akka/docs/extension/ExtensionDocSpec.scala
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:include: extension-usage-actor
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You can also hide extension behind traits:
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.. includecode:: code/akka/docs/extension/ExtensionDocSpec.scala
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:include: extension-usage-actor-trait
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That's all there is to it!
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Loading from Configuration
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--------------------------
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To be able to load extensions from your Akka configuration you must add FQCNs of implementations of either ``ExtensionId`` or ``ExtensionIdProvider``
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in the "akka.extensions" section of the config you provide to your ``ActorSystem``.
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Applicability
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-------------
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The sky is the limit!
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By the way, did you know that Akka's ``Typed Actors``, ``Serialization`` and other features are implemented as Akka Extensions?
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