=doc #3564 Moving the Actor DSL doc section

This commit is contained in:
Marcus Ljungblad 2013-12-17 12:21:52 -05:00
parent b8c7d7badd
commit 189f4888eb
3 changed files with 87 additions and 73 deletions

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@ -0,0 +1,80 @@
.. _actordsl-scala:
################
Actor DSL
################
The Actor DSL
=============
Simple actors—for example one-off workers or even when trying things out in the
REPL—can be created more concisely using the :class:`Act` trait. The supporting
infrastructure is bundled in the following import:
.. includecode:: ../../../akka-actor-tests/src/test/scala/akka/actor/ActorDSLSpec.scala#import
This import is assumed for all code samples throughout this section. The
implicit actor system serves as :class:`ActorRefFactory` for all examples
below. To define a simple actor, the following is sufficient:
.. includecode:: ../../../akka-actor-tests/src/test/scala/akka/actor/ActorDSLSpec.scala#simple-actor
Here, :meth:`actor` takes the role of either ``system.actorOf`` or
``context.actorOf``, depending on which context it is called in: it takes an
implicit :class:`ActorRefFactory`, which within an actor is available in the
form of the ``implicit val context: ActorContext``. Outside of an actor, youll
have to either declare an implicit :class:`ActorSystem`, or you can give the
factory explicitly (see further below).
The two possible ways of issuing a ``context.become`` (replacing or adding the
new behavior) are offered separately to enable a clutter-free notation of
nested receives:
.. includecode:: ../../../akka-actor-tests/src/test/scala/akka/actor/ActorDSLSpec.scala#becomeStacked
Please note that calling ``unbecome`` more often than ``becomeStacked`` results
in the original behavior being installed, which in case of the :class:`Act`
trait is the empty behavior (the outer ``become`` just replaces it during
construction).
Life-cycle management
---------------------
Life-cycle hooks are also exposed as DSL elements (see :ref:`start-hook-scala` and :ref:`stop-hook-scala`), where later invocations of the methods shown below will replace the contents of the respective hooks:
.. includecode:: ../../../akka-actor-tests/src/test/scala/akka/actor/ActorDSLSpec.scala#simple-start-stop
The above is enough if the logical life-cycle of the actor matches the restart
cycles (i.e. ``whenStopping`` is executed before a restart and ``whenStarting``
afterwards). If that is not desired, use the following two hooks (see :ref:`restart-hook-scala`):
.. includecode:: ../../../akka-actor-tests/src/test/scala/akka/actor/ActorDSLSpec.scala#failing-actor
It is also possible to create nested actors, i.e. grand-children, like this:
.. includecode:: ../../../akka-actor-tests/src/test/scala/akka/actor/ActorDSLSpec.scala#nested-actor
.. note::
In some cases it will be necessary to explicitly pass the
:class:`ActorRefFactory` to the :meth:`actor()` method (you will notice when
the compiler tells you about ambiguous implicits).
The grand-child will be supervised by the child; the supervisor strategy for
this relationship can also be configured using a DSL element (supervision
directives are part of the :class:`Act` trait):
.. includecode:: ../../../akka-actor-tests/src/test/scala/akka/actor/ActorDSLSpec.scala#supervise-with
Actor with :class:`Stash`
-------------------------
Last but not least there is a little bit of convenience magic built-in, which
detects if the runtime class of the statically given actor subtype extends the
:class:`RequiresMessageQueue` trait via the :class:`Stash` trait (this is a
complicated way of saying that ``new Act with Stash`` would not work because its
runtime erased type is just an anonymous subtype of ``Act``). The purpose is to
automatically use the appropriate deque-based mailbox type required by :class:`Stash`.
If you want to use this magic, simply extend :class:`ActWithStash`:
.. includecode:: ../../../akka-actor-tests/src/test/scala/akka/actor/ActorDSLSpec.scala#act-with-stash

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@ -194,79 +194,6 @@ are described in more depth in the
guideline and the `Akka Java Spring <http://typesafe.com/activator/template/akka-java-spring>`_ tutorial
in Typesafe Activator.
The Actor DSL
-------------
Simple actors—for example one-off workers or even when trying things out in the
REPL—can be created more concisely using the :class:`Act` trait. The supporting
infrastructure is bundled in the following import:
.. includecode:: ../../../akka-actor-tests/src/test/scala/akka/actor/ActorDSLSpec.scala#import
This import is assumed for all code samples throughout this section. The
implicit actor system serves as :class:`ActorRefFactory` for all examples
below. To define a simple actor, the following is sufficient:
.. includecode:: ../../../akka-actor-tests/src/test/scala/akka/actor/ActorDSLSpec.scala#simple-actor
Here, :meth:`actor` takes the role of either ``system.actorOf`` or
``context.actorOf``, depending on which context it is called in: it takes an
implicit :class:`ActorRefFactory`, which within an actor is available in the
form of the ``implicit val context: ActorContext``. Outside of an actor, youll
have to either declare an implicit :class:`ActorSystem`, or you can give the
factory explicitly (see further below).
The two possible ways of issuing a ``context.become`` (replacing or adding the
new behavior) are offered separately to enable a clutter-free notation of
nested receives:
.. includecode:: ../../../akka-actor-tests/src/test/scala/akka/actor/ActorDSLSpec.scala#becomeStacked
Please note that calling ``unbecome`` more often than ``becomeStacked`` results
in the original behavior being installed, which in case of the :class:`Act`
trait is the empty behavior (the outer ``become`` just replaces it during
construction).
Life-cycle hooks are also exposed as DSL elements (see `Start Hook`_ and `Stop
Hook`_ below), where later invocations of the methods shown below will replace
the contents of the respective hooks:
.. includecode:: ../../../akka-actor-tests/src/test/scala/akka/actor/ActorDSLSpec.scala#simple-start-stop
The above is enough if the logical life-cycle of the actor matches the restart
cycles (i.e. ``whenStopping`` is executed before a restart and ``whenStarting``
afterwards). If that is not desired, use the following two hooks (see `Restart
Hooks`_ below):
.. includecode:: ../../../akka-actor-tests/src/test/scala/akka/actor/ActorDSLSpec.scala#failing-actor
It is also possible to create nested actors, i.e. grand-children, like this:
.. includecode:: ../../../akka-actor-tests/src/test/scala/akka/actor/ActorDSLSpec.scala#nested-actor
.. note::
In some cases it will be necessary to explicitly pass the
:class:`ActorRefFactory` to the :meth:`actor()` method (you will notice when
the compiler tells you about ambiguous implicits).
The grand-child will be supervised by the child; the supervisor strategy for
this relationship can also be configured using a DSL element (supervision
directives are part of the :class:`Act` trait):
.. includecode:: ../../../akka-actor-tests/src/test/scala/akka/actor/ActorDSLSpec.scala#supervise-with
Last but not least there is a little bit of convenience magic built-in, which
detects if the runtime class of the statically given actor subtype extends the
:class:`RequiresMessageQueue` trait via the :class:`Stash` trait (this is a
complicated way of saying that ``new Act with Stash`` would not work because its
runtime erased type is just an anonymous subtype of ``Act``). The purpose is to
automatically use the appropriate deque-based mailbox type required by :class:`Stash`.
If you want to use this magic, simply extend :class:`ActWithStash`:
.. includecode:: ../../../akka-actor-tests/src/test/scala/akka/actor/ActorDSLSpec.scala#act-with-stash
The Inbox
---------
@ -406,6 +333,8 @@ using ``context.unwatch(target)``. This works even if the :class:`Terminated`
message has already been enqueued in the mailbox; after calling :meth:`unwatch`
no :class:`Terminated` message for that actor will be processed anymore.
.. _start-hook-scala:
Start Hook
----------
@ -421,6 +350,8 @@ Initialization code which is part of the actors constructor will always be
called when an instance of the actor class is created, which happens at every
restart.
.. _restart-hook-scala:
Restart Hooks
-------------
@ -462,6 +393,8 @@ usual.
it has processed the last messages sent by the child before the failure.
See :ref:`message-ordering` for details.
.. _stop-hook-scala:
Stop Hook
---------

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@ -14,3 +14,4 @@ Actors
fsm
persistence
testing
actordsl