66 lines
1.9 KiB
ReStructuredText
66 lines
1.9 KiB
ReStructuredText
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Implementing Custom Tasks
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=========================
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Introduction
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------------
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In this second tutorial we are going to implement our own task, and
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use serialization and deserialization to store and restore it.
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If you haven't already, you should complete the first
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:doc:`../tutorial/index`.
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We are also assuming that you are familiar with the :doc:`../basics`.
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Implementing the custom task
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----------------------------
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The first step is to create a :class:`SpiffWorkflow.specs.TaskSpec` that
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fires the rocket::
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from SpiffWorkflow.specs import Simple
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class NuclearStrike(Simple):
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def _on_complete_hook(self, my_task):
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print("Rocket sent!")
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Save this file as ``strike.py``.
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Now, before we are ready to define the workflow using XML or JSON, we will
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also have extend the serializer to let SpiffWorkflow know how to represent
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your NuclearStrike first.
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Preparing a serializer
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----------------------
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Before we can use JSON to specify a workflow, we first need to teach
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SpiffWorkflow what our custom `NuclearChoice` looks like in JSON.
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We do this by extending the
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:mod:`SpiffWorkflow.serializer.json.JSONSerializer`.
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.. literalinclude:: serializer.py
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We save the serializer as ``serializer.py``.
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We also need to update ``strike.py`` as follows:
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We also implement the deserializer:
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.. literalinclude:: strike.py
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That is all! You are now ready to create the specification from JSON.
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Creating a workflow specification (using JSON)
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----------------------------------------------
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Now we can use the NuclearStrike in the workflow specification in JSON.
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Note that this specification is the same as in our first tutorial,
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except that it references our class `strike.NuclearStrike`.
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.. literalinclude:: nuclear.json
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Using the custom serializer and task
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------------------------------------
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Here we use our brand new serializer in practice:
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.. literalinclude:: start.py
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