CloudEvents

[tfahringer]

CloudEvents is a major standard for events in the cloud-edge continuum. How could I connect CloudEvents with the generic events of SCXML.
Basically I want to use CloudEvents as the underlying event system for invoking and transferring events.
How can I interface to CloudEvents from SCXML?

[alexzhornyak]

There are 2 event processors that are described in SCXML standard:

• SCXML Event I/O Processor - The SCXML Event I/O Processor is intended to transport messages between SCXML sessions
• Basic HTTP Event I/O Processor - The Basic HTTP Event I/O Processor is intended as a minimal interoperable mechanism for sending and receiving events to and from external components and SCXML 1.0 implementations. Support for the Basic HTTP Event I/O Processor is optional.

NOTE: If your SCXML framework (uscxml, Qt scxml, scion etc.) allows you to register custom event processor you can do it according to framework documentation

Example of custom ZeroMQ based event processor overrided from uscxml framework SCXMLIOProcessor class

class ZmqIOProcessor : public SCXMLIOProcessor {
	ScxmlTask *m_ScxmlTask;
public:
	ZmqIOProcessor(IOProcessorCallbacks* callbacks, ScxmlTask *AScxmlTask);

	virtual std::list<std::string> getNames() override {
		std::list<std::string> names;
		names.push_back(protocol());
		return names;
	};

	virtual std::shared_ptr<IOProcessorImpl> create(IOProcessorCallbacks* callbacks) override;

	virtual void eventFromSCXML(const std::string& target, const Event& event) override {
		// sending received Event from state machine by ZeroMQ network service
	}

	static std::string protocol() { return "zmq_protocol"; }
};

Other uscxml framwork ioprocessor examples