HOSTING NON-MESSAGING WORKFLOWS IN A MESSAGING HOST

A workflow hosting system is described herein that allows non-messaging workflows to be hosted by a message-based service host. The system provides a host implementation, which can be used to host non-messaging workflows, or workflows that either do not begin with a message activity or do not use messaging activities at all. When the host receives a message for a workflow service, if it is not already running (or persisted), the system creates a new workflow service instance. If a workflow does not begin with a message activity, it cannot be started by sending a message because there is no activity to receive the message. To host a non-messaging workflow, the system provides a translation layer that sits between the communication layer and the workflow with methods that a developer can override to correctly activate the workflow.