Participant check-in by receptionist should trigger web service call

[gregorwolf]

To print i.e. badges for the visitors it should be possible to call a web service. To allow devices to be connected via push rather than pull I will use the HCP IoT Services. It allows devices to establish a web socket connection.

To allow different devices (also multiple devices) for the same event a Device entity with the fields EventID, History, Active, DeviceID (Char Lengh 36 according to the HCP IoT Documentation for Device) needs to be created. This table is exposed in the OData service for the organizer. It can be maintained like the co-organizer table.

As the devices might not be able to send a confirmation back that i.e. the badge was printed also a table that queues the messages. This table should have the Columns ParticipantID, EventID, FirstName, LastName, Twitter, SendStatus, History. This table is exposed in the receptionist OData service. So the receptionist can confirm when the output is finished. Then the next in the queue can be sent.