Local Chat Application with MultiPeerConnectivity.
The app opens a service via MultiPeerConnectivity and at the same time advertises itself as a peer and browses for other peers. If any peers are found, invitations are sent out automatically. Received invitations are accepted automatically.
Messages can then be send to all connected peers, sort of like a group chat.
No additional networking logic on top of MultiPeerConnectivity is implemented (yet).
All of the networking logic is contained in the WalkieTalkie folder which might later be refactored into a separate library.
The main component is the Communicator class. This is a generic class
encapsulating networking. You use this to send and receive messages.
Messages are serialized & deserialized using a combination of generic protocols.
Communicator is specialized on the CommunicatorOutput protocol. This can be
anything you like it to, e.g. in this application it represents a ChatEvent.
The CommunicatorOutput protocol also defines a payload type, which is the actual
object that will be sent over the wire.
Serialization is done via the CommunicatorPayload protocol. A payload has to
know how to represent itself as a dictionary and how to construct itself from
such a dictionary.
This dictionary is then sent over the wire and arrives on the other side. There
the Communicator creates a CommunicatorMessage object, which includes the
deserialized payload and some meta information (like the associated peer).
This message object is used to instantiate an CommunicatorOutput instance
which takes the message and transforms it into an application level object.
This all plays together to create a seamless serialisation & deserialisation logic without any action needed on the calling side.
For a concrete usage example please see the ChatRoom.swift file. There all the
application level objects for the chat are defined implementing the needed
protocols.