Use cases¶
Core concepts¶
In one image better than in 100 words:
Channels¶
Channels are chains of processing, the nodes, which use or transform message content. A channel is specialised for a type of input and can be linked to an endpoint for incoming message.
A channel receive a message, process it and return the response.
Channels are main components of pypeman. When you want to process a message, you first create a channel then add nodes to process the message.
You can specify a message store (see below) at channel initialisation
if you want to save all processed message. Use message_store argument with
an instance of wanted message store.
- Add node with
.add(*nodes) - Duplicate path with
.fork() - Make alternative path with
.when(condition)
HttpChannel¶
TBD
FilewatcherChannel¶
TBD
TimeChannel¶
TBD
Nodes¶
A node is a processing unit in a chain.
To create a node, inherit form pypeman.nodes.Node and overide process(msg) method.
ThreadNode¶
TBD
LogNode¶
TBD
Messages¶
Message contains the core information processed by nodes and carried by channel. The message payload can be of any type: Json, Xml, Soap, Hl7, text, ...
Useful attributes:
- payload: The message content
- meta: Message metadata, should be used to add extra information about the payload
- context: Previous message can be saved in context dict for further access.
Endpoints¶
Endpoints are server instance used by channel to get message from net protocols like HTTP, Soap or HL7, .... They listen to a specific port for a specific protocol.
Message Stores¶
A Message store is really useful to keep a copy of all message sent to a channel. It’s like a log but with complete message data and metadata. This way you can trace all Processing or replay a specific message (Not implemented yet).
FileMessageStore¶
A FileMessageStore save all message in file in a directory hierachy.