ESB Guidance 101: File receive, dynamic endpoint resolution via rules engine

There was a message at the Codeplex site from someone having issues doing a simple "receive file from folder, do dynamic endpoint resolution and deliver message". I threw together a little sample showing how this works, and blogged about it in case others need this too.

The moving parts involved are:

• receive location using the ItineraryReceivePassthrough pipeline
• dynamic send port using the ItinerarySendPassthrough pipeline

How it works:

• the message is received
• the ESB Dispatcher Disassembler calls the Resolver specified in the Endpoint (in this sample, the business rules engine, see below)
• the Resolver invokes the rules policy
• the AdapterProvider framework sets appropriate outbound adapter information
• the message hits the MessageBox
• a send port subscribes to all messages from that specific receive location
• the message is delivered

The receive configuration looks like this:

(full endpoint value is "BRE:\\policy=Microsoft.Practices.ESB.Test;version=;useMsg=;MessageExchangePattern=;")

The send side looks like this (note that there are no values set in the per-instance properties):

Then, of course, we need a filter condition to link them together:

The ultra-complex rules policy :) looks like this: