Following a correlation set in an orchestration

I always thought the "Follow correlation set" property on a send shape does not make much sense, after all it is only a receive shape that is really expected to follow a correlation set initialized earlier in the process.

Today I found what it’s useful for.

I knew setting a context property's value in an orchestration keeps it in a "Not Promoted" state. I also got used to initializing a correlation set when sending messages to the message box when I needed to promote certain properties, which is a bit awkward I guess, but is common knowledge.

However - this time I needed to post messages to the message box through a directly bound send port while promoting a couple of properties to allow the messages to be routed correctly from the message box.

With the send shape being in a loop I could not initialize the correlation set there as you're not allowed to initialize a correlation set more then once.

The answer was very simple, but not obvious (I hope, otherwise it’s just a case of me being thick), you can use the "follow correlation set" on a send shape, which, like the initialize correlation set, will make sure the properties defined in the correlation type gets promoted.

Unlike the "initialize correlation set" this can be done as many times as needed.

I guess this is nothing new or surprising to many, but it was for me, which makes it worth posting.