This is my introduction to Stuart Sierra's Component library and the reloaded workflow, given at the aarhus.clj meetup #3.

This is where we left off after mettup #2; a functioning webservice with an internal storage to hold integers.

We will convert this example to use the component library in four steps, with a bonus fifth step. Each step isolates one part of the service and plugs it into what will become the final system.

Since the run-server function is at the heart of our little webservice, this is where we begin.

Because of the operations on the store found inside the call to defroutes we know the routes have to be componentified before the store.

Finally we can integrate the store into our component system. This also concludes the rewriting of our actual application logic.

In order to use all the work we did in the first three steps for anything useful, we need to inject some code in our REPL. This is done by adding a file containing the namespace user to the source path.

When developing component systems, individual parts often acquire connections to external services. Such connections may need to be terminated properly to let the external service know your system is no longer using it.