When nesting an activity with multiple outcomes, you can wire each terminus to a different route.

For example, an output using Track(:create) will snap to the next possible task that is “magnetic to” :create. That’s how tracks or paths are created.

Semantics are mostly relevant for nesting

Remember, in a railway activity each task has two standard outputs with the “semantics” success and failure.

By using Output(:semantic), you can select an existing output of the task and rewire it.

Why don’t we put the “create user” task onto the failure track, and in case of successfully persisting the new user, we deviate back to the happy path?

To implement such an activity, we only need to rewire the second step’s failure output to a new terminus.

Since you can reference outputs by their semantic, you as a modeller only connect conceptual termini to ongoing connections!

it’s a bit as if the following wiring is applied to every task added via #step