manifold.lifecycle — spootnik/maniflow 0.1.5

Convention based lifecycle management of asynchronous chains. This implements a lightweight take on the ideas behind interceptors and similar libraries.

Notable differences are:

• Manifold is the sole provided execution model for chains
• No chain manipulation can occur
• Guards and finalizer for steps are optional
• Exceptions during lifecycle steps stop the execution

run clj

(run init steps)

(run init steps {:keys [initialize augment executor] :as opts})

Run a series of potentially asynchronous steps in sequence on an initial value (init0, threading each step's result to the next step as input.

Steps are maps or the following keys:

[:id :handler :in :out :discard? :guard]

• id is the unique ID for a step
• handler is the function of the previous result
• in when present determines which path in the context will be fed to the handler. The handler is considered a function of the contex
• out when present determines which path in the context to associate the result to, otherwise replaces the full context
• discard? when present, runs the handler but pass the context untouched to the next step
• guard is an optional predicate of the current context and previous preventing execution of the step when yielding false

In the three-arity version, an extra options maps can be provided, with the following keys:

[:augment :executor]

• augment is a function called on the context for each step, expected to yield an updated context. This can useful to perform timing tasks
• executor a manifold executor to execute deferreds on

step clj

(step handler)

(step id handler & {:as params})

Convenience function to build a step map. Requires and ID and handler, and can be fed additional options

step* clj

(step* id handler {:keys [in out lens guard discard?]})

Convenience function to build a step map. Requires and ID and handler, and can be fed additional options