Components

gistfile1.clj

(ns component.core
  (:require [com.stuartsierra.component :as component]))

(defrecord AppConfig [file path]
  component/Lifecycle

  (start [this]
    (println "Starting AppConfig!")
    this)

  (stop [this]
    (println "Stopping AppConfig!")
    this))

(defn app-config [filename]
  (map->AppConfig {:file filename :path filename}))

(defrecord Database [connection config]
  component/Lifecycle

  (start [this]
    (println "Starting Database!")
    this)

  (stop [this]
    (println "Stopping Database!")
    this))

(defn database [host port]
  (map->Database {:connection {:host host :port port}}))

(defrecord Billing [config]
  component/Lifecycle

  (start [this]
    (println "Starting Billing!")
    this)

  (stop [this]
    (println "Stopping Billing!")
    this))

(defn billing []
  (map->Billing {}))

(defrecord Payments [config db billing]
  component/Lifecycle

  (start [this]
    (println "Starting Payments!")
    this)

  (stop [this]
    (println "Stopping Payments!")
    this))

(defn payments []
  (map->Payments {}))

(defn- system [config-file host port]
  (component/system-map
   :billing (component/using (billing)
                             {:config :configuration})
   :cassandra (component/using (database host port)
                               {:config :configuration})
   :configuration (app-config config-file)
   :payments (component/using (payments)
                              {:config :configuration
                               :db :cassandra
                               :billing :billing})))

(defn -main [& args]
  (component/start (system "file.cfg" "localhost" 1234)))