clojurescriptmadeeasy.com/blog/real-world-core-async.html

real-world-core-async.cljs

(ns cljsmadeeasy.core
  (:require [cljs.core.async :as a])
  (:require-macros [cljs.core.async.macros :refer [go]]))

(defn fill-load-chan [number-of-pages]
  (let [partitions (partition-all NUM-PAGES-PER-LOAD
                                  (range 1 (inc number-of-pages)))
        c (a/chan)]
    (go
      (doseq [page-numbers partitions]
        (a/>! c page-numbers))
      (a/close! c))
    c))

(defn load-from-chan [c]
  (go
    (loop []
      (when-let [page-numbers (a/<! c)]
        (doseq [page-number page-numbers]
          (load-page! page-number))
        (a/<! (a/timeout WAIT-BETWEEN-LOAD))
        (recur)))))

(defn load-specific-page [c-mix page-number]
  (let [c (a/chan)]
    (a/toggle queue-mix {c {:solo true}})
    (a/put! c [page-number])
    (a/close! c))
  
(def main-chan (a/chan))
(def c-mix (a/mix main-chan))

(a/admix c-mix (fill-load-chan num-pages))
(load-from-chan main-chan))

;;load a specific page when needed
(load-specific-page c-mix page-number)