Waltz is a ClojureScript library that helps manage state in client-side applications using non-deterministic finite state machines.
Here's an example using waltz, crate, jayq, and fetch:
(ns metrics.client.main
(:require [waltz.state :as state]
[crate.core :as crate]
[fetch.lazy-store :as store])
(:use [jayq.core :only [append $ find show hide inner add-class remove-class]]
[waltz.state :only [trigger]])
(:use-macros [waltz.macros :only [in out defstate defevent]]
[crate.macros :only [defpartial]]))
(defn wait [ms func]
(js* "setTimeout(~{func}, ~{ms})"))
(def $container ($ :#metricsContainer))
(defpartial metric [{:keys [klass label]}]
[:div {:class (str "metric " klass)}
[:p.loading "Loading..."]
[:h1.value "..."]
[:h2 label]])
(defn add-metric [params]
(let [$elem ($ (metric params))
$loading (find $elem :.loading)
$value (find $elem :.value)
delay (or (:delay params) 10000)
me (state/machine (:label params))]
(defstate me :loading
(in [] (show $loading))
(out [] (hide $loading)))
(defstate me :normal
(in [v]
(inner $value v)
(wait delay #(trigger me :update))))
(defevent me :update []
(state/set me :loading)
(store/latest [:metrics (:metric params)]
#(trigger me :set %)))
(defevent me :set [v]
(state/unset me :loading)
(state/set me :normal v))
(trigger me :update)
(append $container $elem)
me))
(add-metric {:label "Views today" :klass "gray"})
(add-metric {:label "Signups today" :delay 30000 :klass "gray"})
(add-metric {:label "Signups today" :delay 30000 :klass "gray"})
(add-metric {:label "Signups today" :delay 30000 :klass "gray"})
(add-metric {:label "Signups today" :delay 30000 :klass "gray big"})
(add-metric {:label "Signups today" :delay 30000 :klass "gray big"})Copyright (C) 2011 Chris Granger
Distributed under the Eclipse Public License, the same as Clojure.