Toggle chart series in clojurescript

Question

I'm toggling on/off series in chart and was wondering if I was doing anything crazy.

Is the atom really a good idea here?

;; ================ Graph data ================
(def serie1 {:label "Bar" :data [[11 13] [19 11] [30 -7]]})
(def serie2 {:label "Foo" :data [[10 1] [17 -14] [30 5]]})
(def serie3 {:label "Zon" :data [[8 2] [18 7] [30 15]]})
(def series (for [serie [serie1 serie2 serie3]]
 {:label (:label serie) :action "toggle-serie" :param serie}))
;; ============ Chart state ================
(def !chart
 "Chart state"
 (atom []))
(defn toggle-serie! [serie]
 "Return the series collection minus/plus the given serie"
 (swap! !chart #(if (some #{serie} %)
 (remove #{serie} %)
 (conj % serie))))
(defn reset-chart []
 "Reset chart state"
 (reset! !chart []))
;;================ Page population ================
; almost identical to ibdknox overtone example
(defpartial button [{:keys [label action param]}]
 [:a.button {:href "#" :data-action action :data-param param} label])
(defn populate [container buttons]
 (doseq [b buttons]
 (append container (button b))))
(populate ($ :#series) series)
;; ================ Button functions ================
(defn plot
 "Plot the given series and return the chart as an object."
 [placeholder coll-data & options]
 (js/jQuery.plot placeholder (clj->js coll-data) (clj->js options)))
(def chart ($ :#chart))
(defn toggle-serie-and-update-chart!
 "Add or remove a serie form the chart atom and redraw the chart."
 [serie]
 (toggle-serie! serie) ;update the chart atom
 (plot chart @!chart)) ; redraw the chart
(delegate ($ :#series) button :click
 (fn [e]
 (.preventDefault e)
 (this-as me 
 (let [$me ($ me)
 param (cljs.reader/read-string (data $me :param))]
 (toggle-serie-and-update-chart! param)))))

Answer 1

If your dataset were coming from an outside source, like an API call, I'd say the atom would make sense. In this case, your dataset is static. In that case, I think I might find it more intuitive to use a var for the series and then select the items out that you want to plot. In that case, your state is really just a list of which series (you are selecting).

So, if you had all your series:

(def all-series
 {:series1 :...series1
 :series2 :...series2
 :series3 :...series3})

!chart might contain #{:series1 :series3} and you could get all the values out using (select-keys all-series @!chart).

You might find you can avoid the atom altogether, but at the very least I'd always look for ways to keep that state as simple as