Hi, i think you don't need the fn partt here

(defn x-chart []
  (let [chart-labels (rf/subscribe [:x/x-labels])
        chart-data (rf/subscribe [:x/x-data])]
    (fn []
      [gen-x-chart @chart-labels @chart-data])
    ))

(defn x-chart []
  (let [chart-labels (rf/subscribe [:x/x-labels])
        chart-data (rf/subscribe [:x/x-data])]
      [gen-x-chart @chart-labels @chart-data]
    ))

also component-did-mount does not receive the same arguments. It receive props

i'll try to make an exmaple

defn chart
  [data]
  (r/create-class
   {:component-did-mount
    (fn [this]
      (println (r/props this)))
    :component-did-update
    (fn [this]
      (println "updated-data" (r/props this)))
    :reagent-render
    (fn [data]
      [:div (:label data) (:data data)])}))

[chart {:label "label" :data [0 1 2]]

hope this help

@U0F7M1KA7 thank you so much, i'll try that now