core.cljs

(ns react-cljs.core
  (:require-macros [reactjs.macros :refer [pure]])
  (:require React [reactjs.core :as r]))

(enable-console-print!)

(declare render-ui)

(defn render-counter [id state cb]
  (pure state
    (React/DOM.div nil
      (React/DOM.label nil (:count state))
      (React/DOM.button
        (js-obj "onClick" #(cb (update-in state [:count] inc)))
        "+")
      (React/DOM.button
        (js-obj "onClick" #(cb (update-in state [:count] dec)))
        "-"))))

(defn render-ui [n]
  (let [state (atom (zipmap (range n) (repeat {:count 0})))]
    ((fn loop []
       (let [state' @state]
         (React/renderComponent
           (pure state'
             (React/DOM.div nil
               (into-array
                 (concat
                   [(React/DOM.h1 nil "A Counting Widget!")]
                   (map (fn [n]
                          (render-counter n (get state' n)
                            #(do (swap! state assoc n %) (loop))))
                     (range n))))))
           js/document.body))))))

(render-ui 10)

macros.clj

(ns reactjs.macros)

(defmacro pure [value children]
  `(reactjs.core/Pure. (cljs.core/js-obj "value" ~value) (fn [] ~children)))

pure.cljs

(ns reactjs.core
  (:require React))

(def Pure
  (React/createClass
    (js-obj
      "shouldComponentUpdate"
      (fn [next-props next-state]
        (this-as this
          (not (= (.. this -props -value) (.-value next-props)))))
      "render"
      (fn []
        (this-as this
          ((.. this -props -children)))))))

This plus the hiccup style templating I borrowed from pump is turning in to a knockout punch.

I'm still evaluating these macros but so far it's been very nice.

(defmacro deftemplate [name bindings & body]
  `(defn ~name ~bindings
     (react/html ~@body)))

(defmacro defhtmlcomponent [name bindings & body]
  (let [data-sym (first bindings)]
    `(defn ~name ~bindings
       (pure ~data-sym (react/html ~@body)))))

Here's a basic example of how it looks in action.

(deftemplate link-to [href & content]
  [:a {:href href} content])

(defhtmlcomponent SiteNavigation [links]
  [:div {:id "site-navigation"}
   [:ul 
    (for [link links]
      [:li
       (link-to (:href link) (:description link))])]])

(react/render-component
 (SiteNavigation [{:href "/home" :description "Home"}
                  {:href "/about" :description "About us"}
                  {:href "/contact" :description "Contact us"}])
 site-navigation-mount-point)