Start experimenting with batched rendering with requestAnimationFrame

demo/reagentdemo/common.cljs

@@ -39,7 +39,8 @@
          [:div.demo-example
           [:a.demo-example-hide {:on-click (fn [e]
                                              (.preventDefault e)
-                                             (swap! showing not))}
+                                             (swap! showing not)
+                                             false)}
            (if @showing "hide" "show")]
           [:h3.demo-heading "Example "]
           (when @showing

project.clj

@@ -1,5 +1,5 @@
 
-(defproject reagent "0.2.1"
+(defproject reagent "0.3.0-SNAPSHOT"
   :url "http://github.com/holmsand/reagent"
   :license {:name "MIT"}
   :description "A simple ClojureScript interface to React"

src/reagent/core.cljs

@@ -1,6 +1,6 @@
 
 (ns reagent.core
-  (:refer-clojure :exclude [partial atom])
+  (:refer-clojure :exclude [partial atom flush])
   (:require-macros [reagent.debug :refer [dbg prn]])
   (:require [reagent.impl.template :as tmpl]
             [reagent.impl.component :as comp]
@@ -105,6 +105,10 @@ specially, like React's transferPropsTo."
   [defaults props]
   (util/merge-props defaults props))
 
+(defn flush []
+  (comp/flush))
+
+
 
 ;; Ratom
 

src/reagent/impl/component.cljs

@@ -1,5 +1,6 @@
 
 (ns reagent.impl.component
+  (:refer-clojure :exclude [flush])
   (:require [reagent.impl.template :as tmpl
              :refer [cljs-props cljs-children React]]
             [reagent.impl.util :as util]
@@ -43,10 +44,46 @@
 (defn set-props [C newprops]
   (replace-props C (merge (get-props C) newprops)))
 
+;;; Rendering
 
-;;; Function wrapping
+(defn next-tick [f]
+  (if (.-requestAnimationFrame js/window)
+    (js/requestAnimationFrame f)
+    (js/setTimeout f 16)))
+
+(defn run-queue [v]
+  (doseq [C v]
+    (when-not (.-cljsIsDirty C)
+      (dbg C))
+    (when (.-cljsIsDirty C)
+      (.forceUpdate C))))
+
+(deftype RenderQueue [^:mutable queue ^:mutable scheduled?]
+  Object
+  (queue-render [this C]
+    (set! queue (conj queue C))
+    (.schedule this))
+  (schedule [this]
+    (when-not scheduled?
+      (set! scheduled? true)
+      (next-tick #(.run-queue this))))
+  (run-queue [_]
+    (let [q queue]
+      (set! queue (empty queue))
+      (set! scheduled? false)
+      (run-queue q))))
+
+(def render-queue (RenderQueue. [] false))
+
+(defn flush []
+  (.run-queue render-queue))
+
+(defn queue-render [C]
+  (set! (.-cljsIsDirty C) true)
+  (.queue-render render-queue C))
 
 (defn do-render [C f]
+  (set! (.-cljsIsDirty C) false)
   (let [p (js-props C)
         props (props-in-props p)
         children (aget p cljs-children)
@@ -66,10 +103,13 @@
           (ratom/make-reaction
            #(do-render C (.-cljsRenderFn C))
            :auto-run (if tmpl/isClient
-                                #(.forceUpdate C)
+                       #(queue-render C)
-                                identity))))
+                       identity))))
   (ratom/run (.-cljsRatom C)))
 
+
+;;; Function wrapping
+
 (defn custom-wrapper [key f]
   (case key
     :getDefaultProps
@@ -108,6 +148,7 @@
     :componentWillUnmount
     (fn [C]
       (ratom/dispose! (.-cljsRatom C))
+      (set! (.-cljsIsDirty C) false)
       (when f (f C)))
 
     :render

test/testcloact.cljs

@@ -95,27 +95,34 @@
     (let [ran (atom 0)
           runs (running)
           val (atom 0)
+          secval (atom 0)
           v1 (reaction @val)
           comp (fn []
                  (swap! ran inc)
-                 [:div (str "val " @v1)])]
+                 [:div (str "val " @v1 @val @secval)])]
       (with-mounted-component [comp]
         (fn [C div]
-          (swap! ran inc)
+          (reagent/flush)
           (is (not= runs (running)))
           (is (found-in #"val 0" div))
-          (is (= 2 @ran))
+          (is (= 1 @ran))
 
+          (reset! secval 1)
+          (reset! secval 0)
           (reset! val 1)
+          (reset! val 2)
+          (reset! val 1)
+          (reagent/flush)
           (is (found-in #"val 1" div))
-          (is (= 3 @ran))
+          (is (= 2 @ran))
 
           ;; should not be rendered
           (reset! val 1)
+          (reagent/flush)
           (is (found-in #"val 1" div))
-          (is (= 3 @ran))))
+          (is (= 2 @ran))))
       (is (= runs (running)))
-      (is (= 3 @ran)))))
+      (is (= 2 @ran)))))
 
 (deftest init-state-test
   (when isClient