From c90c5e41d29f539e791b4066e0146ec554e95981 Mon Sep 17 00:00:00 2001
From: Nicholas Kariniemi <nicholas.kariniemi@gmail.com>
Date: Thu, 7 Aug 2014 23:40:48 +0300
Subject: [PATCH] Fix bug with unmounted items crashing it

Close core.async channels on unmount, check for unmounted before calling
	get-node in listeners
---
 src/cljs/grub/view/grub.cljs        | 31 +++++++++++++++++++----------
 src/cljs/grub/view/recipe.cljs      | 24 ++++++++++++++++------
 src/cljs/grub/view/recipe_list.cljs | 20 +++++++++++++++----
 3 files changed, 55 insertions(+), 20 deletions(-)

diff --git a/src/cljs/grub/view/grub.cljs b/src/cljs/grub/view/grub.cljs
index 1bdf7c4..0c22a03 100644
--- a/src/cljs/grub/view/grub.cljs
+++ b/src/cljs/grub/view/grub.cljs
@@ -63,7 +63,8 @@
     (init-state [_]
       (let [publisher (chan)]
         {:edit-state :waiting
-         :grub grub}))
+         :grub grub
+         :unmounted false}))
 
     om/IRenderState
     (render-state [_ {:keys [edit-state] :as state}]
@@ -87,17 +88,27 @@
           :on-change #(om/set-state! owner :grub (.. % -target -value))
           :on-key-up #(when (dom/enter-pressed? %) (transition-state owner :enter))}]]))
 
-    om/IWillMount
-    (will-mount [_]
+    om/IDidMount
+    (did-mount [_]
       (let [<events (om/get-shared owner :<events)
             subscriber (chan)]
+        (om/set-state! owner :subscriber subscriber)
         (a/sub <events :body-mousedown subscriber)
         (a/sub <events :body-scroll subscriber)
         (go-loop [] (let [event (<! subscriber)]
-                      (when (and (= (:type event) :body-mousedown)
-                                 (not (dom/click-on-self? (:event event) 
-                                                          (om/get-node owner))))
-                        (transition-state owner :body-mousedown))
-                      (when (= (:type event) :body-scroll)
-                        (transition-state owner :scroll))
-                      (recur)))))))
+                      (when-not (or (om/get-state owner :unmounted)
+                                    (nil? event))
+                        (when (and (= (:type event) :body-mousedown)
+                                   (not (dom/click-on-self? (:event event) 
+                                                            (om/get-node owner))))
+                          (transition-state owner :body-mousedown))
+                        (when (= (:type event) :body-scroll)
+                          (transition-state owner :scroll)))))))
+    om/IWillUnmount
+    (will-unmount [_]
+      (let [<events (om/get-shared owner :<events)
+            subscriber (om/get-state owner :subscriber)]
+        (om/set-state! owner :unmounted true)
+        (a/unsub <events :body-mousedown subscriber)
+        (a/unsub <events :body-scroll subscriber)
+        (a/close! (om/get-state owner :subscriber))))))
diff --git a/src/cljs/grub/view/recipe.cljs b/src/cljs/grub/view/recipe.cljs
index 71e5dd7..59e663d 100644
--- a/src/cljs/grub/view/recipe.cljs
+++ b/src/cljs/grub/view/recipe.cljs
@@ -59,7 +59,8 @@
       (let [publisher (chan)]
         {:edit-state :waiting
          :name (:name props)
-         :grubs (:grubs props)}))
+         :grubs (:grubs props)
+         :unmounted false}))
 
     om/IWillReceiveProps
     (will-receive-props [this next-props]
@@ -101,12 +102,23 @@
              :on-click #(transition-state owner :save)}
             "Save"]]])))
     
-    om/IWillMount
-    (will-mount [_]
+    om/IDidMount
+    (did-mount [_]
       (let [<events (om/get-shared owner :<events)
             subscriber (chan)]
+        (om/set-state! owner :subscriber subscriber)
         (a/sub <events :body-mousedown subscriber)
         (go-loop [] (let [event (<! subscriber)]
-                      (when-not (dom/click-on-self? (:event event) (om/get-node owner))
-                        (transition-state owner :body-mousedown))
-                      (recur)))))))
+                      (when-not (or (nil? event)
+                                    (om/get-state owner :unmounted))
+                        (when-not (dom/click-on-self? (:event event) (om/get-node owner))
+                          (transition-state owner :body-mousedown))
+                        (recur))))))
+    
+    om/IWillUnmount
+    (will-unmount [_]
+      (let [<events (om/get-shared owner :<events)
+            subscriber (om/get-state owner :subscriber)]
+        (om/set-state! owner :unmounted true)
+        (a/unsub <events :body-mousedown subscriber)
+        (a/close! (om/get-state owner :subscriber))))))
diff --git a/src/cljs/grub/view/recipe_list.cljs b/src/cljs/grub/view/recipe_list.cljs
index 31c2b6b..b16bc53 100644
--- a/src/cljs/grub/view/recipe_list.cljs
+++ b/src/cljs/grub/view/recipe_list.cljs
@@ -39,7 +39,8 @@
       (let [publisher (chan)]
         {:edit-state :waiting
          :new-recipe-name ""
-         :new-recipe-grubs ""}))
+         :new-recipe-grubs ""
+         :unmounted false}))
 
     om/IRenderState
     (render-state [this {:keys [edit-state new-recipe-name new-recipe-grubs]}]
@@ -73,10 +74,21 @@
       (let [<events (om/get-shared owner :<events)
             subscriber (chan)]
         (a/sub <events :body-mousedown subscriber)
+        (om/set-state! owner :subscriber subscriber)
         (go-loop [] (let [event (<! subscriber)]
-                      (when-not (dom/click-on-self? (:event event) (om/get-node owner))
-                        (transition-state owner :body-mousedown))
-                      (recur)))))))
+                      (when-not (or (nil? event)
+                                    (om/get-state owner :unmounted))
+                        (when-not (dom/click-on-self? (:event event) (om/get-node owner))
+                          (transition-state owner :body-mousedown))
+                        (recur))))))
+    
+    om/IWillUnmount
+    (will-unmount [_]
+      (let [<events (om/get-shared owner :<events)
+            subscriber (om/get-state owner :subscriber)]
+        (om/set-state! owner :unmounted true)
+        (a/unsub <events :body-mousedown subscriber)
+        (a/close! (om/get-state owner :subscriber))))))
 
 (defn view [recipes owner]
   (reify