Refactoring

src/app/core.cljs

@@ -5,7 +5,8 @@
    [app.config :as config]
    [app.views :as views]
    [app.events :as events]
-   [app.autosave :as autosave]))
+   [nenadalm.clojure-utils.re-frame.autosave :as autosave]
+   [nenadalm.clojure-utils.cljs :as cljs-utils]))
 
 (defn mount-root []
   (re-frame/clear-subscription-cache!)
@@ -25,24 +26,10 @@
   (when-not config/debug?
     (register-worker)))
 
-(defn- prevent-screen-lock []
-  (when-some [wake-lock (.-wakeLock js/navigator)]
-    (-> wake-lock
-        (.request "screen")
-        (.then (fn []
-                 (js/document.addEventListener
-                  "visibilitychange"
-                  (fn [_]
-                    (when (= "visible" (.-visibilityState js/document))
-                      (-> wake-lock
-                          (.request "screen")
-                          (.catch (fn [_] (js/alert "Cannot prevent screen from locking.")))))))))
-        (.catch (fn [_] (js/alert "Cannot prevent screen from locking."))))))
-
 (defn ^:export init []
   (dev-setup)
   (prod-setup)
-  (prevent-screen-lock)
+  (cljs-utils/prevent-screen-lock)
   (autosave/init "nenadalm.backgammon/autosave")
   (re-frame/dispatch-sync [::events/init])
   (mount-root))

src/app/events.cljs

@@ -3,19 +3,15 @@
    [clojure.edn :as edn]
    [clojure.set :as set]
    [re-frame.core :as re-frame]
-   [app.db :as db]))
+   [app.db :as db]
+   [nenadalm.clojure-utils.cljs :as cljs-utils]))
 
 (def ^:private conjv (fnil conj []))
 
 (re-frame/reg-cofx
  :app-version
  (fn [coeffects _]
-   (assoc coeffects
-          :app-version
-          (or (some-> "meta[name=app-version]"
-                      js/document.querySelector
-                      (.getAttribute "content"))
-              "unknown"))))
+   (assoc coeffects :app-version (cljs-utils/app-version))))
 
 (re-frame/reg-cofx
  :settings

src/build/hook.clj

@@ -4,7 +4,7 @@
    [build.create-manifest]
    [build.create-index]
    [build.create-worker]
-   [build.assets :as assets]))
+   [nenadalm.clojure-utils.assets :as assets]))
 
 (defn hook
   {:shadow.build/stage :flush}

src/nenadalm/clojure_utils/README.md

@@ -0,0 +1,20 @@
+# Clojure utils
+
+This repo contains various utils, guides, … on writing apps using Clojure. It’s not meant to be anything universal, just some stuff I would copy-paste among projects without it + some guides/notes on how I do some things.
+
+## App version
+
+App version should be specified using [meta element](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/meta).
+
+example
+```html
+<meta name="app-version" content="1">
+```
+
+## App state
+
+Should be fully serializable to support autosave feature (`nenadalm.clojure-utils.re-frame.autosave`). Without this feature, app state is lost when app is closed (can easilly happen accidentaly).
+
+## Cache busting
+
+Shadow cljs [build hooks](https://shadow-cljs.github.io/docs/UsersGuide.html#build-hooks) should be used to render html and other resources to make everything work smoothly. `nenadalm.clojure-utils.assets` ns helps with asset names.

src/build/assets.clj → src/nenadalm/clojure_utils/assets.clj

@@ -1,7 +1,16 @@
-(ns build.assets
+(ns nenadalm.clojure-utils.assets
   (:require
-   [clojure.java.io :as io]
-   [build.util :as u]))
+   [clojure.java.io :as io]))
+
+(defn- sha-1 [s]
+  (let [c (java.security.MessageDigest/getInstance "sha-1")]
+    (.update c (.getBytes s "utf-8"))
+    (reduce (fn [s b] (str s (format "%02x" b))) "" (.digest c))))
+
+(defn- file-hash [f]
+  (-> f
+      slurp
+      sha-1))
 
 (defn- path [s]
   (java.nio.file.Paths/get s (make-array java.lang.String 0)))
@@ -49,7 +58,7 @@
 (defn- hash-assets [{:keys [public-dir assets]}]
   (reduce
    (fn [acc [asset src]]
-     (let [hash (u/file-hash src)
+     (let [hash (file-hash src)
            asset-path (hashed-asset asset hash)
            target (str public-dir "/" asset-path)]
        (copy src target)

src/nenadalm/clojure_utils/cljs.cljs

@@ -0,0 +1,18 @@
+(ns nenadalm.clojure-utils.cljs)
+
+(defn- request-screen [wake-lock]
+  (.request wake-lock "screen"))
+
+(defn prevent-screen-lock []
+  (when-some [wake-lock (.-wakeLock js/navigator)]
+    (-> (request-screen wake-lock)
+        (.then (fn []
+                 (js/document.addEventListener
+                  "visibilitychange"
+                  (fn [_]
+                    (when (= "visible" (.-visibilityState js/document))
+                      (request-screen wake-lock)))))))))
+
+(defn app-version []
+  (some-> (js/document.querySelector "meta[name=app-version]")
+          (.getAttribute "content")))

src/nenadalm/clojure_utils/re_frame/autosave.cljs

@@ -0,0 +1,34 @@
+(ns nenadalm.clojure-utils.re-frame.autosave
+  (:require
+   [re-frame.core :as re-frame]
+   [clojure.edn :as edn]
+   [nenadalm.clojure-utils.re-frame.local-storage :as ls]))
+
+(defn init [autosave-key]
+  (re-frame/reg-event-fx
+   ::autosave
+   (fn [{:keys [db]}]
+     {::ls/set {autosave-key (pr-str db)}}))
+
+  (re-frame/reg-event-fx
+   ::autosave-remove
+   (fn [_]
+     {::ls/remove [autosave-key]}))
+
+  (re-frame/reg-event-fx
+   ::autosave-load
+   [(re-frame/inject-cofx ::ls/get {:autosave-str autosave-key})]
+   (fn [cofx]
+     (if-let [autosave (edn/read-string (:autosave-str cofx))]
+       {:db autosave
+        ::ls/remove [autosave-key]}
+       {})))
+
+  (re-frame/dispatch [::autosave-load])
+  (js/document.addEventListener
+   "visibilitychange"
+   (fn []
+     (case (.-visibilityState js/document)
+       "visible" (re-frame/dispatch [::autosave-remove])
+       "hidden" (re-frame/dispatch [::autosave])
+       nil))))

src/nenadalm/clojure_utils/re_frame/local_storage.cljs

@@ -0,0 +1,24 @@
+(ns nenadalm.clojure-utils.re-frame.local-storage
+  (:require
+   [re-frame.core :as re-frame]))
+
+(re-frame/reg-fx
+ ::set
+ (fn [kv]
+   (doseq [[k v] kv]
+     (js/window.localStorage.setItem k v))))
+
+(re-frame/reg-cofx
+ ::get
+ (fn [coeffects kv]
+   (reduce-kv
+    (fn [m k v]
+      (assoc m k (js/window.localStorage.getItem v)))
+    coeffects
+    kv)))
+
+(re-frame/reg-fx
+ ::remove
+ (fn [ks]
+   (doseq [k ks]
+     (js/window.localStorage.removeItem k))))