Add comments to todomvc

examples/todomvc/src/todomvc/db.cljs

@@ -1,18 +1,23 @@
 (ns todomvc.db)
 
 
-;; -- Default Value  ----------------------------------------------------------
+;; -- Default app-db Value  ---------------------------------------------------
 
-(def default-value
-  {:todos   (sorted-map)
-   :showing :all})
+(def default-value            ;; what gets put into app-db by default.
+  {:todos   (sorted-map)      ;; use the (int) :id as the key
+   :showing :all})            ;; one of :all :done :completed
 
 
 ;; -- Local Storage  ----------------------------------------------------------
 
-(def lsk "todos-key")  ;; local store key
+(def lsk "ls-key")      ;; local store key
 
-(defn ls->todos       ;; read in todos from local storage
+(defn ls->todos
+  "Read in a list of todos from local storage, and process into a
+  sorted-map, suitable for merging into app-db.
+  LocalStorage can only keep strings, so we loose keywords on the way in.
+  Here, on load, we struggle to recreate the lost keywords. But we'll stay
+  strong, and refuse to to wimp out and go with string keys"
   []
   (some->> (.getItem js/localStorage lsk)
           (js/JSON.parse) 
@@ -24,6 +29,6 @@
 
 (defn todos->ls!
   [todos]
-  (->> (clj->js (vals todos))
+  (->> (clj->js (vals todos))        ;;  Write just the todos, not the sorted-map
        (js/JSON.stringify)
        (.setItem js/localStorage lsk)))