Add function to insert a new article.

src/main/blog/db.cljs

@@ -45,3 +45,18 @@
       (catch js/Error err (js/console.log (ex-cause err)))))
   channel)
 
+(defn insert-article
+  "Insert an article and return the id via channel. It gets and returns the same channel."
+  [client title content channel]
+  (go
+    (try
+      (let [res (<p! (.query client
+                             "insert into articles(title, content) values($1, $2) returning id;"
+                             (clj->js [title content])))]
+        (>! channel (-> (.-rows res)
+                        (js->clj :keywordize-keys true)
+                        (first)
+                        (:id))))
+      (catch js/Error err (js/console.log (ex-cause err)))))
+  channel)
+