Implement layout and device list page

client/app.js

@@ -1,5 +1,43 @@
 "use strict";
 
-const m = require("mithril");
+import m from "mithril";
 
-m.render(document.body, "hello world");
+import layout from "./layout";
+import * as overviewPage from "./overview-page";
+import * as devicesPage from "./devices-page";
+import * as errorPage from "./error-page";
+
+let state;
+
+function pagify(pageName, page) {
+  const component = {
+    render: () => {
+      if (state && state.error) return m(errorPage.component, state);
+      else return m(layout, { page: pageName }, m(page.component, state));
+    }
+  };
+
+  if (page.init)
+    component.onmatch = args => {
+      return new Promise(resolve => {
+        page
+          .init(args)
+          .then(st => {
+            if (!st) return m.reoute.set("/");
+            state = st;
+            resolve();
+          })
+          .catch(err => {
+            state = { error: err.message };
+            resolve();
+          });
+      });
+    };
+
+  return component;
+}
+
+m.route(document.body, "/overview", {
+  "/overview": pagify("overview", overviewPage),
+  "/devices": pagify("devices", devicesPage)
+});