MVP version. Added actioncables for counting.

app/channels/count_channel.rb

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+class CountChannel < ApplicationCable::Channel
+  def subscribed
+    # TODO: check to make sure this is unique.
+    stream_from 'chat'
+  end
+
+  def increment(_payload = 1)
+    cluster = Cluster.list.values.first
+    cluster.increment
+    ActionCable.server.broadcast 'chat', message: render(cluster)
+  end
+
+  def decrement(_payload = 1)
+    cluster = Cluster.list.values.first
+    cluster.decrement
+    ActionCable.server.broadcast 'chat', message: render(cluster)
+  end
+
+  private
+
+  def render(cluster)
+    ApplicationController.new.helpers.c('counter-count', cluster: cluster)
+  end
+end

app/controllers/cluster_controller.rb

@@ -9,7 +9,7 @@ class ClusterController < ApplicationController
 
   def create
     cluster = Cluster.new(params[:cluster])
-    session[:cluster_uuid] = cluster.uuid;
+    session[:cluster_uuid] = cluster.uuid
     redirect_to root_path
   end
 

app/controllers/counter_controller.rb

@@ -3,7 +3,9 @@
 class CounterController < ApplicationController
   before_action :associate!
 
-  def show; end
+  def show
+    @cluster = Cluster.get(session[:cluster_uuid])
+  end
 
   private
 

app/views/counter/show.html.erb

@@ -1,13 +1,3 @@
-  <section class="section">
-    <div class="container">
-      <h1 class="title">
-        Hello World
-      </h1>
-      <p class="subtitle">
-         <span class="icon">
-             <i class="fas fa-home"></i>
-         </span>
-        My first website with <strong>Bulma</strong>!
-      </p>
-    </div>
-  </section>
+<%= c("page") do %>
+    <%= c("counter-view") %>
+<% end %>

frontend/client/cable.js

@@ -0,0 +1,13 @@
+import cable from "actioncable";
+
+let consumer;
+
+const createChannel = (...args) => {
+  if (!consumer) {
+    consumer = cable.createConsumer();
+  }
+
+  return consumer.subscriptions.create(...args);
+};
+
+export default createChannel;

frontend/client/counter.js

@@ -0,0 +1,20 @@
+import createChannel from "client/cable";
+
+let callback; // declaring a variable that will hold a function later
+
+const chat2 = createChannel("CountChannel", {
+  received({ message }) {
+    if (callback) callback.call(null, message);
+  },
+});
+
+const sendIncrement = (message) => chat2.perform("increment", { message });
+const sendDecrement = (message) => chat2.perform("decrement", { message });
+
+// Getting a message: this callback will be invoked once we receive
+// something over ChatChannel
+const setCallback = (fn) => {
+  callback = fn;
+};
+
+export { sendIncrement, sendDecrement, setCallback };

frontend/components/cluster-new/cluster-new.pcss

@@ -33,3 +33,5 @@
     }
   }
 }
+
+/*  -*- mode: css;  -*- */

frontend/components/counter-count/_counter-count.html.erb

@@ -0,0 +1 @@
+<%= cluster.count %>

frontend/components/counter-count/counter-count.js

@@ -0,0 +1,12 @@
+import "./counter-count.pcss";
+
+import { setCallback } from "client/counter";
+
+window.addEventListener("DOMContentLoaded", () => {
+  const currentCount = document.querySelector(".count");
+  if (currentCount) {
+    setCallback((message) => {
+      currentCount.innerHTML = message;
+    });
+  }
+});

frontend/components/counter-count/counter-count.pcss

@@ -0,0 +1 @@
+/* placeholder */

frontend/components/counter-down-btn/_counter-down-btn.html.erb

@@ -0,0 +1,3 @@
+<a class="counter-down-btn">
+    <i class="fas fa-angle-double-down"></i>
+</a>

frontend/components/counter-down-btn/counter-down-btn.js

@@ -0,0 +1,13 @@
+import "./counter-down-btn.pcss";
+
+import { sendDecrement } from "client/counter";
+
+window.addEventListener("DOMContentLoaded", () => {
+  const btn = document.querySelector(".counter-down-btn");
+  if (btn) {
+    btn.addEventListener("click", (event) => {
+      event.preventDefault();
+      sendDecrement(1);
+    });
+  }
+});

frontend/components/counter-down-btn/counter-down-btn.pcss

@@ -0,0 +1 @@
+/* placeholder */

frontend/components/counter-up-btn/_counter-up-btn.html.erb

@@ -0,0 +1,3 @@
+<a class="counter-up-btn">
+    <i class="fas fa-angle-double-up"></i>
+</a>

frontend/components/counter-up-btn/counter-up-btn.js

@@ -0,0 +1,13 @@
+import "./counter-up-btn.pcss";
+
+import { sendIncrement } from "client/counter";
+
+window.addEventListener("DOMContentLoaded", () => {
+  const btn = document.querySelector(".counter-up-btn");
+  if (btn) {
+    btn.addEventListener("click", (event) => {
+      event.preventDefault();
+      sendIncrement(-1);
+    });
+  }
+});

frontend/components/counter-up-btn/counter-up-btn.pcss

@@ -0,0 +1 @@
+/* placeholder */

frontend/components/counter-view/_counter-view.html.erb

@@ -0,0 +1,11 @@
+<div class="counter-view">
+    <div class="row">
+    <%= c("counter-up-btn") %>
+    </div>
+    <div class="row count">
+        <%= c("counter-count", cluster: @cluster) %>
+    </div>
+    <div class="row">
+    <%= c("counter-down-btn") %>
+    </div>
+</div>

frontend/components/counter-view/counter-view.js

@@ -0,0 +1,5 @@
+import "./counter-view.pcss";
+
+import "components/counter-up-btn/counter-up-btn";
+import "components/counter-count/counter-count";
+import "components/counter-down-btn/counter-down-btn";

frontend/components/counter-view/counter-view.pcss

@@ -0,0 +1,16 @@
+.counter-view {
+  display: flex;
+  flex-direction: column;
+  justify-content: center;
+  align-items: center;
+  width: 100%;
+  height: 100%;
+
+  & .row {
+    display: flex;
+    height: 33%;
+    justify-content: center;
+    align-items: center;
+    font-size: 4rem;
+  }
+}

frontend/components/page/page.pcss

@@ -1,6 +1,6 @@
 .page {
   height: 100vh;
-  width: 700px;
   margin: 0 auto;
+  max-width: 700px;
   overflow: hidden;
 }

frontend/packs/application.js

@@ -2,3 +2,4 @@ import "init";
 
 import "components/page/page";
 import "components/cluster-view/cluster-view";
+import "components/counter-view/counter-view";

package.json

@@ -6,6 +6,7 @@
     "@rails/actioncable": "^6.0.0",
     "@rails/ujs": "^6.0.0",
     "@rails/webpacker": "4.2.2",
+    "actioncable": "^5.2.4-3",
     "bulma": "^0.8.2",
     "normalize.css": "^8.0.1",
     "postcss-flexbugs-fixes": "^4.2.1",

test/channels/count_channel_test.rb

@@ -0,0 +1,10 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class CountChannelTest < ActionCable::Channel::TestCase
+  # test "subscribes" do
+  #   subscribe
+  #   assert subscription.confirmed?
+  # end
+end

yarn.lock

@@ -1115,6 +1115,11 @@ acorn@^7.1.1:
   resolved "https://registry.yarnpkg.com/acorn/-/acorn-7.2.0.tgz#17ea7e40d7c8640ff54a694c889c26f31704effe"
   integrity sha512-apwXVmYVpQ34m/i71vrApRrRKCWQnZZF1+npOD0WV5xZFfwWOmKGQ2RWlfdy9vWITsenisM8M0Qeq8agcFHNiQ==
 
+actioncable@^5.2.4-3:
+  version "5.2.4-3"
+  resolved "https://registry.yarnpkg.com/actioncable/-/actioncable-5.2.4-3.tgz#cb4d1f4a6a8164ac9abe623eca2c382fe05e7d47"
+  integrity sha512-SrGfg2W2GKGfYOlsOUnqjdihUhIVoyb5ewsMtpfE/Z3ZK/j5Gj2e/YWp2A7Wo+aeB1aewhPxorFxIGVRowbX4w==
+
 aggregate-error@^3.0.0:
   version "3.0.1"
   resolved "https://registry.yarnpkg.com/aggregate-error/-/aggregate-error-3.0.1.tgz#db2fe7246e536f40d9b5442a39e117d7dd6a24e0"