mzemel

cd ~/jeopardy                       # change to application directory (run all commands in this directory)
bundle exec rails server -b 0.0.0.0 # start application (available on host machine at localhost:3000)
git pull origin master              # get latest code
bundle exec rails db:migrate         # apply database migrations
bundle install                      # install any missing dependencies
bundle exec rails assets:precompile  # build .css files
bin/webpack                         # build .js files
bundle exec rails console           # start rails console
sqlite3 db/development.sqlite3      # start SQL console
  > .headers on                       # add headers

mzemel

#!/usr/bin/env ruby

A = <<-A
 +
+ +
+++
+ +
+ +
A

mzemel

Rails, React, and ActiveModelSerializers

Creating a modular component for React and Rails

Problem: We have several RESTful resources that could use just single, generic React component to display them. To populate a table dynamically, we need to give some meta-data to the React component. This will take the form of a reusable Ruby JSON-serializer.

React side

React is rendered in Rails

Feel free to skip this, as it's more background.

mzemel

# app/views/projects/index.html.erb

<p id="notice"><%= notice %></p>

<%= react_component "ProjectList", url: "/projects", pollInterval: 5000, data: @projects.to_json %>

mzemel

defmodule SweetSpot do
  defmacro if(predicate, do: expression) do
  end
end

defmodule Test do
  require SweetSpot

  SweetSpot.if(true, do: IO.puts "Hello world")
  

mzemel

defmodule Calculator do
  use Application

  # See http://elixir-lang.org/docs/stable/elixir/Application.html
  # for more information on OTP Applications
  def start(_type, initial_value) do
    import Supervisor.Spec, warn: false

    children = [
      # Define workers and child supervisors to be supervised

mzemel

defmodule Calculator.Mixfile do
  use Mix.Project

  def project do
    [app: :calculator,
     version: "0.0.1",
     elixir: "~> 1.0",
     build_embedded: Mix.env == :prod,
     start_permanent: Mix.env == :prod,
     deps: deps]

mzemel

defmodule Calculator do
  use GenServer

  ###
  # External API

  def start_link(initial \\ 0) do
    GenServer.start_link(__MODULE__, initial, name: __MODULE__)
  end

mzemel

defmodule MyServer do
  use GenServer

  def handle_call({:plus, number}, _from, current_number) do
    new_number = current_number + new_value
    {:reply, new_number, new_number}
  end

end

mzemel

defmodule Greeter do
  def greet do
    receive do
      {sender, msg} -> 
        send sender, {:ok, "Hello #{msg}"}
        greet
    end
  end
end