You need to have a place where you can do your work this term.There are a few options available to you. You only need to do the one that works best for your situation. If you want the simplest setup, then just use Cloud 9 from Amazon Web Services, but then you need a credit card to sign up. If you want more control, and to work locally, then install to your OS.

All of the coursework is set up to use Rails 6.0.3.1 using Ruby 2.6.3 – use a combo similar to this

Git is also needed for working with Ruby and Rails

Git is used for version control, and lets you deploy your applications onto Heroku. Follow the instruction here for your platform.

Be sure to also set up you ssh keys too, as you’ll need these later. You can find more about using Git at https://git-scm.com/book/en/v2, and you can also read the details of deploying to Heroku with Git.

Testing Your Rails Solution by building a bigger app and deploying it to Heroku

To ensure that all of this works correctly we should now create a simple app. We’ll do this by creating a boat yard, or marina of boats.

Open a terminal and cd to where you want to keep all of your Rails applications. I keep mine under a folder called ‘RailsApps’ so they’re all in one place.

Move into this space in a terminal, and then enter the command:

This will generate a new directory with many files in it.

Move into the new ‘boatyard’ folder with your terminal. We have lots of folders and files here that will help us keep our application development organised so that it’s easier to maintain.

Next we want to create some boats using the built in scaffolding of Rails. We can use one command to build a boat model, connect it to a controller, and associate it those with a view to display on the page as well. Type out the following into your terminal:

This will again generate more files for you, which you should see as being part of the boat objects.

The next step is to tell the app about the new database information for our boatyard objects with the command

This should create the ‘boats’ table.

We can now start the server and see our work with the command

This should tell you that Puma is starting in single mode and is listening on tcp://0.0.0.0:3000

Open your browser and go to http://localhost:3000. Hang on, that’s not your app is it? All those happy people around the globe? This is the ‘standard’ welcome page to show your app is ready and running. We haven’t created a ‘home’ page for the app.We have only created a page for the boats. To see the ‘boats’you need to go to http://localhost:3000/boats where you can add a ‘new boat’. Fill in the form and create a boat. See what happens if you create a boat without filling in any details.

This should all work. It’s not pretty, but it works and helps you quickly create a website. You can shut down the server with the command ‘ctrl-c’ which you do by pressing down both the’control’, or ‘ctrl’ key and the ‘c’ key at the same time.

Pushing your boatyard to Heroku

In order to push our application to Heroku, we need to put it into a Git repository. Heroku only accepts applications as Git repos. For now just follow the commands to ensure that you have everything set up correctly. We’ll go over details in a later session.

We also need to change our Gemfile before we can push the application to Heroku because it uses Postgreql instead ofSqlite3 for the database.Your gemfile details the gems used in your application, and as we want to use Postgresql for production, we need to include that in the file. Open boatyard/gemfile and add these lines:

group :development, :test do
 gem 'sqlite3'
 gem 'byebug', platform: :mri
end

group :production do
 gem 'pg'
end

Also comment out any reference to sqlite3 in the main body of the Gemfile. Then copy that and move it to the ‘development and test’ sections next to ‘byebug’ gem,  then save the file.

Step 4) You need to run bundle install to add the gem. This might take a while.

bundle install

Given you’re still in the boats directory  use

git init
git add .
git commit -m ‘my first commit’

This should set up your repo, fill it, and then commit the code to it, and show your local git repository working fine.

Sign up for an account at http://heroku.com and then follow the instructions at https://devcenter.heroku.com/articles/getting-started-with-ruby#set-up. If you’re on the WAD-2019 image in VirtualBox, then you have heroku installed. If you’re on cloud 9, and heroku isn’t already installed, then use the ‘other installation methods’ for installing the CLI. The CLI install instructions work better than the one’s for Snap.

If you don’t have an ssh key in your .ssh directory, (which you probably don’t), then you will need to create one using the details at github. This is an extra layer of security over and above your username/password combo.

Upload the ssh key you created for use with Git when prompted.NOTE: when uploading your ssh key supply your heroku password when prompted for a password.

You may need to supply your public ssh key manually in order for this to work. Your ssh keys will be under <youraccount>./ssh then you need to use this command inside a Git bash shell after you’ve used to cd to get to the .ssh directory:

heroku keys:add id_rsa.pub

It will ask for your email and Heroku password and then upload the file.

You can now create your app on the heroku server and then upload your app. Be patient during this phase as you are working remotely so give the servers time to respond to your commands.

Use the ‘heroku create’ command inside the boatyard directory to create your app on the server and get its default name. You should see that heroku adds a remote repository to your git repository for remote deployment and tells you what the URL will be.

If the heroku create command doesn’t add your remote repository details, then you can run the command yourself with

git remote add herokugit@heroku.com:your-app-name.git

you can now push the app to heroku with

git push heroku master

Do this now and you’ll see a quick message about adding an RSAhost for an IP address …. and then details about writing your objects to the repository and then it will configure the gems it needs to run your Rails application. This may take a bit of time, so be patient. When it is done it will launch your application and tell you the URL it’s it running at.

If you go to the URL, you’ll see the ‘We’re sorry, but something went wrong message’ as you’ve not configured the database yet.

We need to tell heroku to create our tables by using these commands:

heroku rake db:create
heroku rake db:migrate

You will probably have a message that some weird database name already exists after the first command, and the second command should show your tables being created. If you now reload the page where your app is, then it should appear there correctly.

Extending the practical

If you still have time, then you can also explore these other changes with the boatyard to become more familiar with Rails.We’ll cover this later too, of course. The main documentation for modifying views is found in ‘Layouts and Rendering Guide‘ for Rails.

The main folder to explore is the ‘boatyard/app’ directory,which is where you’ll find the ‘views’ folder, which holds your’boats’ and ‘layouts’ views.

The ‘layouts/application.html.erb’ file is applied to all viewsin the browser so changes here impact the whole site. You might want to show the name of the whole site across all pages.

The ‘boats’ folder holds the ‘index.html.erb’ file, which is what’s shown when you see the list of all boats. It also holds the show.html.erb file, which is used to display a single boat.You could change how boats are displayed, and maybe add more detail of how single boats are displayed.