Coursera Rails Module 3 Notes

I just finished the final module of this course. Overall I think it was a great course that provided a good overview of Ruby, and a thorough introduction to Rails. The next course dives into working with Databases and I am looking forward to learning more about Active Record.

Some Interesting Facts

  • Rails has only been around since 2004.
  • Startups love Rails since it makes it easy to do rapid prototyping.
  • MVC has been around since 1979

Useful Resources

The lectures had a bunch of useful tools sprinkled throughout.

Things I love about Rails

  • Convention over Configuration. I love this, I love best practices, and I love having some guidelines to follow. Think less, do more.
  • ORM makes it easy to swap out your DB as times goes on. Start dev in SQLite and should be able to seamlessly transition to MySQL, PostgreSQL, etc.
  • Rake = Ruby Make, comes with a ton of useful built in utilities. For instance if you want to see all of the routes that your application is aware of you can run rake routes.
  • Helpers (or view helpers) are reusable macros that can be used across any of your views. This is much cleaner approach than themacros that I am used to working with in Flask. There are at on of useful helpers built into rails, like “cycle” which makes it super easy to make striped HTML tables.

Things I learned

General Rails Tooling

  • Finally have a solid understanding of how Gems, Bundler, and Rbenv work together.
  • Learned about and used the HTTParty Gem
  • You can use a Pessimistic Version Constraint (Love the name) in your Gemfile which basically says do not go over a certain version. Essentially you are betting against the house and saying that you believe that an update to one of your gems is going to break everything sometime in the future. (Trust me this happens all of the time).

Testing with Rspec and Capybara

Once again, I cannot say how happy I am that this course dives right into all sorts of testing. Kudos to the JHU team for thinking about this important skill even in an introductory course. This module talked about doing acceptance testing with Capybara. We learned about:


The built in debugging tools in development mode in rails are just awesome. You get an IRB console inside of the browser, this is super useful for debugging purposes. The gems that are responsible for this functionality are byebug and web-console.

Deploying To Heroku

The course walked us through how to deploy an app to Heroku. Super simple of course. It is really nice to be able to see your application out in the wild!

Pro Tip

The rails generator makes it super easy to create all of the files that you may need for a controller or model. However if you accidentally create a model with the wrong name and your project it huge it can be somewhat daunting to figure out what is safe to remove. You can reverse a rails generated command with:

rails d $TYPE $NAME

So for example, if I created a model called recipeee

rails g model recipeee

I could remove it with

rails d model recipeee

I can see how this will come in handy in the future.

Final Project

The final project is a simple web application called Recipe Finder that allows you to search for recipes using the food2fork api. I cleaned it up a bit and added an actual search bar (the assignment just had you add query params).

This entry was posted in programming. Bookmark the permalink.

Leave a Reply

Your email address will not be published. Required fields are marked *