Rails: Building a RoR 5 API-only app
Rails 5 is finally out and API-only apps appear to now be first class citizens. I'm also excited to see Rails remain relevant in a world of single-page apps (through Turbolinks) and real-time protocols (through Actioncable).
Why Rails for API Development?
Many people will argue that Rails is too big of a framework for a simple API but oftentimes, a simple API ends up requiring different dev environments, simplified routing, CRUD generation, authentication, etc. so you're back to square one. The bottom line here is pretty simple, if you know Rails, then rest assured that many hardworking people took it upon themselves to keep your workflow running smoothly.
As for me, there are times when I use rails and times when I prefer NodeJS. The deciding factor for me is ultimately maintenance. If I can't maintain this app, who will and what is their skill set?
Rails 5 requires Ruby 2.2.2 (or above) but I prefer 2.3.1 because there are improvements with performance and memory management. Also, Heroku supports 2.3.1 so and I often try to keep up with the times.
I also suggest installing JSON Formatter for Google Chrome. It will help with JSON readability.
Step 1 - Updating Ruby & Rails
Install Ruby using
rbenv install 2.3.1
Switch to Ruby 2.x.x
rbenv global 2.3.1
gem before you install rails
gem update --system
Install rails quickly by skipping the documentation
gem install rails --version 5.0 --no-ri --no-rdoc
Step 2 - Create a new app
Create a new rails api-only app with rails 5.0 and Postgres. Here is a list of available versions.
rails _5.0.0_ new my_api_app --api -d postgresql
Rails command line options
-cto skip ActionCable
-mto skip ActionMailer
-Oto skip ActiveRecord
-Tto skip Unit Testing
-dto choose a specific database
rails helpfor more commands
Then run bundle update
Create the database (and anything else you need to do).
Step 3 - Install
Even though you've told rails to configure your app for API development, you'll need to configure a few gems to get things working properly.
ACTIVE MODEL SERIALIZERS
Serialization gems are not included in the default
Gemfile, so you must first add the Active Model Serializers manually.
If you're not familiar with AMS, it's the tool used to serialize Active Model objects. This is sort of like the secret sauce to Rails API development. Through AMS, the Rails community is essentially trying to standardize JSON API responses.
Add this to
Then add this initializer by creating the file
ActiveModel::Serializer.config.adapter = :json_api
--api attribute you used above helps rails strip out all the unecessary stuff but you'll need to manually enable CORS so that your app or other server can make data requests.
gem 'rack-cors' #Enable CORS
If you're familiar with
will_paginate or some oner pagination tool,
kaminari is great for API-type pagination.
Serialization gem 'kaminari' #Pagination
Note: Cookies, sessions, and flash messages are not required for API's but you can always go back and add them to
Step 4 - Business as Usual
Everything else should pretty much work as expected. The only major changes you might notice are the lack of:
Scaffold is a great way to get started. It will help you create the necessary models and controllers as well as te serializers you'll be using in replacement of views.
# rails g scaffold [model] [controller] fname:string lname:string email:string
They're pretty much the same.
# rails g model [model_name] [attribute:type] [attr2:type] rails g model composer fname:string lname:string dob:date dod:date nationality:string birth_city:string biography:string image_uri:string
# rails g controller [controller_name] [action1] [action2] rails g controller facts age
We no longer use
rake for migrations. Instead we keep things simple by using
Rails has a few new commands including
Quickly enable or disable the cache while in development.
Initializers lists the set of initializers that are run when your apps starts.
Update command is useful if you'll pulled someone elses code into your source.
If you use Devise, you can update the gem for Rails 5 by adding this to our
gem 'devise', git: 'https://github.com/plataformatec/devise.git'
Then run this command.
bundle update devise
If you'd prefer to install
rbenv locally, check out this stackoverflow thread.
If you think you've messed up your
gem you can always uninstall your way out of the problem.
for i in 'gem list --no-versions'; do gem uninstall -aIx $i; done
If you're doing research on other frameworks that can help you built API-only apps, I suggest you look into:
- Sinatra Framework if you know Ruby and don't want to deal with the Rails community.
- ExpressJS with Passport Local API if you're a fan of building apps using a single language.
- Amazon Lambda with AWS API Gateway if you'd rather not manage a web sever.
- Python Django if you know Python or prefer elegance.