CRUD JSON ActiveRecord

Important: These docs are for the outdated Jets 5 versions and below. For the latest Jets docs: docs.rubyonjets.com

The easiest way to get a CRUD JSON API ActiveRecord app running by using the jets new with --api and the scaffold generator.

Summary

Here’s a summary of the commands:

jets new demo --mode api
cd demo
jets generate scaffold post title:string
edit .env.development # adjust to your local database creds
jets db:create db:migrate
jets server # Check out site at http://localhost:8888/posts

Let’s go through each in a little more detail.

Generate a new project

$ jets new demo --mode api
Creating a new Jets project called demo.
      create  demo/app/controllers/application_controller.rb
      create  demo/app/helpers/application_helper.rb
      create  demo/app/jobs/application_job.rb
...
================================================================
Congrats  You have successfully created a Jets project.

Cd into the project directory:
  cd demo

To start a server and test locally:
  jets server # localhost:8888 should have the Jets welcome page

Scaffold example:
  jets generate scaffold post title:string body:text published:boolean

To deploy to AWS Lambda:
  jets deploy
$

CRUD Scaffold

$ cd demo
$ jets generate scaffold post title:string
      invoke  active_record
      create    db/migrate/20180811022404_create_posts.rb
      create    app/models/post.rb
      invoke  resource_route
       route    resources :posts
      invoke  scaffold_controller
      create    app/controllers/posts_controller.rb
      invoke    erb
      invoke    helper
      create      app/helpers/posts_helper.rb
$

This generates a Post ActiveRecord model and the post controller a simple CRUD app.

Edit Database Config

In the next step, we’ll update the .env.development and set the local database config. For this step, it is helpful to take a quick look at database.yml:

default: &default
  adapter: postgresql
  encoding: unicode
  pool: <%= ENV["DB_POOL"] || 5  %>
  database: <%= ENV['DB_NAME'] || 'demo_dev' %>
  username: <%= ENV['DB_USER'] || ENV['USER'] %>
  password: <%= ENV['DB_PASS'] %>
  host: <%= ENV["DB_HOST"] %>
  url: <%= ENV['DATABASE_URL'] %> # takes higher precedence than other settings

development:
  <<: *default
  database: <%= ENV['DB_NAME'] || 'demo_dev' %>
...

So we can adjust environment variables to configure a local database. My .env.development to looks like this:

.env.development:

DATABASE_URL=postgres://ec2-user@localhost/demo_dev

If you have a password the format would look like this:

DATABASE_URL=postgres://ec2-user:mypassword@localhost/demo_dev

Create DB and Tables

$ jets db:create db:migrate
Created database 'demo_dev'
Created database 'demo_test'
== 20180810215214 CreatePosts: migrating ======================================
-- create_table(:posts)
   -> 0.0062s
== 20180810215214 CreatePosts: migrated (0.0062s) =============================
$

Start the Server

Let’s start the server.

$ jets server
=> bundle exec shotgun --port 8888 --host 127.0.0.1
Jets booting up in development mode!
== Shotgun/WEBrick on http://127.0.0.1:8888/
[2018-08-10 23:01:05] INFO  WEBrick 1.4.2
[2018-08-10 23:01:05] INFO  ruby 2.5.1 (2018-03-29) [x86_64-linux]
[2018-08-10 23:01:05] INFO  WEBrick::HTTPServer#start: pid=13999 port=8888

Test the API

Here’s a curl command that will create posts:

curl -X POST http://localhost:8888/posts \
  -H 'Content-Type: application/json' \
  -d '{
  "post": {
    "title": "My Test Post 1"
  }
}
'

Create a couple of posts and you see something like this when you open http://localhost:8888/posts in a browser:

More curl commands

Here are a few more curl commands for reference:

If you want to update the posts, here’s the curl command:

curl -X PUT http://localhost:8888/posts/1 \
  -H 'Content-Type: application/json' \
  -d '{
  "post": {
    "title": "My Test Post 1"
  }
}
'

To delete the, here’s the curl command:

$ curl -X DELETE http://localhost:8888/posts/1
{"deleted":true}

In this section: