/week_04-day_05-rails-single-resource

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Rails Single Resource

Let's build a rails application!

Objectives

By the end of this, developers should be able to:

  • Follow along in the creation of a rails server.
  • Build a complete server side in Rails.
  • Create a model with full CRUD capability.

Methodical, Error-Driven Development

Status checks will be frequent. As developers we want to be meticulous and make sure we're getting errors where expected as we build our server.

This is called "error-driven development". The goal is to see an error, and to learn what error to expect. Embrace the errors, and they will tell you what your next task is.

Follow the steps outlined in good Error Driven Development

  1. Route
    • Test the route, see that a route does not exist
    • Add the route
    • Test the route, see that a route does exist
  2. Controller
    • Test the route, see that a route does exist but controller does not
    • Add the controller
    • Test the route, see that a controller exists
  3. Model
    • Test the route, see that a controller exists but model does not
    • Add the model
    • Test the route, see that a Model exists
  4. Migrations
    • Test the route, see that a Model exists but migrations must be run
    • Run migrations
  5. View
    • Test the view, see that it does not exist
    • Add the view
  6. Test Feature
    • Test the route, ensure actions are successful
    • Use Rails Console to ensure all data persists as expected

Demo: Books

User Stories

  • Version 1:
    • As a user, I want to view a single book
    • As a user, I want to view all books
    • As a user, I want to create a book with a title and author
    • As a user, I want to edit a book's title and author
    • As a user, I want to delete a book

Entity Relationship Diagram (ERD)

Books
id primary key
title string
author string
created_at datetime
updated_at datetime

CRUD for Books

We'll now go through the steps for completing each CRUD action for multiple resources.

Read - index

  • BooksController#index

Read - show

  • BooksController#show

Destroy

  • BooksController#destroy

Update

  • BooksController#update

Create

  • BooksController#create

Code Along: Hospital

User Stories

  • Version 1
    • As a user, I want to view a single patient
    • As a user, I want to view all patients
    • As a user, I want to create a patient with a first name, last name, diagnosis and born on
    • As a user, I want to edit a patient's first name, last name, diagnosis and born on
    • As a user, I want to delete a patient

Entity Relationship Diagrams

Version 1

Patients
id primary key
first_name string
last_name string
diagnosis string
born_on date
created_at datetime
updated_at datetime

Follow the same Error Driven Development steps as you did with books!

CRUD for Patient

Read - index

  • PatientsController#index

Read - show

  • PatientsController#show

Destroy

  • PatientsController#destroy

Update

  • PatientsController#update

Create

  • PatientsController#create

Lab: Cafeteria

User Stories

  • Version 1
    • As a user, I want to view a single ingredient
    • As a user, I want to view all ingredients
    • As a user, I want to create an ingredient with name and unit
    • As a user, I want to edit an ingredient's name and unit
    • As a user, I want to delete an ingredient

Entity Relationship Diagrams

Version 1

Ingredients
id primary key
name string
unit string
created_at datetime
updated_at datetime

CRUD for Ingredient

Read - index

  • IngredientsController#index

Read - show

  • IngredientsController#show

Destroy

  • IngredientsController#destroy

Update

  • IngredientsController#update

Create

  • IngredientsController#create

Tasks

Developers should run these often!

  • bin/rake routes lists the endpoints available in your API.
  • bin/rake test runs automated tests.
  • bin/rails console opens a REPL that pre-loads the API.
  • bin/rails db opens your database client and loads the correct database.
  • bin/rails server starts the API.

Additional Resources