#books #books/tech

Agile Web Development with Rails 7

Cool things I learned

Model Validation

RegEx security

# pay attention to the \z in the RegEx below
validates :image_url, allow_blank: true, format: {
  with: /\.(gif|jpg|png)\z/i,
  message: 'must be a URL for GIF, JPG or PNG image'
}

That \z means "end of line". I would use $ here, but when I do it, I receive this error:

ArgumentError: The provided regular expression is using multiline anchors (^ or $), which may present a security risk. Did you mean to use \A and \z, or forgot to add the :multiline => true option?

Tests

Use #invalid? to check if a product can be persisted

product = Product.new
assert product.invalid?

Check if an object is invalid because of specific fields

assert error messages with I18n.translate

Part 1 - Getting Started

Part II - Building an Application

Chapter 5. The Depot Application

The earlier we discover we've made a mistake, the less expensive it'll be to fix that mistake.

Chapter 6. Task A: Creating the Application

Kickstarting the project

rails new depot --css tailwind
cd depot
# git commit -m 'rails new depot'

rails generate scaffold Product \
  title:string \
  description:text \
  image_url:string \
  price:decimal
# git commit -m 'rails generate scaffold Product'

Edit the *_create_products.rb migration:

# ...
t.decimal :price, precision: 8, scale: 2
# ...

Run the migration:

rails db:migrate

dev # equivalent to `rails server`

# if everything looks fine:
# git commit -m 'specify price precision

Now go to the commit history: https://github.com/meleu/depot/commits/master