ruby 19 lines · 5 steps

Guarding booking dates in a Rails model

A Booking model layers associations, presence checks, and a custom validation to keep date ranges valid.

Explained by highlit

Rails Intermediate validations associations scopes data integrity

1class Booking < ApplicationRecord
2  belongs_to :room
3  belongs_to :guest
4 
5  validates :starts_on, :ends_on, presence: true
6  validate :ends_on_after_starts_on
7 
8  scope :active, -> { where(status: :confirmed) }
9 
10  private
11 
12  def ends_on_after_starts_on
13    return if starts_on.blank? || ends_on.blank?
14 
15    if ends_on <= starts_on
16      errors.add(:ends_on, :after_start, message: "must be after the start date")
17    end
18  end
19end

01 / 01

STEP 01

Walkthrough

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Three takeaways

1Custom validations let you enforce business rules that built-in validators can't express.
2Guarding against blank values inside a validator avoids piling redundant errors on missing fields.
3Scopes package common query conditions into reusable, chainable named methods.

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