Marten Money

Marten Money is a Crystal shard that integrates the Money library with the Marten web framework providing a new money field for handling monetary values in your models.

Features

• Drop-in :money field type for Marten models
• Accurate handling of monetary values using the Money type.
• Automatic generation of database fields for amount and currency.
• Support for multiple currencies with ISO 4217 codes.
• Built-in validations via the Money class to ensure data integrity.

Installation

Add the shard to your shard.yml:

dependencies:
  marten_money:
    github: treagod/marten-money

Then, install the dependencies:

shards install

And require it in your src/project.cr:

require "marten_money"

Usage

class Invoice < Marten::Model
  field :id, :big_int, primary_key: true, auto: true

  field :total, :money, blank: false, null: false
end

Creating and Accessing the Money Field

You can create a new Invoice record with a Money object:

invoice = Invoice.create!(total: Money.new(10_00, "USD"))
# Or
invoice = Invoice.create!(
  total_amount: 10_00,
  total_currency: "USD"
)


# underlying columns
puts invoice.total_amount    # => 1000
puts invoice.total_currency  # => "USD"

Accessing the total field:

puts invoice.total.amount     # => 10.0
puts invoice.total.fractional # => 1000
puts invoice.total.currency   # => "USD"

puts invoice.total == Money.new(1000, "USD") # => true

Field Options

Configuration

To configure the Money shard (e.g., set default currency, enable infinite precision), create a Marten initializer:

# config/initializers/money.cr

Money.default_currency = :cad
Money.infinite_precision = true

For more configuration options, refer to the Money shard documentation.

Contributing

Contributions are welcome! Please fork the repository and submit a pull request with your enhancements.