Money
Elixir library for working with Money safer, easier, and fun, is an interpretation of the Fowler's Money pattern in fun.prog.
"If I had a dime for every time I've seen someone use FLOAT to store currency, I'd have $999.997634" -- Bill Karwin
In short: You shouldn't represent monetary values by a float. Wherever
you need to represent money, use Money
.
Documentation can be found at https://hexdocs.pm/money/Money.html on HexDocs
USAGE
five_eur = Money.new(500, :EUR) # %Money{amount: 500, currency: :EUR}
ten_eur = Money.add(five_eur, five_eur) # %Money{amount: 10_00, currency: :EUR}
hundred_eur = Money.multiply(ten_eur, 10) # %Money{amount: 100_00, currency: :EUR}
ninety_nine_eur = Money.subtract(hundred_eur, 1) # %Money{amount: 99_00, currency: :EUR}
shares = Money.divide(ninety_nine_eur, 2)
[%Money{amount: 50, currency: :EUR}, %Money{amount: 49, currency: :EUR}]
Money.equals?(five_eur, Money.new(500, :EUR)) # true
Money.zero?(five_eur); # false
Money.positive?(five_eur); # true
Money.Currency.symbol(:USD) # $
Money.Currency.symbol(Money.new(500, :AFN)) # ؋
Money.Currency.name(Money.new(500, :AFN)) # Afghani
Money.to_string(Money.new(500, :CNY)) # ¥ 5.00
Money.to_string(Money.new(1_234_56, :EUR), separator: ".", delimeter: ",", symbol: false)
"1.234,56"
Money.to_string(Money.new(1_234_56, :USD), fractional_unit: false) # "$1,234"
Money.Sigils
# Sigils for Money
import Money.Sigils
iex> ~M[1000]USD
%Money{amount: 1000, currency: :USD}
# If you have a default currency configured (e.g. to GBP), you can do
iex> ~M[1000]
%Money{amount: 1000, currency: :GBP}
Money.Currency
# Currency convenience methods
import Money.Currency, only: [usd: 1, eur: 1, afn: 1]
iex> usd(100_00)
%Money{amount: 10000, currency: :USD}
iex> eur(100_00)
%Money{amount: 10000, currency: :EUR}
iex> afn(100_00)
%Money{amount: 10000, currency: :AFN}
Money.Currency.symbol(:USD) # $
Money.Currency.symbol(afn(500)) # ؋
Money.Currency.name(afn(500)) # Afghani
Money.Currency.get(:AFN) # %{name: "Afghani", symbol: "؋"}
Money.Ecto.Type
Bring Money
to your Ecto project.
The underlying database type is integer
# migration
create table(:my_table) do
add :amount, :integer
end
# model/schema
schema "my_table" do
field :amount, Money.Ecto.Type
end
Phoenix.HTML.Safe
Bring Money
to your Phoenix project.
If you are using Phoenix, you can include money objects directly into your output and they will be correctly escaped.
<b><%= Money.new(12345,67, :GBP) %></b>
INSTALLATION
Money comes with no required dependencies.
Add the following to your mix.exs
:
def deps do
[{:money, "~> 1.2.1"}]
end
then run mix deps.get
.
CONFIGURATION
You can set a default currency and default formatting preferences as follows:
config :money,
default_currency: :EUR,
separator: ".",
delimeter: ",",
symbol: false,
symbol_on_right: false,
symbol_space: false
Then you don’t have to specify the currency.
iex> amount = Money.new(1_234_50)
%Money{amount: 123450, currency: :EUR}
iex> to_string(amount)
"1.234,50"
Here is another example of formatting money:
iex> amount = Money.new(1_234_50)
%Money{amount: 123450, currency: :EUR}
iex> Money.to_string(amount, symbol: true, symbol_on_right: true, symbol_space: true)
"1.234,50 €"
LICENSE
MIT License please see the LICENSE file.