ChangeDispenserController Class

calculateChange(unitsTendered, price)

unitsTendered: An array of instances of some kind of MonetaryUnit subclass. You can assert that the units tendered all have the same currency and that the amount tendered is greater than price. price: Number. You can assert that the units tendered match the currency for price, which is why price is just a number.

Returns true if change can succesfully be dispensed, otherwise returns false to issue a refund and cancel the product.

ChangeDispenser Class

An instance of ChangeDispenser is programmed to physically know what change it has to dispense and physically how to dispense it. Assume that ChangeDispenser is a thin JavaScript layer over native code.

Properties

For every currency unit available, the JavaScript layer dynamically defines properties that match the class name of the monetary units using Object.defineProperty. It defines the properties as read-only properties using getter methods that return new arrays. The new arrays returned from these properties are not referenced internally. For example, var availablePennies = someChangeDispenserInstance.UnitedStatesPennyUnit; would give you an array containing instances of UnitedStatesPennyUnit.

Methods

unitsAvailable(currency)

Describes the types of monetary units available to dispense.

currency: A String value for the currency, i.e. "USD".

Returns an array of objects describing the availablity of monetary units that match the curreny passed in, sorted in descending monetaryValue: [ { propertyName: String (i.e. "UnitedStatesPennyUnit"), unitInfo: { monetaryValue: Number, currency: String, currencySymbol: String } } ]

dispense(units)

Physically dispenses change for all of the monetary unit instances that you pass in.

units: An array of instances of some kind of MonetaryUnit subclass.

Throws an error synchronously if any instance does not exist in its Column Properties.