Handle Card Tokens

[judgej]

This is not yet provided by the v1 API, but some background:

Either as a transaction on its own (without taking a payment) or on the back of a payment transaction, SagePay can be asked to store the card details and provide a token for it that the merchant site can store. Future visits to the shop will allow purchases to be made using the token in lieu of the credit card. The user just needs to enter their CV2 code.

For this to work, the following is needed in the API:

• A flag to tell SagePay a token is wanted (CreateToken = 1) in a payment transaction.
• A transaction type that can be used just to receive a token ("registration").
• A token returned from a payment transaction asking for one.
• A token payment type to be used in transactions instead of the card detail.

On that last note, I suspect the API will accept a token and a CV2 to generate a card identifier, which will then carry on as though a full credit card had been entered. Or it may be totally different - we'll have to see.

[judgej]

This has been done as a part of issue #45

It needs some documentation, and perhaps some rethinking to make it a a little more abstract. The "save" and "reusable" flags can be set on the Card request object, which implement the saved tokens for a card. The way they are used is a not at all intuitive, so methods that are a little more clear can perhaps be wrapped around these flags.