I have developed an iPhone application for a café. In the application you can order takeaway food and therefore I need a way to be sure that there are no orders in a “fake” name (e.g. a person who makes an order with a strangers name, e-mail and so on)
Therefore I have to make the user confirm the order before it’s sent to the café. I am not sure what the best way to do this is.
I have been thinking of setting up an SMS gateway and when an order is placed, an SMS is sent to the the entered phone number and the user will have to send a confirmation SMS back. I am not a fan of this approach, as the confirmation is not happening in the application itself.
Then I got the idea that this might be possible with push notifications. I am not exactly sure how it would work (if you have any ideas on this, please let me hear) but since Apple writes the following in their documentation I do not really dare to rely on this for confirmation.
Important: Because delivery is not guaranteed, you should not depend on
the remote-notifications facility for
delivering critical data to an
application via the payload. And never
include sensitive data in the payload.
You should use it only to notify the
user that new data is available.
Another approach which would be very easy to implement would be to programtically retrieve the user’s phone number from the SIM card but I have read that Apple rejects applications which does this.
I would like to ask if you have any ideas how I can do this confirmation? It could be one of the above approaches or a completely new. Would it be possible to do something with the unique ID that the every iPhone has?
Could you do the SMS confirmation, but only once? Keep a link of UDID and phone number pairs, and once a confirmation has been made for a pair then don’t request it again? That way, regular customers will get minimal hassle.
Don’t forget that the UDID for a phone number, or the phone number for a UDID, may change, if the person gets a new device or a new SIM card: make sure your code supports that.