STPFormEncodable

The root object name to be used when converting this object to a form-encoded string. For example, if this returns “card”, then the form-encoded output will resemble “card[foo]=bar” (where ‘foo’ and ‘bar’ are specified by propertyNamesToFormFieldNamesMapping below.

This maps properties on an object that is being form-encoded into parameter names in the Stripe API. For example, STPCardParams has a field called expMonth, but the Stripe API expects a field called exp_month. This dictionary represents a mapping from the former to the latter (in other words, STPCardParams.propertyNamesToFormFieldNamesMapping()[“expMonth”] == “exp_month”.)

You can use this property to add additional fields to an API request that are not explicitly defined by the object’s interface. This can be useful when using beta features that haven’t been added to the Stripe SDK yet. For example, if the /v1/tokens API began to accept a beta field called “test_field”, you might do the following: var cardParams = STPCardParams() // add card values cardParams.additionalAPIParameters = [“test_field”: “example_value”] STPAPIClient.shared.createToken(withParameters: cardParams completion:…);