[TIMOB-17744] iOS8: Touch ID Feature Request to support separate call for canEvaluatePolicy

Feature Description

Reviewing the documentation and working with the Ti 3.4 SDK we have discovered that the only call available on the touchid module is to the function "authenticate". Without the ability to separately call a function that interfaces with the iOS canEvaluatePolicy:LAPolicyDeviceOwnerAuthenticationWithBiometric we are unable to make a check that determines if Touch ID has being configured correctly on this device. We need to functionality to alert the user when they attempt to setup this feature in our client.

Request

We realize that canEvaluatePolicy is invoked as part of the authenticate function, but this does not suit our needs as we do not want to prompt the user for touch id when all we want to do is determine if its configured. Ideally we would like a function that implements the following:

if ([context canEvaluatePolicy: LAPolicyDeviceOwnerAuthenticationWithBiometrics error:nil]) 
{ 
// return true 
}