
| Name | Description | Type | Use | 
|---|---|---|---|
| callback | Passed to verify the status of registration. | undefined | required | 
The PushNotifications listener's callback can be structured as follows:
{
  onRegistrationSucceeded: function(token)  { ... },
  onRegistrationFailed: function({failureType}) { ... }
}| Name | Description | Return type | 
|---|---|---|
| onRegistrationSucceeded | Called if the registration is successful. It passes a registration token. On iOS it is a hex string, while on Android it is raw string value retrieved from GCM servers. | undefined | 
| onRegistrationFailed | Called if an error occurs. It passes the following object: 
 { code, description }
 Possible failure types are listed in the Constants table, in the PushNotifications article. |