How should I handle if there is an error occurs when there is no internet connection in Alamofire. I tried checking if data is nil or not but it does not work.
Below
I agree with @Shripada. First you should use Reachability to check for connectivity. There is a Swift library here: https://github.com/ashleymills/Reachability.swift
additionally you can use one of the Alamofire validation methods:
Alamofire.request(.POST, REGISTER_URL, parameters: parameters, encoding: .JSON, headers: getAuthenticationHeader()).validate(statusCode: 200 ..< 300).response { (request, response, data, error) -> Void in
if error != nil {
println("Server responded with: \(response.statusCode)")
return
}
// Handle your response data here
}