save login session credentials and loading throughout the app - ios

Question

I am new to iOS development. I am developing photo sharing app. In this , First i need to use Web service for Login page. Web service is in PHP and return response in JSON. I want to save login session throughout the app . When user launches the app then it always check whether the user is logged in or not. Please give me suitable solution for this very soon as there is deadline of my job if i don`t do this in early time. Here is my Code.
**<HomeKiddoAppDelegate.h file>**
#import <UIKit/UIKit.h>
#class HomeKiddoViewController;
#interface HomeKiddoAppDelegate : UIResponder <UIApplicationDelegate>
#property (strong, nonatomic) UIWindow *window;
#property (strong, nonatomic) HomeKiddoViewController *viewController;
#end
**<HomeKiddoAppDelegate.m file>**
#import "HomeKiddoAppDelegate.h"
#import "HomeKiddoViewController.h"
#implementation HomeKiddoAppDelegate
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions: (NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
// Override point for customization after application launch.
self.viewController = [[HomeKiddoViewController alloc] initWithNibName:#"HomeKiddoViewController" bundle:nil];
self.window.rootViewController = self.viewController;
[self.window makeKeyAndVisible];
//Register defaults
NSMutableDictionary *defaultsDictionary = [[NSMutableDictionary alloc] init];
[[NSUserDefaults standardUserDefaults] registerDefaults: defaultsDictionary];
return YES;
}
- (void)applicationWillResignActive:(UIApplication *)application
{
}
- (void)applicationDidEnterBackground:(UIApplication *)application
{
}
- (void)applicationWillEnterForeground:(UIApplication *)application
{
}
- (void)applicationDidBecomeActive:(UIApplication *)application
{
}
- (void)applicationWillTerminate:(UIApplication *)application
{
}
#end
> #import <UIKit/UIKit.h>
> #import "SignInViewController.h"
>
> #interface HomeKiddoViewController : UIViewController{
> SignInViewController *signInViewController;
> }
>
> -(IBAction)signInClicked:(id)sender;
>
> #end
**<HomekiddoViewController.m>**
> #import "HomeKiddoViewController.h"
>
> #interface HomeKiddoViewController ()
>
> #end
>
> #implementation HomeKiddoViewController
>
> - (void)viewDidLoad
> {
> [super viewDidLoad];
> }
>
> - (void)viewDidUnload {
> [super viewDidUnload]; }
>
> - (BOOL)shouldAutorotateToInterfaceOrientation: (UIInterfaceOrientation)interfaceOrientation {
> return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown); }
>
> -(IBAction)signInClicked:(id)sender{
> if(signInViewController==nil){
> signInViewController=[[SignInViewController alloc]initWithNibName:#"SignInViewController" bundle:nil];
> }
> [self.view addSubview:signInViewController.view];
> } #end
>
>
**<SignInFormViewController.h>**
> #import <UIKit/UIKit.h>
> #import "SBJson.h"
>
> #interface SignInFormViewController : UIViewController
> <NSURLConnectionDelegate>
{
> IBOutlet UITextField *email1;
> IBOutlet UITextField *password1;
> NSURLConnection *conn;
> NSMutableData *webData;
> IBOutlet UITextView *textView;
> }
#
property (nonatomic, retain) IBOutlet UITextField *email1; #property
> (nonatomic, retain) IBOutlet UITextField *password1;
>
>
-(IBAction)btnSignInClicked:(id)sender;
> -(IBAction)backClicked:(id)sender;
>
> #end
>
import "SignInFormViewController.h"
#interface SignInFormViewController ()
#end
#implementation SignInFormViewController
#synthesize email1;
#synthesize password1;
- (void)viewDidLoad
{
[super viewDidLoad];
}
- (void)viewDidUnload
{
[super viewDidUnload];
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}
-(IBAction)btnSignInClicked:(id)sender{
NSString *queryUrl=[NSString stringWithFormat:#"Url of the web service with parameters",email1.text,password1.text];
NSURL *url=[NSURL URLWithString:queryUrl];
NSMutableURLRequest *request=[NSMutableURLRequest requestWithURL:url];
conn=[[NSURLConnection alloc] initWithRequest:request delegate:self];
if(conn)
{
webData=[NSMutableData data];
NSLog(#"in Connection if statement");
}
}
-(void) connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *) response{
[webData setLength: 0];
NSLog(#" inside didReceiveZResponse");
}
-(void) connection:(NSURLConnection *)connection didReceiveData:(NSData *) data {
[webData appendData:data];
NSLog(#"inside did receive data");
}
-(void) connection:(NSURLConnection *)connection didFailWithError:(NSError *) error {
NSLog(#"in fail with error");
}
-(void) connectionDidFinishLoading:(NSURLConnection *)connection{
[email1 resignFirstResponder];
[password1 resignFirstResponder];
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:email1.text forKey:#"email"];
[defaults setObject:password1.text forKey:#"password"];
[defaults synchronize];
}
-(IBAction)backClicked:(id)sender{
[self.view removeFromSuperview];
}
#end

Answer 1

I'm gonna give you a comprehensive answer.
Don't use NSUserDefaults and don't store password it's a bad solution
Let's create a structured user class instead
When the user logged in, you will need to make sure you have access to user data throughout the app so you can get the data on any screen when you need it.
To achieve this, we need to make a great structure to organize this properly. Remember that current user and another users are both "users" so we will use the same class.
Create a class and name it "EDUser" (you can choose other name if you want).
This class will contain a user information (either current user or other user).
More than that, this class will have capability to log the user in.
Here's a picture of what the class might look like:
class EDUser {
var firstName: String
var lastName: String?
var birthDate: NSDate?
init(firstName: String, lastName: String?, birthDate: NSDate?) {
self.firstName = firstName
self.lastName = lastName
self.birthDate = birthDate
}
}
// MARK: - Accessor
extension EDUser {
class var currentUser: EDUser? {
get {
return loadCurrentUserFromDisk()
}
set {
saveCurrentUserToDiskWithUser(newValue)
}
}
}
// MARK: - Log in and out
extension EDUser {
class func loginWithUsername(username: String,
andPassword password: String,
callback: (EDUser?, NSError) -> Void) {
// Access the web API
var parameters = [
"username": username,
"password": password
]
YourNetworkingLibrary.request(.POST,
"https://api.yourwebsite.com/login",
parameters: parameters).responseJSON {
response in
if response.statusCode == .Success {
let user = EDUser(firstName: response["firstName"],
lastName: response["lastName"],
birthDate: NSDate.dateFromString(response["birthDate"]))
currentUser = user
callback(currentUser, nil)
} else {
callback(nil, yourError)
}
}
}
class func logout() {
deleteCurrentUserFromDisk()
}
}
// MARK: - Data
extension EDUser {
class private func saveCurrentUserToDiskWithUser(user: EDUser) {
// In this process, you encode the user to file and store it
}
class private func loadCurrentUserFromDisk() -> EDUser? {
// In this process, you get the file and decode that to EDUser object
// This function will return nil if the file is not exist
}
class private func deleteCurrentUserFromDisk() {
// This will delete the current user file from disk
}
}
// MARK: - Helper
extension NSDate {
class func dateFromString(string: String) -> NSDate {
// convert string into NSDate
}
}
Use Case
Now with everything in place, we can use it like this
Non-blocking logging in process
EDUser.loginWithUsername(username: "edward#domain.com",
password: "1234") {
user, error in
if error == nil {
// Login succeeded
} else {
// Login failed
}
}
Logging out
EDUser.logout()
Check whether the user is logged in
if EDUser.currentUser != nil {
// The user is logged in
} else {
// No user logged in
// Show the login screen here
}
Get current user data on any screen
if let currentUser = EDUser.currentUser {
// do something with current user data
}
Store other user as object
let user = EDUser(firstName: "Edward",
lastName: "Anthony",
birthDate: NSDate())

Answer 2

You can save the login data in the NSUserDefaults like this.
NSUserDefaults *userDefaults = [NSUserDefaults standardUserDefaults];
[userDefaults setObject:cookieString forKey:#"Cookie"];
[userDefaults setObject:pwString forKey:#"Password"];
[userDefaults synchronize];
Then you can load the user default from anywhere you like in the app with
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *myString = [defaults objectForKey:#"Cookie"];

Answer 3

the simplest solution is to use keychain.
Another simple method is to save the login credentials in a locale file (txt, xml or even an sqldb).