I'm trying to build an iPhone app that allows users to register from their phone itself. At the first page (login form) I have a "register now" button that displays a Registration Form to do just that.
So the workflow now is:
User stars app, load form A
App detects that user is new, UIAlert to say that User needs to register
User has to click 'Register Now' to register (form B)
I'm wondering how I'd improve the app by doing something like this:
User starts app, load form A
App detects that user is new, UIAlert to say that User needs to register
The Registration Form (form B) automagically appears.
I tried implementing some logic in Form A's viewDidLoad like:
//initWithNib:#"RegisterForm" doesn't make a diff
RegisterForm *formB = [RegisterForm new];
formB.navTitle = [NSString stringWithFormat:#"Register New"];
[self presentModalViewController:formB animated:YES];
[formB release];
But that doesn't work, so, what I'm doing wrong?
-(void)viewDidLoad {
If the user hasn't registered
{ RegisterView *view = [[RegisterView alloc] initWithNibName:nil bundle:nil];
[self presentModalViewController:view animated:YES];
[view release];
} else {
}
}
Or, if you're working with multiple views within one XIB file, define the view in the .h file, link it in the XIB file, and then in viewDidLoad, use the same if statement, but use this code instead:
[self.view bringSubviewToFront:registerView];
Related
In my iPhone app, I have the unique identifier for eah project. I want that when the user logs in the unique identifier be accessible on every page.
I am using NSUserDefaults to do that. But the problem is that Login is not the first page. So if I access some page which requires unique id, then it shows "unknownkey".
How can I work around this problem?
Also, I can't add the login screen as first screen as the user can access some portions without login.
try something like
if (![[NSUserDefaults standardUserDefaults] objectForKey: #"uniqueid"]) {
//...user is not logged in..
} else {
//...user is logged in...
}
I guess that this is a design problem rather than a programming problem?
You could probably either move your login screen to the startup screen or leave the tab bar as it is until the user logs in, or even re-design the whole thing differently.
If the login is necessary for everything (e.g. your app is a dropbox client), present the login viewController modally at application start.
And don't dismiss it until you have a successful login.
In your RootViewController's viewDidLoad method, you need to check the saved NSUserDefault via an IF statement. Easy.
-(void)viewDidLoad {
if(![[NSUserDefaults standardDefaults] objectForKey:#"uniqueid"]) {
// here you'll want to present a view modally inside a new navigation controller.
LoginViewController *lvc = [[LoginViewController alloc] initWithNibName:#"LoginViewController" bundle:nil];
UINavigationController *controller = [[UINavigationController alloc] initWithRootViewController:lvc];
[self.navigationController presentModalViewController:controller animated:YES];
} else {
// this is where you'd set up the client if the user is already logged in.
}
}
I've an iPhone application:
When you open the app you see the "LoginView". If you login into application you see a TabBarController. In the third and last tab there is "Logout" button. If you click you see the "LoginView" again. My problem is that if you login again you see the "old" tabbar and the selected tab is the third and not the one, and there is a "Logout" button. Also, if a user login with a different user, see the old data of the previous user (very dangerous).
Here's the code:
- Delegate.h:
UITabBarController *tabBarController;
LoginViewController *loginView;
- Delegate.m (didFinishLaunchingWithOptions):
[self.window makeKeyAndVisible];
loginView = [[LoginViewController alloc] init];
if (YES) { /* if the user is not already logged */
[self.window addSubview:loginView.view];
}
Delegate.m (methods):
- (void)loginComplete {
[loginView dismissModalViewControllerAnimated:YES];
[window addSubview:tabBarController.view];
}
- (void)logoutComplete {
[[tabBarController view] removeFromSuperview];
[tabBarController release];
[window addSubview:loginView.view];
}
And here's the two methods in two different viewcontrollers:
- (IBAction)login:(id)sender {
TabNavisAppDelegate *delegate =
(TabNavisAppDelegate *) [[UIApplication sharedApplication] delegate];
[delegate loginComplete];
}
(the logout method is the same)
Guys, how can I solve this painful problem?
So, here's a list of application that do what I want: "Foursquare", "Brightkite" and others.
Each one have a login screen, a tabbar view and a logout button.
Thanks # everyone.
For login-logout-login situations where all kinds of things need to reset themselves at the logout or the next login, I like to create a notification, something like "NewUserReset." Everything that needs to reset itself to an original state listens for the notification and runs a method that does whatever kind of resetting it needs. The tabbar would change the button title to logout, temporary data structures nil/zero/release themselves, etc.
It's nicely decouples the logout from all of the things that have to be done so you're not trying to manipulate view controllers and data storage and view appearances from the the controller that received the logout tap.
Sending a notification is easy. When the user taps the Logout button you'll send out a notification like this:
[[NSNotificationCenter defaultCenter] postNotificationName:#"JMUserLogout"
object:nil];
You don't have to call it JMUserLogout, you just need a string that you'll recognize and something -- I used your initials -- to help ensure you don't accidentally send a notification that has the same name as a notification something you're unaware of is listening for.
When that notification goes out, any object that has registered with the defaultCenter to listen for #"JMUserLogout" will perform any actions you choose. Here's how your object registers (this should be located in some place like ViewWillLoad or the initialization method of the object):
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(resetForNewUser:)
name:#"JMUserLogout"
object:nil];
The selector there, resetForNewUser:, is just the name of a method you want to run when the notification goes out. That method looks like this:
- (void)resetForNewUser:(NSNotification *)notif {
// DO SOMETHING HERE
}
Where it says // DO SOMETHING HERE you'll add the code specific to your app. For example, you can add the tab bar as an observer of the JMUserLogout notification. In its resetForNewUser: method you'd change the name of the logout button to Login.
In a ViewController or View or data store that holds old data from the previous user the resetForNewUser method would delete all of that data and set things back to the way they should be fore a new user. For example, if the previous user entered data into a UITextField you would delete the text, yourTextFieldName.text = #"";
Lastly, it's important that you also remove your object as an observer before it's deallocated. In your Dealloc method of each object that registered to receive the notification you add this:
[[NSNotificationCenter defaultCenter] removeObserver:self];
Hopefully that makes sense. The Apple documentation for NSNotificationCenter explains more and they provide several sample apps that use notifications.
Seems like tabBarController is not getting released. [ retain count should be 1 before releasing] tabBarController might be retain somewhere. check the retain count of it.
If you want to reset the old data from the previous user after you log out.. all you have to do is reset the UITabBarController's viewControllers property.
So if you are subclassing UITabBarController the following code should restore your app to its original state.
self.viewControllers = #[self.viewControllerOne, self.viewControllerTwo, self.viewControllerThree];
From the documentation:
If you change the value of this property at runtime, the tab bar controller removes all of the old view controllers before installing the new ones. The tab bar items for the new view controllers are displayed immediately and are not animated into position.
The tabBarController object may have been retained somewhere. Try to remove that.
And use the following code for Login, Logout methods
- (void)loginComplete {
// initialize the tabBarController here. like the following
if(tabBarController == nil){
tabBarController = [[UITabBarController alloc] init];
}
[loginView dismissModalViewControllerAnimated:YES];
[window addSubview:tabBarController.view];
}
- (void)logoutComplete {
[[tabBarController view] removeFromSuperview];
[tabBarController release];
tabBarController = nil;
[window addSubview:loginView.view];
}
So that your problem will be solved.
On iPhone, how do I show a login screen to get username and password before giving access to iPhone app? Also, does the iPhone store a cookie to the secure website like a web browser?
I was thinking of giving users to my website a long API key to store in the settings of their iPhone instead of asking them to login with a username/password (seems to be the Slicehost iPhone app approach.) Which is the best way to get a user to login securely? I have full control over the design of the iPhone app and website so have a lot of flexibility.
I have this need in a couple of apps, and I use the following pattern:
In the controller for the first view that gets presented to the user, I have the following test, where UserPrefsManager is a singleton that knows the user credentials. This call causes a modal view to appear (FirstTimeWelcomeViewController) which tells the person that they need to register.
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
UserPrefsManager * prefs = [UserPrefsManager sharedInstance];
if (![prefs isLoggedIn])
{
FirstTimeWelcomeViewController * vc = [[[FirstTimeWelcomeViewController alloc] initWithNibName:#"FirstTimeWelcomeViewController" bundle:nil] autorelease];
[self presentModalViewController:vc animated: false];
}
else
{
if (![[RWXLocationSingleton sharedInstance] hasLocation]) {
[[RWXLocationSingleton sharedInstance] findLocationWithAccuracy:kCLLocationAccuracyThreeKilometers withObject:self andSelector:#selector(updateLocationsView)];
}
[[self tableView ]reloadData];
}
}
FirstTimeWelcomeViewController is basically a screen with buttons that greets people and takes them to the various ways to log in:
-(IBAction) createAccount
{
UIViewController * parent = [self parentViewController];
CreateAccountViewController * vc = [[[CreateAccountViewController alloc] initWithNibName:#"CreateAccountViewController" bundle:nil] autorelease];
[self dismissModalViewControllerAnimated:false];
[parent presentModalViewController:vc animated: false];
}
imagine that these also exist for forgotPassword, and loginACcount... same pattern. This causes the current view to be replaced by a view handling the specific case that they've pressed the button for.
taking the 'loginAccount' method, you've opened the LoginAccountViewController, and it has a method called loginButton, which works something like this...
-(IBAction) loginButton
{
NSString * u = [self.username text];
NSString * p = [self.password text];
//
// app specific logic that tests various inputs and creates a user object.
//
// goes here...
//
if([user checkValid])
{
UserPrefsManager * prefs = [UserPrefsManager sharedInstance];
[prefs setPassword:p];
[prefs setUsername:u];
[self dismissModalViewControllerAnimated:FALSE];
}
//
// more app specific stuff
//
}
And that's pretty much that. You have to use one of the standard ways for putting stuff in the keychain or user defaults to save your information. check that the one you pick lasts between restores if it is something that is annoying for the user to recreate. The first part is the most useful bit, thought the rest might be useful for context.
I'd recommend looking at a technology such as OAuth (http://oauth.net/). This enables the user to authorize access to their account to an application without having to actually enter their username and password into it. Also means you dont have to worry about secure storage of the users credentials, and if their passwords change etc it doesn't matter.
It's used by facebook / twitter and a lot of other big name companies so its not going away (Its actually in the process of getting approved as an offical standard).
You can't restrict access to the app itself but it is trivial to present an initial view that ask for the username and password. If the user does not present the correct information then the app will not allow them to progress to the next view which actually loads the web site.
Likewise, it would be trivial to store a key in the app's sandboxed folders such that neither the user nor anyone else could access it save through the app.
I'm playing around with this application I got on last months Web Designer that's a very basic RSS reader. I would like to add a refresh button to the top navigation bar that refreshes all the content in the table but can't seem to work out how to do it. I've worked out it must somehow use the [tablename Reload] function, but have got no idea how to implement it.
I'm new to all this so simple instructions are good instructions :) I know how to add the button, its linking it to and defining the actions when the user clicks it that I'm struggling with.
You can grab the code here http://www.webdesignermag.co.uk/tutorial-files/issue-162-tutorial-files/ under iPhone Apps (it's the only one).
This is what you need to do in the RootViewController.m:
In the viewDidLoad function, add a button of type UIBarButtonSystemItemRefresh, associate to it an Action and a Target, (infact, as Alan told you, you need to learn about Outlets and Actions)
UIBarButtonItem *refreshButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemRefresh target:self action:#selector(refreshTable)];
self.navigationItem.rightBarButtonItem = refreshButton;
Implement refreshTable function (if not declared in .h, have to put it above viewDidLoad())
- (void)refreshTable{
[rssParser release];
rssParser = [[RSSXMLParser alloc] init];
[rssParser parseRSSFeed];
[self.tableView reloadData];
NSLog(#"table is refreshing ....");
}
Hi Graeme and velcome to SO.
For the iphone UI, you have to define outlets and actions, and use Interface Builder to link them together.
This page has some information that should hopefully get you started.
Understanding Outlets and Actions
i am building up a view-based project with out a navigation bar. I have 2 pages. Simply need a button to link from page one to page two. Then a button to link from page two to page one. Seems it should be very simple but i am having a heck of a time trying to get it.
- (IBAction) view2ButtonPressed: (id) sender {
View2Controller *vc = [[View2Controller alloc] initWithNibName:#"View2" bundle:nil];
[self.navigationController pushViewController:vc animated:YES];
}
Then link the touchedUp action of your button to the view2ButtonPressed method. (Make sure you list the method in your .h file as well)