pushviewcontroller after uiwebview finishes its load - objective-c

I am properly pushing viewController B from A using navigationController. However, I would like to do it once uiwebview from viewController B finishes its load and not immediately. I tried firstly init B and push A when load ends but with no success, controller is not viewed. How can it be done? thank you.
from controllerA,
self.controllerB = [[BViewController alloc] initWithNibName:#"BViewController" bundle:nil anUser:self.idUser aLang:self.lang];
//[[self navigationController] pushViewController:controllerB animated:NO]; working if pushed directly here
[self.controllerB view];
then, controllerB is initialized, viewDidLoad triggered and when webviewDidFinishLoad, B must be pushed now or viewed at front.
- (void)webViewDidFinishLoad:(UIWebView*)theWebView
{
AViewController *theInstance = [[AViewController alloc] init];
[theInstance pushBcontroller]; }
on AViewController,
-(void)pushBcontroller{
[[self navigationController] pushViewController:self.controllerB animated:NO];
}
not working...

The line AViewController *theInstance = [[AViewController alloc] init]; creates a new instance of a AViewController. Since it's new it isn't part of the view controller hierarchy and is therefore not connected to the navigation controller.
Give your BViewController a reference to the previous controller and use that instead of creating a different one. Or, perhaps better, send a notification when loading is done that the original AViewController uses to know when to change the display.

Related

When do views get created?

I apologize in advance for the n00b question. I am just getting started w/ iOS!
I am trying to push a webViewController onto a navigation controller.
mudWebViewController *webViewController = [[mudWebViewController alloc] initWithNibName:nil bundle:nil];
[[webViewController webView] setDelegate:webViewController];
[[self navigationController] pushViewController:webViewController animated:YES];
But this doesn't seem to work, as I don't see any of the logs in the delegate messages.
If I set the delegate in the viewDidLoad: method, it works fine.
I guess the webView doesn't actually exist at that point, but why? If I initialize the controller, shouldn't the webView be initialized too?
Is viewDidLoad: the right place to be setting up this stuff?
initWithNibName should be not nil, since you obviously are using a nib file to build the view, else you have to create the view in code, which you don't
mudWebViewController *webViewController = [[mudWebViewController alloc] initWithNibName:#"webViewController" bundle:nil];
[[self navigationController] pushViewController:webViewController animated:YES];
Also any delegates should be set either from the Interface builder or from the view itself in the viewDidLoad delegate and not from the previous class, as the object might not been yet initialized in the code so it can fail to set the delegate properly.

How can i make my application allways start with the second view?

I have a Web Service application and it has alogin view. I want to make my application's login view come when the first time app is loaded(installed) and after that it must allways start with a second view. How can i make it? In this link there are some solutions but i think this isn't what i'm looking for. Since mine is a web servise, mean the content of the second view(which i want to be pushed allways) is fetched from a server(i use NSJSONSerialization class for this work)
I would do the login view as a modal view which is only presented when needed.
Edit:
This is VERY brief: (I assume that you are using ARC.)
In AppDelegate:
UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController: mySecondViewController];
if (![self isUserLoggedIn]) {
MyLogInViewController *logInViewController = [[MyLogInViewController alloc] init];
[self presentModalViewController: MyLogInViewController animated: YES];
}
[[self window] setRootViewController: [self navigationController]];
and in logInViewController:
- (void)logInSuccessful {
[self dismissModalViewControllerAnimated: YES];
}

Remove all settings from viewcontroller when dismissed

I got multiple viewcontrollers in my project. The first viewcontroller is called when the application starts and it presents a login screen. When the credentials are correct and the user logs in, the modalview is dismissed. and another viewcontroller is instantiated like this:
[self dismissModalViewControllerAnimated:NO];
Form *formcontroller = [[Form alloc] init];
[self presentModalViewController:formcontroller animated:YES];
When my other viewcontroller is presented the old one disappears. On the top of my secondviewcontroller i got an logout button, wich does exactly the same, so it dismisses the current viewcontroller and calls another like this:
-(IBAction)logOut:(id)sender{
[self dissmissModalViewControllerAnimated:NO];
}
And in my viewdiddisappear:
-(void)viewDidDisappear:(BOOL)animated{
Postform3ViewController *logincontroller = [[Postform3ViewController alloc] init];
[self presentModalViewController:logincontroller animated:YES];
}
The problem is:
When i push the logout button, and i return back to the logincontroller. The Credentials are still filled in. So my conclusion is that the first viewcontroller stays in memory. What am i doing wrong?
Edit:
I did find my own solution. I was profiling my application, and couldn't find any memory leaks. So i decided everything is released. Then i thought that i was able to set everything to empty myself. I did that in the viewDidAppear method like this:
-(void)viewDidAppear:(BOOL)animated {
gebruikersnaam.text = #"";
wachtwoord.text = #"";
[self.activeTextField resignFirstResponder];
[super viewDidAppear:animated];
}
Well first of all when you are using presentModalViewController and pushViewController the VC is retained so you should always release it after you have presented or pushed it.
Secondly in the third block of code it looks like you are creating a logincontroller but presenting a formcontroller. Perhaps you want to be presenting the VC you had just created:
[self presentModalViewController:logincontroller animated:animated];
Edit 0: For your code, in the first block, release like this:
Form *formcontroller = [[Form alloc] init];
[self presentModalViewController:formcontroller animated:YES];
...
[self dismissModalViewController:formcontroller animated:YES];
[formcontroller release];

When "programmatically" creating UINavigationController and UITabBarController, how do I address their functions (like viewWillAppear?)

I am creating my Nav and TabBar in code at launch via:
IN : myAppDelegate.m
- (void)applicationDidFinishLaunching:(UIApplication *)application {
// set up a local nav controller which we will reuse for each view controller
UINavigationController *localNavigationController;
// create tab bar controller and array to hold the view controllers
tabBarController = [[UITabBarController alloc] init];
NSMutableArray *localControllersArray = [[NSMutableArray alloc] initWithCapacity:4];
// setup the first view controller (Root view controller)
RootViewController *myViewController;
myViewController = [[RootViewController alloc] initWithTabBar];
// create the nav controller and add the root view controller as its first view
localNavigationController = [[UINavigationController alloc] initWithRootViewController:myViewController];
// add the new nav controller (with the root view controller inside it)
// to the array of controllers
[localControllersArray addObject:localNavigationController];
// release since we are done with this for now
[localNavigationController release];
[myViewController release];
// setup the first view controller just like the first
ResortsListViewController *resortsListViewController;
resortsListViewController = [[ResortsListViewController alloc] initWithNibName:#"ResortsListView" bundle:nil];
resortsListViewController.title = #"Category1";
resortsListViewController.tabBarItem.image = [UIImage imageNamed:#"image1.png"];
resortsListViewController.navigationItem.title=#"Category1";
localNavigationController = [[UINavigationController alloc] initWithRootViewController:resortsListViewController];
[localControllersArray addObject:localNavigationController];
[localNavigationController release];
// setup the second view controller just like the first
ResortsListViewController *resortsListViewController;
resortsListViewController = [[ResortsListViewController alloc] initWithNibName:#"ResortsListView" bundle:nil];
resortsListViewController.title = #"Category2";
resortsListViewController.tabBarItem.image = [UIImage imageNamed:#"image2.png"];
resortsListViewController.navigationItem.title=#"Category2";
localNavigationController = [[UINavigationController alloc] initWithRootViewController:resortsListViewController];
[localControllersArray addObject:localNavigationController];
[localNavigationController release];
// setup the third view controller just like the first
ResortsListViewController *resortsListViewController;
resortsListViewController = [[ResortsListViewController alloc] initWithNibName:#"ResortsListView" bundle:nil];
resortsListViewController.title = #"Category3";
resortsListViewController.tabBarItem.image = [UIImage imageNamed:#"image3.png"];
resortsListViewController.navigationItem.title=#"Category3";
localNavigationController = [[UINavigationController alloc] initWithRootViewController:resortsListViewController];
[localControllersArray addObject:localNavigationController];
[localNavigationController release];
[resortsListViewController release];
// load up our tab bar controller with the view controllers
tabBarController.viewControllers = localControllersArray;
// release the array because the tab bar controller now has it
[localControllersArray release];
// add the tabBarController as a subview in the window
[window addSubview:tabBarController.view];
// need this last line to display the window (and tab bar controller)
[window makeKeyAndVisible];
}
As you see, I am re-using ResortsListViewController for different category displays (resorts with Beaches, resorts with Pools, resorts with espresso bars) ... now, without harassing me (grin) about the silliness of my categories (cos this is a test app) I need need to do several things:
I need to be able to know which tab click caused the ResortsListViewController to be displayed. I was hoping to use TAG but "initWithRootViewController" does not have the "tag" control. So, if i use an imagefilename that is the category name, I can use that filename to distinguish categories...or even navigationItem name. I need to know if there is a way for ResortsListViewController to know which tabbar item click caused it's display. I thought to look for a "action" that I could assign to the tabbar item, but that is not the way tabbarcontroller works.
When clicking from one tab to another, the view does indeed change, the title of ResortsListViewController changes, etc...but the TABLEVIEW it holds does not clear and display any new data. Searching the web I have found a possible solution:
http://discussions.apple.com/thread.jspa?threadID=1529769&tstart=0
basically saying:
In order for UINavigationControllers
to send
"viewWill/Did/Appear/Disappear"
messages, it needs to have received
"viewWill/Did/Appear/Disappear" from
its container.
What is the container for my UINavigationControllers in this situation? myAppDelegate is defined in the .h file as:
NSObject <UIApplicationDelegate, CLLocationManagerDelegate>
and does not have a:
- (void)viewWillAppear:(BOOL)animated {
}
section. When I add one it says "NSObject may not respond to -viewWillAppear" in the debugger.
Any help out there?
1) This is fairly simple. You need to set the delegate property for the UITabBarController. You would set this to the controller object that owns your tabbarcontroller (or your app delegate if that is your setup). Whichever object is set as the delegate would then receive:
- (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController
AND
- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController
to manage tab selections. Place one of these methods in the implementation of whatever object you set as the delegate (you would want it to be the object that owns all of the controllers).
2) If you have a UIViewController that appears as a tab selection (such as ResortsListViewController) then you would need to put the viewWillAppear method in the controller implementation yourself:
#implementation ResortsListViewController
- (id)initWithNibName:(NSString *)name bundle:(NSBundle *)bundle {
...
}
... etc. ....
- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
[table reloadData];
}
...
#end
Let me know if I misunderstood the second part of your question.
Okay, here goes: This is the correct answer to the question, however, it did not end up being this hard. All I had to do was the following:
Create a property in ResortViewController of type int with variable name whichChoice (for instance). Then address it in the setup of the TabBarController a la:
// setup the first view controller just like the first
ResortsListViewController *resortsListViewController;
resortsListViewController = [[ResortsListViewController alloc] initWithNibName:#"ResortsListView" bundle:nil];
// START HERE IS THE CHANGE
resortsListViewController.whichChoice = 1;
// END HERE IS THE CHANGE
resortsListViewController.title = #"Category1";
resortsListViewController.tabBarItem.image = [UIImage imageNamed:#"image1.png"];
resortsListViewController.navigationItem.title=#"Category1";
localNavigationController = [[UINavigationController alloc] initWithRootViewController:resortsListViewController];
[localControllersArray addObject:localNavigationController];
[localNavigationController release];
To find out which tab was clicked when my resortsListViewController takes over, I simply query the class variable: whichChoice to get the answer.
Things like this are so simple you skip over them. I thought you had to pass the variable in an action and specify where it would go with the target like you do in other objects -- but when you set things up ahead of time you do not have to do that. Now, having said that, dynamically setting "whichChoice" is not so easy without a lot more thought...but setting it to a variable KNOWN at setup is fine.
For answer #2, I simply put a variable style of IBOutlet in my class, hooked it up to the table, and then followed your instructions, because without the variable in the IBOutlet and hooking it up to the table, there is no reference to the table view. For some reason hooking up the table simply to the VIEW "Referencing Outlet" and calling [self.tableview reloadData] did not do the job.
But for the most part, your answers were right and led me in the right direction. As an aside, I really hate that you have to right-click and drag from here-to-there in IB if you have an IB element you built. You should be able to hook it up in code using it's ObjectId (or something). That would be more in line with programmers. I know IB is made to allow programming to be easier for designers, but gee wilikers..it is hard to wrap my mind around! I end up dropping IB and creating elements in code most of time time...which I do not know if is as fast to execute. I tend to think not...but have no proof to the contrary.

How is it possible to come back to the same page?

I am new at Objective C. I am just trying to build an iphone app. I have created some NIB file, and i have gone to other NIB file by creating an object and using this code:
scoreViewController *sviewController = [[scoreViewController alloc] initWithNibName:#"scoreViewController" bundle:nil];
self.scoreView = sviewController;
[sviewController release];
// Setup the animation
[self.navigationController pushViewController:self.scoreView animated:YES];
Now I want to come back to the same page. For this case I have done the same work, but it does not work when I add the previous page header file name.
mainViewController *mainviewController = [[mainViewController alloc] initWithNibName:#"mainViewController" bundle:nil];
self.mcoreView = mainviewController;
[mainviewController release];
// Setup the animation
[self.navigationController pushViewController:self.mcoreView animated:YES];
So, I will be most grateful if you were so nice to post your comment.
I am not 100% sure what you are asking, but I think you want to go back from the the second controller to the first. What you are doing here is instantiating a second instance of the first controller (so you now have 3 controllers), and pushing it onto the stack. Assuming I have this correct, then if you want to move back to the first controller you should be popping the second controller off the stack, not adding a 3rd:
//mainViewController *mainviewController = [[mainViewController alloc] initWithNibName:#"mainViewController" bundle:nil];
//self.mcoreView = mainviewController;
//[mainviewController release];
// Setup the animation
[self.navigationController popViewControllerAnimated:YES];