Objective C: How to reload tableview immediately after switching tabs? - objective-c

I have 2 tabbars in my tabbar controller. I am currently in the second tabbar, after I click on a 'done' button, the tabbar controller needs to switch to the first tab and auto refresh the tableview in it.
I am able to execute on the first part
//Switch to the first tab's view
self.tabBarController.selectedViewController
= [self.tabBarController.viewControllers objectAtIndex:0];
However I need some advise on how to refresh the first view's tableview immediately after the switch is made. Any advise is appreciated.
EDIT: Updated requirement
Note: I do not want the view in the tabbar to reload everytime someone clicks on the tab. The reload should only happen in tab 1's tableview when
1) User is in tab 2
2) User clicks on 'Done button' in tab 2
3) App switches to tab 1 + Reloads the tableview in tab 1
Rationale is that the user will update some information in tab 2 which can only be viewed in tab 1. I want the user to be able to view the updated info immediately after switching to tab 1.

You could just do [tableView reloadData] in the first view's viewDidAppear: method?
EDIT: Editing to add additional data.
General caveat here, Apple tends to frown upon having custom UI Patterns like this. I'm not sure what your app is trying to do here, but you should mostly stick with switching tabs only if the user explicitly clicks on that tab. Have you looked at modal view controllers if you want to present a screen and get some data back, instead of having it in a tab bar?
If not, I guess you could have a solution where the first tab is a delegate of the second tab. When the button is clicked, you could call [delegate doneBtnClicked:] so the control shifts to the first tab. In that function, you could use the setSelectedIndex: to your current tab and call reloadData: on the table view.

You can send NSNotification after
pressing done button on second tab
and handle this notification on first tab controller.

So, create a DONE Button as a UIBarButtonItem, and in it's IBAction, do the following.
For reloading the tableView for the view in the first tab, put that tableView as that class' property , and reference the class like #class class1 , and create an object as a property class1 *object1 for View1 (Tab1) in the class for View2 (Tab2), and access the array1 using object1 like
[class1.object1.array1 reloadData];
And for bringing the view to tab one, use
self.tabBarController.selectedIndex = 0;
Thats pretty much it !
Alternatively you can also use a singleton class for this purpose.

Related

Nav bar button loading a view controller with no controls in it

I am trying to create a ver simple app in iOS 7. In this I need move back and forward using UIBarButtonItem. But when I am pressing back button it is loading a view but not showing all UI Controls properly basically the view is empty. in the below as I pressed any of the cell it will move to another view and load respective data.
On the pressing back button it should show earlier image but it is showing following view.
Please tell me where I am going wrong Thanks in advance.
It seems as if your second screen is presented modally. Then you need to make an unwind segue.
Add this code to the viewcontroller that should be returned to:
-(IBAction)backButtonUnwindSegue:(UIStoryboardSegue *)segue
{
}
then from your modal vc, in storyboard. Drag a segue from the "Back"-button to the Green "Exit"-icon and select the backButtonUnwindSegue-action
Check Out this:
Passing Data example

View Controllers, Popup buttons, AppDelegates, Status Menus, and headaches

This is kinda long but I want to give as many details as possible.
I have created a status bar app. One of the things I've done is made it to where there is a "Settings" menu item that if you click on, an NSWindow pops up with 5 different buttons -- these buttons are tied to their own custom NSViewController so that if you click them, the View Controller changes, but the window remains the same, just like any other StatusBar app.
On one of the view controllers is a popup button with several user selectable options. If I add a button to the specific VC (view controller) and link that to an ibaction that pulls the selected index of the popup button, it works just fine (i.e. I select item 2, it logs item 2).
Now here's where things get. . . odd. I've created a submenu that would in theory allow the user to quickly change the selected item of the popup linked to my custom view controller. Think of this submenu as being labeled 1-4 and clicking one of those items would change the index of the popup button, however every time I try this and follow it up with a NSLog to ensure the button has changed, it ALWAYS reads zero, in other words, it NEVER changes.
Here's what I tried.
Just like with every other view controller I've ever used, I create a new object of my view controller (alloc, init), and reference the popup button object that i've created as a property. This compiles just fine, but returns only zero no matter what is selected.
I've tried calling the method that I know works (the button that is on the view controller containing the popup), but again, this returns only zero no matter what is selected.
Any advice would be greatly appreciated.
tl;dr: can't change a popupbutton on a view controller from the app delegate or nsstatusmenu item, it just always returns zero.
EDIT: I have found a work around since I can communicate to my app delegate just fine, I created an int property and set it to zero. From there, whenever my popupbutton on my VC changes, I change the value of the app delegate int property and just ensure that whenever the nib launches, it set's the selected item to the app delegate property. I feel there has to be a more straight forward way to just get the value of the popup and change it from the app delegate.
EDIT 2: Some code as requested. I realized I needed to point the the view controller by using initwithnibname from the app delegate and then load the view. Doing so allows me to pull the first object in the popup button, any subsequent changes are not recognized unless I do so via my test button on the view controller itself. Also, I'm adding values to my popup in my awakefromnib in the view controller.
searches_VC = [[Searches_ViewController alloc] initWithNibName:#"Searches_ViewController" bundle:nil];
[searches_VC loadView];
NSLog(#"Selected Title: %#",[[searches_VC profilePopupOutlet] titleOfSelectedItem]);

Increasing number of living Views

I've set up a really simple project using storyboards including two views as shown here: http://i.stack.imgur.com/iRx21.png. The navigation can be done by either selecting a cell in the custom table view or hitting the back button labelled with "<<". Everything works fine except the following:
when I switch between the views, every time an instantiation happens. The profiling shows an increasing number of view objects. I would like to keep only one of each view and instantiation should be happen only once. What am I doing wrong? (I'm using ARC.)
Thanks in advance!
You should not link your back button to the parent view controller. This is what causes the new instantiation.
The way to go is to embed the table view into UINavigationController (in IB, choose Editor -> Imbed In -> Navigation Controller. Then change your segue to a Push segue. You can of course hide the navigation bar etc. to make things look exactly as you like. Then, link the back button to the controller with an IBAction and in the handler do a simple
[self.navigationController popViewControllerAnimated:YES];
This would be the appropriate logic of what you are doing. Of course, you can also push the web view modally and then handle the button click with
[self dismissModalViewControllerAnimated:YES];

Make a button to go back to the first of several screens

I am creating an app which has five screens, and each screen has a button called "Home Button".
When the user presses the home button, the user should go back to very first screen.
How can I do this?
I am adding each screen over another screen like this:
[self.view addSubview:myview];
UINavigationController has an array viewControllers of pushed viewControllers.
You can manipulate this array instead of pop commands.
You should have used an existing controller to manage your hierarchy between your views. But anyway, I think what you can do is calling removeFromSuperview on each subview and adding again your very first view. You can do this with :
[self.view.subviews makeObjectPerformSelector:#selector(removeFromSuperview)];
Or you can also tag the views as you add them, and remove only the tagged views to avoid removing your first view from superview.

Adding and Removing UIBarButtonItems to UINavigationBar from Multiple Views

I currently have a Main Window set up as a UINavigationController (also is the root view controller), and I have two views. The first view is the login screen, and the second screen is a table view screen. What I would like to have happen is to show different UIBarButtonItems based on what screen is showing up. For instance, when the logon screen is being displayed, I want a left button on the navigation bar to be displayed (more specifically, it'd be a Settings button before logging in). Once the user logs in, I want the left button to say "Logout" and the right to be a reload button. I've tried programmatically adding the buttons, but they won't show up. Any suggestions?
Also, I've gotten most of this done in IB, but I feel like it would probably be easier to add these buttons programmatically.
All subclasses of UIViewController have a property called navigationItem. While it is readonly, you can alter its properties. So in LoginViewController, you would do self.navigationItem.leftBarButtonItem = /* Code to create the bar button */ and likewise within the TableViewController. Let me know if you need more detail.