Very stuck on an issue
I have a tab bar controller within a navigation controller
The first tab has a calendar on it (which is basically a collection view)
I am trying to make a rightbarbuttonitem to scroll to todays date
I can only seem to create the button within the tabbarcontroller
The function that I call then calls one in the CalendarViewController
but it doesn't seem to work
What is the correct way to implement a bar button item within a tabbarcontroller?
In the tabbarcontroller I have...
navigationItem.rightBarButtonItem = UIBarButtonItem(barButtonSystemItem: .bookmarks, target: self, action: #selector(goToToday))
#objc func goToToday() {
print("pressed")
CalendarViewController().goToToday()
}
In the CalendarViewController I have...
#objc func goToToday(_ animate: Bool = true) {
print("tapped")
calendarView.scrollToDate(Date(),animateScroll: animate)
calendarView.selectDates([Date()])
title = "Test"
}
The function works if I call it from a button in CalendarViewController. And I get both print commands when called from the navigation controller but that's all
You should call gotToToday on the instance you're using as the first tab and not on a new instance as you've done here. Here's what you need to do in gotToToday in TabBarController:
#objc func goToToday() {
print("pressed")
if let calendarViewController = viewControllers[0] as? CalendarViewController {
calendarViewController.goToToday()
}
}
Related
I have a view controller where I need to add a custom back button. So I have added a custom backButtonItem. But After adding custom back button the default behavior of my view controller to go back by swipe stops working as expected.
If I remove the custom back button from the view controller, the behavior of view controller is as expected but as soon as I add custom back button the default behavior stops.
I have added the custom back button like this
self.navigationItem.leftBarButtonItem = getCustomBackBarButtonItem(viewController: self)
I have tried to use backBarButtonItem instead of leftBarButtonItem, but by doing that the custom back button doesn't appear and the view controller's behavior is as expected.
If I remove the above code the behavior of the view controller is as expected and it smoothly goes back by swipe.
Be sure to build the UIBarButtonItem doing something like this:
let customBack = UIBarButtonItem(title: "Back", style:.done, target:self, action: #selector(self.letsGoBack))
and then implement the pop back function with:
#objc func letsGoBack() {
self.navigationController?.popViewController(animated: true)
}
so at the end it's just:
self.navigationItem.leftBarButtonItem = customBack
if you want to keep the swipe back gesture, you might subclass your navigation controller doing so:
class YourNavigationController: UINavigationController, UIGestureRecognizerDelegate {
override func viewDidLoad() {
super.viewDidLoad()
self.interactivePopGestureRecognizer?.delegate = self
}
public func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldBeRequiredToFailBy otherGestureRecognizer: UIGestureRecognizer) -> Bool {
return self.viewControllers.count > 1
}
}
Instead of setting delegate to self you can simply add this line:
self.navigationController?.interactivePopGestureRecognizer?.delegate = nil
So it won't go to any of interactive PopGestureRecognizer's delegate method and the navigation Controller behavior will be as per your expectation. This is the small workaround to achieve the expected behavior.
To navigate back to previous viewController
Initialize UIBarButton
var backBtn:UIBarButtonItem!
add UIBarButton to NavigationBar
backBtn = UIBarButtonItem(title: "Go-Back" , style: .plain, target: self, action: #selector(self.backBtnClicked(_:)))
self.navigationItem.leftBarButtonItem = backBtn
add this function into your class
func backBtnClicked(_ sender:UIBarButtonItem) {
if let redirect = self.navigationController?.popViewController(animated: true) {
// If you open this viewController by using pushViewController this will called
} else {
self.dismiss(animated: true, completion: nil)
// If you open this viewController by using present this will called
}
}
Hope this will help you
How do I add a button to navigation bar that appears only in a particular view controller? And also how to add different buttons to different view controller that is embedded in navigation controller.
You don't have to add buttons to navigation bar, rather you could add bar button items. If you want you can customise bar button item to meet your requirements like setting a custom image as suggested by #Pushpendra.
Programatically:
Your View Controller is responsible for providing bar button item(s) for it's navigation bar. Create bar button items inside each of your view controller's viewDidLoad() or in init() if you have overridden it.
Storyboards:
It's pretty handy to drag n drop bar button items from storyboard editor and have the outlets setup so that you can change the behaviour later.
If you are precisely looking to control the behaviour, then you can add or remove a bar button as and when needed depending on your conditional requirements.
class FooViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
/// Assuming this view controller presented/pushed with navigation controller
let buttonItem = UIBarButtonItem(barButtonSystemItem: .save, target: self, action: #selector(FooViewController.buttonItemAction(sender:)))
self.navigationItem.leftBarButtonItem = buttonItem
}
#IBAction func buttonItemAction(sender: UIBarButtonItem) {
/// some action
}
}
class BarViewController: UIViewController {
var buttonItem: UIBarButtonItem?
var showButtonItem = false
override func viewDidLoad() {
super.viewDidLoad()
/// Assuming this view controller presented/pushed with navigation controller
buttonItem = UIBarButtonItem(barButtonSystemItem: .bookmarks, target: self, action: #selector(BarViewController.buttonItemAction(sender:)))
self.navigationItem.leftBarButtonItem = buttonItem
}
#IBAction func buttonItemAction(sender: UIBarButtonItem) {
/// some action
}
#IBAction func toggleButtonItem(sender: UIButton) {
self.navigationItem.rightBarButtonItem = (self.showButtonItem == true) ? self.buttonItem : nil
}
}
If this is what you are not looking for then update your question along with the code that you have tried.
try this :-
extension UIViewController {
func addButton(img:String){
let imgIcon = UIImage(named: img)
let btn = UIBarButtonItem(image: imgIcon, style: .plain, target:
self, action: #selector(self.btnAction))
// if you want to set right button then add right bar button item
self.navigationItem.leftBarButtonItem = btn
}
func btnAction(){
}
func removeButton() {
self.navigationItem.leftBarButtonItem = nil
}
}
when you want to add button
in viewDidLoad :-
self.addButton(img:"imageName")
also if you want to perform separate action on all view controller then
call this on controller
override func btnAction() {
}
to remove :-
self.removeButton()
if you want to add different button on different controller add the button in viewDidLoad and remove in viewWillDisappear
Drag a bar button item in your navigation bar for the specific view controller in your storyboard
The best solution is
Create Viewcontroller inherit from UIViewController or UITableViewController and write a method for setupNavigationButton or buttonText or
(Better to add an action method on a super controller also)
eg:
-(void) setupNavigationButton {
self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc]initWithTitle:#"button1" style:UIBarButtonItemStylePlain target:self action:#selector(buttonActin:)];
}
and call this method on viewDidLoad on the created controller
Next when you create your own controller add this viewcontroler as your parent view controller. So it will automatically add that view.
(You want to write an action on your controller)
Using above method, it saves only one line. But you can save more lines. Let's assume you want to change only text and action on that button.
If it is only you need to change text, write a method to return button text
(Following line for your baseviewcontroller)
-(NSString *) rightButtonText {
return #"";
}
and add following codes for baseviewcontroller
-(void)setNavigationControler {
self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc]initWithTitle:[self rightButtonText] style:UIBarButtonItemStylePlain target:self action:#selector(buttonActin:)];
}
and call it on baseviewcontroller
Now your every view controller, you need to override rightButtonText and create selector method and do that action.
Assume you don't need to add that button for some viewcontroler. Then you have a few options
1) Remove baseviewcotroler inheritance from your viewcontroller
2) After call supper viewDidload add following code
self.navigationItem.rightBarButtonItem =
3) Override setNavigationControler method on your controller with the blank method body.
-(void)setNavigationControler {}
In my root view controller I set an array of bar button items with images and assign them to the right bar button.
When I push the next view controller my navigation bar resets and only displays a back button.
Any way to preserve the navigation bar as it was set on the root view controller so it will display on all pages?
As user1046037 has said you can set the item buttons while you are preparing the segue.
Example:
let helpViewController = HelpViewController(nibName: "HelpViewController", bundle: nil)
let someLeftButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.refresh, target: self, action: "someAction")
helpViewController.navigationItem.leftBarButtonItem = someLeftButton
helpViewController.navigationItem.leftItemsSupplementBackButton = true
navigationController?.pushViewController(helpViewController, animated: true)
This one is to preserve the left button item and the back one.
helpViewController.navigationItem.leftItemsSupplementBackButton = true
If you are going to use the same button in several Viewcontrollers you can create a BaseViewController setting up the button and his behaviors.
class AHBaseViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
configureNavigationBar()
// Configure Common status bar if you want too.
}
func configureNavigationBar() {
let someLeftButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.refresh, target: self, action: "someAction")
navigationItem.leftBarButtonItem = someLeftButton
navigationItem.leftItemsSupplementBackButton = true
}
}
Then just inherit it, in the viewControllers that you want to show the button(s).
class HelpViewController: AHBaseViewController {
override func viewDidLoad() {
super.viewDidLoad()
}
}
When you segue between view controllers using Push, you're going to get the default "horizontal slide" navigation animation which. Try "present Modally" or "present as popover".
I have a question regarding the navigation bar.
As far as I understand from iOS: A view controller opened by a segue inherits the navigation bar of the parent view controller. Is this correct so far?
Is there a view controller within a stack "owns" the navigation bar in a complex segue stack (e.g. TableViewController that opens a TabBarController that opens ...)?
I very often run into the problem that I don't know where to get the actual navigation item in order to set the title or a bar button item.
In this case, I have the following controllers:
TabBarController
EventPostsViewController -> To display a list of posts, is a tabbed view within the TabBarController
CreatePostViewController -> To write a new post
So within the EventPostsViewController I can do this (and it works):
class EventPostsViewController: UITableViewController {
...
override func viewWillAppear(animated: Bool) {
...
// This solution works, but only for EventPostsViewController
self.tabBarController?.navigationItem.title = "text"
But within the CreatePostViewController, which is opened by a segue via EventPostsViewController, neither of this solutions work.
class CreatePostViewController: UIViewController {
...
override func viewWillAppear(animated: Bool) {
...
// Neither of these solutions works
self.navigationItem.title = "Text"
self.tabBarController?.navigationItem.title = "Text"
self.navigationController?.navigationItem.title = "Text"
How do I get the actual navigation bar/navigationItem?
Stupid simple mistake I repeat every time :)
I forgot to link my custom CreatePostViewController with the view controller using the interface builder.
This code now works:
class CreatePostViewController: UIViewController {
...
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated);
self.navigationController?.setNavigationBarHidden(false, animated: false)
// Set title
self.navigationItem.title = "Write Post"
// Add Submit button
var submitButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.Done, target: self, action: "submitPost:")
self.navigationItem.rightBarButtonItem = submitButton
}
...
}
So here's my problem.
I added a empty ViewController to a NavigationController.
The problem is that when I add a View to the empty ViewController the navigation bar becomes unclickable I can't add back buttons or change the title.
I'm using Xcode 6.1 6A1052d.
You don't add buttons directly to navigation, but to the navigationItem of contained view controller. For example,
class ContainedViewController : UIViewController {
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
self.navigationItem.leftBarButtonItem = UIBarButtonItem(barButtonSystemItem: .Add, target: nil, action: nil)
}
}