Reload tabBarController after switching language - ios

Question

In the settings section of my app the user has the option to change the language of the app. So when the user chooses spanish as his primary language the app show the content in spanish after he did an app restart but I want to change the language on the fly. This works for the main content like a TableView because I simply can reload the data but the language in my TabBarController does not change because I don't know how.
So I want to update (or better call it a reset) the TabBarController. After the reset it should display all navigation points in the new language.
My idea was to remove the current TabBarController and initialize a new one. Is this possible? Or is there a better way?

Answer 1

I am not an native english speaker so if my explanations aren't clear enough, just tell me and I'll try to rephrase them.
It might look scary and complicated because of my long post, But it really isn't, it is just long because I thought it would be better to also explain how to do it, instead of just giving a few lines of code.
You can achieve what you want using UITabBarController properties.
UITabBarController have a property called tabBar, which is the actual UITabBar.
One might think that in order to achieve what you want, you should edit this property,
HOWEVER, editing this property would cause an exception.
From apple's UITabBarController documentations, regarding the tabBar property:
You should never attempt to manipulate the UITabBar object itself stored in
this property. If you attempt to do so, the tab bar view throws an exception.
So you should never attempt to edit this property at runtime.
After that word of warning, here is what you should do-
UITabBarController also have a property called viewControllers, which is an NSArray who holds reference to the view controllers that being displayed by the tab bar.
This property CAN be modified at runtime, and changes applied to it are updated instantly in the tab bar.
However, for your case, you don't need to modify this property,
But I thought you should know that so if in some situation you will need to add or remove some items from your tab bar, you'll know that can do it.
What you do want to do, is iterate through the objects of that array to access the view controllers themselves.
UIViewController have a property called tabBarItem which represents the UITabBarItem of the view controller.
So what we are basically doing, is getting the tab bar item of the view controller, but instead of getting it from the UITabBarController itself, we are getting it directly from each view controller.
Each UITabBarItem has a title property, and this is what you want to change.
So now, after that long introduction, let's get to the actual code.
I think a pretty easy way to achieve what you want is to iterate thru the viewControllers array, and have some switch statement in there that would change the title.
As in any programming situations, this can be done in countless other ways, so you might have a better way to implement it than my example below, but this should do the trick.
Each view controller that being displayed in a tab bar controller, have a reference to that tab bar using the property tabBarController
So you can run this code in any of the view controllers that being displayed in the tab bar, and simply use self.reference to get a reference to it.
Add this somewhere after the language have changed-
for (int i = 0; i < [self.tabBarController.viewControllers count]; i++) {
if([self.tabBarController.viewControllers[i] isKindOfClass: [UIViewController class]]) {
UIViewController *vc = self.tabBarController.viewControllers[i];
switch(i) {
case 0:
vc.tabBarItem.title = #"primero";
break;
case 1:
vc.tabBarItem.title = #"secondo";
break;
}
}
}
What we are basically doing, is running a for loop that iterating thru all of the items in the array,
The items in the array are in the same order that they appear on the tab bar,
then we use a switch statement to change the title for the view controller in the corresponding position,
Since array have index 0, the first view controller is at position i=0 and the last one is at one less than the count of items in the array.
Some might argue that my if is unnecessary,
Since we already know that this array holds only view controllers, there is no need to check if the item at that position is of UIViewController class, or a subclass of it.
They might be right, but I always say it's better to be safe than sorry.
Of Curse I would also include in your code something to actually check to what language the user have chosen.
The example above changes the titles to spanish, regardless of the user's choice.
Hope it helps mate,
Good luck

Answer 2

#AMI289 gave a good idea.
Make an extension for UITabBarController and do a loop there. Can call anywhere from the tabBarControllers stack.
In my case after the tabBarController goes navigationController.
// MARK: - UITabBarController
extension UITabBarController {
func changeTitleLocale() {
guard let viewContollers = self.viewControllers else { return }
for (index, navVC) in viewContollers.enumerated() {
if let view = navVC as? UINavigationController {
if let topView = view.topViewController {
if topView.isKind(of: ProfileVC.self) {
self.tabBar.items?[index].title = "tab_profile"
} else if topView.isKind(of: ChatVC.self) {
self.tabBar.items?[index].title = "tab_chat"
} else if topView.isKind(of: PicturesVC.self) {
self.tabBar.items?[index].title = "tab_pictures"
} else if topView.isKind(of: VideosVC.self) {
self.tabBar.items?[index].title = "tab_videos"
}
}
}
}
}
}
Then, when we change a language just run it:
self.tabBarController?.changeTitleLocale()