How do I go directly to second or third tab when coming to the parent vc?

[junweimah]

So I have some checking before bringing user to the parent's vc which holds all the tabs.

So lets say in parent tab, I have 3 tabs.

After user is done doing something in a previous screen, I want to bring user to the second tab, how do I open the parent's vc and directly lands user in the second tab?

Thanks

[aman198]

Hi,

Create This Method in TabmanViewController class and add below method

Example
class XYZ: TabmanViewController, PageboyViewControllerDataSource {

func scrollToIndex(indexOf:Int) {
    scrollToPage(.at(index: indexOf), animated: false)
}

Usage:
let obj: PagerDirectoryViewController()
obj.scrollToIndex(indexOf:1)

Hope this will Help

[msaps]

@junweimah are you wanting to set a default page index when the view controller is loaded, or moving within the page view controller after doing something in one of the child screens?

[junweimah]

I want to do this

within the page view controller after doing something in one of the child screens?

I already successfully done it by using this line :

self.parentPageboyViewController?.scrollToPage(.first, animated: true)

[junweimah]

Hey, after some progression of my project, I found that I need to go to a specific page when I first enter the parent vc, which is what you said here :

wanting to set a default page index when the view controller is loaded

But I want to control it dynamically, which means I need to do some checking before I decide which page to go

[msaps]

@junweimah this can be achieved with the defaultPage(for:) data source function:

func defaultPage(for pageboyViewController: PageboyViewController) -> PageboyViewController.Page? {
     return .at(index: 2)
}

[junweimah]

This code works, but the indicator remains at the first tab when I land on my parent vc, how do I set it to whichever index I want?

[msaps]

@junweimah this could be a bug, are you saying that the tab bar doesn't respect the default page?

[junweimah]

Yes.

For example after some checking, i want user to go to page 3, yes it indeed landed on page 3, but the indicator remains at page 1.

[msaps]

@junweimah how are you trying to achieve this? The defaultPage() data source function seems to work perfectly fine for aligning the bar and page view controller in my testing.

[junweimah]

This is my exact code at parent vc :

func defaultPage(for pageboyViewController: PageboyViewController) -> PageboyViewController.Page? {
        if(Singleton.shared.goToWhichTabFromMeTab == "favourites"){
            return .at(index: 0)
        }else if(Singleton.shared.goToWhichTabFromMeTab == "savedVouchers"){
            scrollToPage(.at(index: 1), animated: true)
            return .at(index: 1)
        }else{
            scrollToPage(.last, animated: true)
            return .at(index: 2)
        }
    }

In this case i only have 3 tabs to choose where to go to.

[msaps]

@junweimah the scrollToPage() calls are unnecessary. The bar will automatically go to the default page tab. Removing these should fix any issues with the default display.

[junweimah]

Same thing happens

I have changed my code to this :

func defaultPage(for pageboyViewController: PageboyViewController) -> PageboyViewController.Page? {
        if(Singleton.shared.goToWhichTabFromMeTab == "favourites"){
            return .at(index: 0)
        }else if(Singleton.shared.goToWhichTabFromMeTab == "savedVouchers"){
//            scrollToPage(.at(index: 1), animated: true)
            return .at(index: 1)
        }else{
//            scrollToPage(.last, animated: true)
            return .at(index: 2)
        }
    }

I landed on page 3, but the indicator is still at page 1

[junweimah]

I check the example project, and i find that it is working using .at(index: 2), but for some reason my project can't.

The difference I am seeing between the example and mine are

In example project, you have this :

bar.location = .top

In my project, I have this :

bar.location = .preferred
self.embedBar(in: viewCustomBar)

where viewCustomBar is a UIView outlet dragged from storyboard for my bar to embed in.

Could this be the reason causing the bug?

[junweimah]

Yes it is confirmed.

I changed my codes to this :

//        bar.location = .preferred
        bar.location = .top
        bar.appearance = PresetAppearanceConfigs.forStyle(self.bar.style, currentAppearance: self.bar.appearance, 3)
//        self.embedBar(in: viewCustomBar)

Now he default page works as intended.

But for some reasons I have to use my previous code, which are

bar.location = .preferred
self.embedBar(in: viewCustomBar)

Can you kindly fix this bug?

[msaps]

@junweimah I can't seem to reproduce it, even with the bar embedded in an external view.

Could you provide a demo project which reproduces it? Would be much appreciated! 🙂

[junweimah]

Ok I will try to reproduce for you to test.

By the way in the meantime do you test out with 3 or 4 child vc? Something like this :

'
private func initializeViewControllers(count: Int) {
let storyboard = UIStoryboard(name: "Landing", bundle: Bundle.main)
var viewControllers = UIViewController

    for index in 0 ..< count {
        var viewControllerChild = UIViewController()
        switch index{
        case 0:
            viewControllerChild = storyboard.instantiateViewController(withIdentifier: "Me_Favourites_CollectionView_SBID") as! MeFavouritesCollectionViewController
        case 1:
            viewControllerChild = storyboard.instantiateViewController(withIdentifier: "Wallet_Reload_SBID") as! WalletReloadViewController
        case 2:
            viewControllerChild = storyboard.instantiateViewController(withIdentifier: "Me_Events_CollectionView_SBID") as! MeEventsCollectionViewController
        default :
            break
        }
        viewControllers.append(viewControllerChild)
    }
    self.viewControllers = viewControllers
}

`

[junweimah]

I HAVE FOUND THE PROBLEM!!!!

I solved it in my project, this is the things that I have changed :

I commented off these lines

        self.bar.items = [Item(title: title 1),
                          Item(title: title 2),
                          Item(title: title 3)]

and used these lines like in the demo project :
In private func initializeViewControllers(count: Int)

I added :

        var barItems = [Item]()
                        barItems.append(Item(title: "Title: \(index + 1)"))
                bar.items = barItems

And that's it. That's all I changed to remove the bug.

But however I still cannot reproduce the bug using the demo project even reversing what I did to solve the bug

I try using

        self.bar.items = [Item(title: title 1),
                          Item(title: title 2),
                          Item(title: title 3)]

and commenting off

        var barItems = [Item]()
                        barItems.append(Item(title: "Title: \(index + 1)"))
                bar.items = barItems

Both way works in the demo. I dont know which part trigger the bug in my project.

Anyway thanks for the help.

[junweimah]

After solving this bug, I found another bug

I'll open another issue.