Tab Bar on Subpages
There are many apps keeping the tab bar on the subpages while many apps are not. It’s not always the best to keep the tab bar persistent because it takes space, but how do we decide whether or not to have the tab bar on subpages?
One of the common relationships between pages is the parent — child relationship with the child page often called subpage. The back button on the navigation bar is the way to leave the subpage. Since a subpage can also have its own subpage and so on, it’s easy to get lost and forget how we end up on the current page.
Tab bar provides the ability to escape.
In the example of App Store, the task switches from viewing updates to discovering new apps seamlessly, but the same time one can easily get stuck in the “loop”.
In this case, the persistent tab bar becomes the life saver:
It not only reminds us how we get here but also provides the exit out of the loop so that we don’t feel stuck.
Be careful with modal view
The App Store just showed a perfect example of using persistent tab bar and interestingly it also has an example of sacrificing tab bar for the modal view experience:
Learnings
Whether or not to have the tab bar on the subpages depends on the app structure. If your app tends to have a simpler structure that doesn’t cause such “loop” then I think it’s ok to not to include a persistent tab bar and save the space for something else if needed.
To me, the most important thing is not to get this single decision right but knowing what to consider when I need to make the next one.
