Is there any way to write concise code for below case - ios

Question

I have an app which has two tabs. In the first BookVC tab, I use UICollectionViewController to show books and in didSelectItemAtIndexPath i call a function that push the BookDetailVC.
And in Bookmark tab, i want to show all books which was bookmarked and when user select certain book, i want to push BookDetailVC. I know it can be achieved by writing the same code as in BookVC. But i don't want to repeat the same code.
I'd tried to make BookmarkVC subclass of BookVC and ended up as showing the same book in both BookVC and BookmarkVC since i'm using the same one instance of UICollectionView from BookVC. Is there any way to override UICollectionView of BookVC or any other approach to solve. Sorry for my bad english. Thanks.

Answer 1

You are taking the wrong approach. The way you describe your bookmarks and your books View controller, it seems to me that they are identical, the only thing that changes is the content.
So, since collection views use data sources all you have to do is change the Data source based on whether you wanna show all books, or only the bookmarked ones.
Added code:
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let viewController = storyboard.instantiateViewController(withIdentifier :"secondViewController") as! UIViewController
self.present(viewController, animated: true)

Answer 2

I think you are doing wrong use just need to reload collection view based on which button is clicked take boolean
isBookMarkCliked:Bool
For Better Readablity create Model For Book
like
class Book {
var title: String
var author: String
var isBookMarked:Bool
init(title: String, author: String, isBookMarked:Bool) {
self.title = title
self.author = author
self.isBookMarked = isBookMarked
}
}
and declare two array globally with Book Model
arrForBooks:[Book] = []
arrForBookMarkedBooks:[Book] = []
Create CollectionViewDelegate methods using extension
extension YourClassVC: UICollectionViewDataSource,UICollectionViewDelegate
{
//MARK: UICollectionViewDataSource
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int
{
if isBookMarkClicked
{
return arrForBookMarkedBooks.count
}
return arrForBooks.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell
{
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "CellIdentifier", for: indexPath) as! YourCellClass
var currentBook:Book = nil
if isBookMarkClicked
currentBook = arrForStoreDetails[indexPath.row]
else
currentBook = arrForBookMarkedBooks[indexPath.row]
//Set data to cell from currentBook
return cell
}
//MARK: UICollectionViewDelegateFlowLayout
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
collectionView.deselectItem(at: indexPath, animated: false)
//Your code to push BookDetailVC
}
}