I want to know which cells are not visible anymore of a UITableView so I can delete their data from the DataModel class where they are stored.

This is what I have tried but does not work. I guess because indexPathsForVisibleRows can't be used as publisher.

  func addSubscriberToVisibleCells(){
        var publisher = self.table_view.indexPathsForVisibleRows.publisher.receive(on: DispatchQueue.main)
        print("Publisher added")
        
        publisher.sink { pathsVisible in
            
            guard pathsVisible != nil  else{return}
            
            self.lastIndexPathRows.forEach { lastIndex,value in
                if pathsVisible.firstIndex(of: lastIndex) == nil {
                    self.postData.deleteDataForIndex(lastIndex)
                    self.lastIndexPathRows.removeValue(forKey: lastIndex)
                }
            }
            pathsVisible.map { visibleIndexPath in
                self.lastIndexPathRows[visibleIndexPath] = 1
            }
        }
    }

self.lastIndexPathRows is a dictionary to keep track of the latest visible cells.

CodePudding user response：

Implement tableView(_:didEndDisplaying:forRowAt:) in your table view delegate.