Reloading UITableView behind UISearchDisplayController

Question

I\'ve run into this really strange phenomenon that I can\'t quite figure out. I have a UITableViewController that manages a UITableView. Pretty simple. I also have a UISearch

Answer 1

Fixed it..

Add the following lines in viewDidLoad

searchDisplayController.searchResultsTableView.delegate = self;
searchDisplayController.searchResultsTableView.dataSource = self;

That fixed it for me...

Answer 2

I ran into this recently as well...the approach I decided on was to queue updates to the main tableView in a suspended serial dispatch queue until the the UISearchDisplayController hides the searchResultsTableView. I would probably consider this a bug as the section headers should not show through the main tableView if the searchResultsTableView has taken over that layer.

Answer 3

Hopefully you've figured this out by now, but just in case someone stumbles across this question: this is probably happening because your UITableViewController is the data source/delegate for the search table as well as your main table. That is, presumably, you have the same UITableViewDelegate/DataSource methods executing for both table views, and you're returning the same section header for both tables. Make sure you're handling your search results table separately:

- (NSString *)tableView:(UITableView *)aTableView titleForHeaderInSection:(NSInteger)section {
    if (aTableView == [[self searchDisplayController] searchResultsTableView]) {
        return nil;
    }
    // Return a title appropriate for self.tableView here
}

Answer 4

Our solution is to do the following. It has only been tested in iOS 7:

1. In viewForHeaderInSection, return nil if self.searchDisplayController.active is YES
2. In didHideSearchResultsTableView, call [self.tableView reloadData] to reload the headers when the search table disappears

Answer 5

My solution was to avoid reloading the table if search results were displaying, then reloading any time the search results were dismissed.

I had to set a symbolic breakpoint on UITableView reloadData to find all the calls to reload that were causing the section headers to redraw on top of the search table.

Answer 6

UPDATED AGAIN

As it turns out, if a table's header is reloaded in the background it pops in front of the search controller no matter what.

I solved this by disabling the fetchedResultsController (setting it to nil) and letting it load lazily again when needed when the search disappears.

UPDATED - Original answer below

In my case I'm using two fetchedResultsControllers one for the main tableview and one for the search.

I discovered that preventing animations when adding the section headers prevents this bug. So while searchDisplayController.active I simply disable the animation of the section change. see code below.

- (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo
           atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type
{
    if (!self.reordering) {
        UITableView *myTableView = controller == __fetchedResultsController ? self.tableView : self.searchDisplayController.searchResultsTableView;
        UITableViewRowAnimation animation;
        if (self.searchDisplayController.active) {
            animation = UITableViewRowAnimationNone;
        } else {
            animation = UITableViewRowAnimationFade;
        }

        switch(type)
        {
            case NSFetchedResultsChangeInsert:
                [myTableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:animation];
                break;

            case NSFetchedResultsChangeDelete:
                [myTableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:animation];
                break;
        }
    }
}

ORIGINAL ANSWER

The other answer doesn't actually work on it's own. The reason is, the header that is showing is not a header in the searchDisplayController's tableview. It's a header from the main tableview that for some reason is being added above the search table view in the view hierarchy.

I solved this problem by disabling updates to the main tableview while searchDisplayController.active = YES.

In my case I'm using a lazily loaded fetched results controller so I did it like this:

- (void)searchDisplayController:(UISearchDisplayController *)controller didHideSearchResultsTableView:(UITableView *)tableView {
    [self.tableView reloadData];
}

- (void)searchDisplayController:(UISearchDisplayController *)controller willShowSearchResultsTableView:(UITableView *)tableView {
    self.fetchedResultsController.delegate = nil;
    self.fetchedResultsController = nil;
}

However, I still have the problem that if I want to reloadData on the main tableview so it is seen in the background, the section headers still float in front of the darkened area.

Does anyone have a better solution for this? It seems like a legitimate bug for viewForHeaderInSection and titleForHeaderInSection when data is reloaded while covered by a UISearchDisplayController.

The simplest answer for me is to try and override the search view so you can't see the background table. But that takes away from the "Appleness" of the app.