Assertion failure when using UISearchDisplayController in UITableViewController

acib708 picture acib708 · Jan 8, 2013 · Viewed 18.2k times · Source

I've been trying to add simple Search functionality to a TableViewController in my app. I followed Ray Wenderlich's tutorial. I have a tableView with some data, I added the search bar + display controller in storyboard, and then I have this code:

#pragma mark - Table View
     - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
        UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"BreedCell" forIndexPath:indexPath];

        //Create PetBreed Object and return corresponding breed from corresponding array
        PetBreed *petBreed = nil;

        if(tableView == self.searchDisplayController.searchResultsTableView)
            petBreed = [_filteredBreedsArray objectAtIndex:indexPath.row];
        else
            petBreed = [_breedsArray objectAtIndex:indexPath.row];

        cell.accessoryType  = UITableViewCellAccessoryDisclosureIndicator;
        cell.textLabel.text = petBreed.name;

        return cell;
    }

#pragma mark - Search
    -(BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchString:(NSString *)searchString {
        [_filteredBreedsArray removeAllObjects];
        NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF.name contains[c] %@",searchString];
        _filteredBreedsArray = [[_breedsArray filteredArrayUsingPredicate:predicate] mutableCopy];

        return YES;
    }

    -(BOOL)searchDisplayController:(UISearchDisplayController *)controller shouldReloadTableForSearchScope:(NSInteger)searchOption {
        // Tells the table data source to reload when scope bar selection changes

        [_filteredBreedsArray removeAllObjects];
        NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF.name contains[c] %@",self.searchDisplayController.searchBar.text];
        _filteredBreedsArray = [[_breedsArray filteredArrayUsingPredicate:predicate] mutableCopy];
        return YES;
    }

The standard stuff, but when I enter text in the search bar it crashes every time with this error:

2013-01-07 19:47:07.330 FindFeedo[3206:c07] *** Assertion failure in -[UISearchResultsTableView dequeueReusableCellWithIdentifier:forIndexPath:], /SourceCache/UIKit_Sim/UIKit-2372/UITableView.m:4460
2013-01-07 19:47:07.330 FindFeedo[3206:c07] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'unable to dequeue a cell with identifier BreedCell - must register a nib or a class for the identifier or connect a prototype cell in a storyboard'

I understand that in iOS 6 the handling and dequeueing system for cells changed, and also that the search uses a different tableView, so I thought the problem was that the search tableView with the filtered results didn't know about the cell, so I put this in my viewDidLoad:

[self.searchDisplayController.searchResultsTableView registerClass:[UITableViewCell class] forCellReuseIdentifier:@"BreedCell"];

And voila! It worked... Only the first time you search. If you go back to the original results and search again, the app crashes with the same error. I thought about maybe adding all the

if(!cell){//init cell here};

stuff to the cellForRow method, but doesn't that go against the whole purpose of having the dequeueReusableCellWithIdentifier:forIndexPath: method? Anyway, I'm lost. What am I missing? Help, please. Thank you in advance for all your time (:

Alex.

Answer

FunkyKat picture FunkyKat · Jan 8, 2013

Try using self.tableView instead of tableView in dequeueReusableCellWithIdentifier:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
    UITableViewCell *cell = [self.tableView dequeueReusableCellWithIdentifier:@"BreedCell"];

    //Create PetBreed Object and return corresponding breed from corresponding array
    PetBreed *petBreed = nil;

    if(tableView == self.searchDisplayController.searchResultsTableView)
        petBreed = [_filteredBreedsArray objectAtIndex:indexPath.row];
    else
        petBreed = [_breedsArray objectAtIndex:indexPath.row];

    cell.accessoryType  = UITableViewCellAccessoryDisclosureIndicator;
    cell.textLabel.text = petBreed.name;

    return cell;
}

This code works pretty well

Note

If you have custom height cells, do not use

[self.tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];

Use this instead

[self.tableView dequeueReusableCellWithIdentifier:CellIdentifier];