findObjectsInBackgroundWithBlock shows no results - ios

Question

I am trying to search my objects on parse.com using a uisearchbar and performing 'findObjectsInBackgroundWithBlock'. I am getting the correct results in my output but they are not showing up in my table.
I was previously doing this without blocks, my code worked, it got the correct results but moved very slowly and I was getting a warning, "Warning: A long-running Parse operation is being executed on the main thread"
I had previously been using the code:
- (void)filterResults:(NSString *)searchTerm {
[self.searchResults removeAllObjects];
PFQuery *query = [PFQuery queryWithClassName: #"Items"];
[query whereKeyExists:#"itemName"];
[query whereKeyExists:#"itemDescription"];
[query whereKey:#"tags" containsString:searchTerm];
NSArray *results = [query findObjects];
NSLog(#"%#", results);
NSLog(#"%u", results.count);
[self.searchResults addObjectsFromArray:results];
}
So now I am trying findObjectsInBackgroundWithBlock instead, I have not worked with blocks before so this is where I need help, here is my new code:
- (void)filterResults:(NSString *)searchTerm {
[self.searchResults removeAllObjects];
PFQuery *query = [PFQuery queryWithClassName: #"Items"];
[query whereKey:#"tags" containsString:searchTerm];
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
NSLog(#"%#", objects);
NSLog(#"%u", objects.count);
[self.searchResults addObjectsFromArray:objects];}];
Here is some more of my code
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
if (tableView == self.tableView) {
return self.objects.count;
} else {
return self.searchResults.count;
}
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath object:(PFObject *)object {
NSString *uniqueIdentifier = #"cell";
HomeCell *cell = nil;
cell = (HomeCell *) [self.tableView dequeueReusableCellWithIdentifier:uniqueIdentifier];
if (!cell) {
NSArray *topLevelObjects = [[NSBundle mainBundle] loadNibNamed:#"HomeCell" owner:nil options:nil];
for (id currentObject in topLevelObjects)
{
if([currentObject isKindOfClass:[HomeCell class]])
{
cell = (HomeCell *)currentObject;
break;
}
}
}
if (tableView != self.searchDisplayController.searchResultsTableView) {
NSString *itemName = [object objectForKey:#"itemName"];
NSString *itemDescription = [object objectForKey:#"itemDescription"];
//cell.textLabel.text = last;
cell.cellTitleLabel.text = itemName;
cell.descriptionLabel.text = itemDescription;
cell.priceLabel.text = [object objectForKey:#"price"];
PFFile *thumbnail = [object objectForKey:#"imageFile"];
PFImageView *thumbnailImageView = cell.imageFile;
thumbnailImageView.image = [UIImage imageNamed:#"Facebook #2x.png"];
thumbnailImageView.file = thumbnail;
[thumbnailImageView loadInBackground];
}
if ([tableView isEqual:self.searchDisplayController.searchResultsTableView]) {
PFObject *obj2 = [self.searchResults objectAtIndex:indexPath.row];
PFQuery *query = [PFQuery queryWithClassName:#"Items"];
PFObject *searchedItems = [query getObjectWithId:obj2.objectId];
NSString *itemName = [searchedItems objectForKey:#"itemName"];
NSString *itemDescription = [searchedItems objectForKey:#"itemDescription"];
cell.cellTitleLabel.text = itemName;
cell.descriptionLabel.text = itemDescription;
cell.priceLabel.text = [searchedItems objectForKey:#"itemName"];
PFFile *thumbnail = [searchedItems objectForKey:#"imageFile"];
PFImageView *thumbnailImageView = cell.imageFile;
thumbnailImageView.image = [UIImage imageNamed:#"Facebook #2x.png"];
thumbnailImageView.file = thumbnail;
[thumbnailImageView loadInBackground];
}
return cell;
Any help would be greatly appreciated,
cheers

Answer 1

In order to update the table view, you need to call the reloadData: method once you have added the new search results. Make sure that you call this method within the block that you provide to findObjectsInBackgroundWithBlock: because this block of code will be run on a separate thread. This causes the method to return instantly, and code after this method will then run before the block has actually executed. Your find objects code within filterResults: should look something like this:
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
// This block is called from a background thread once the query has been executed
NSLog(#"%#", objects);
NSLog(#"%u", objects.count);
[self.searchResults addObjectsFromArray:objects];
// Refresh the table view on the main thread
dispatch_async(dispatch_get_main_queue(), ^{
[self.tableView reloadData];
[self.searchDisplayController.searchResultsTableView reloadData];
});
}];

Answer 2

Differentiate from your search table view and your regular tableview when you create the cells.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath object:(PFObject *)object {
if (tableView = self.tableView) {
//Configure your cell normally
}
else {
//Configure your cells using
cell.someAttribute = self.searchResults[indexPath.row].someAttribute;
}