I'm trying to remove cells from UICollectionView in for.. in loop and every time I get NSRangeException. I can't understand why does it happen because firstly I sort my array and then trying to remove. So the problem is that I firstly try to send request to the server and only if response is succes my UICollectionView cells and array elements are removes. Here is my code:
Pass elements through the loop:
- (IBAction)deletePictures:(id)sender {
int i = 0;
if (selectedPhotosURL.count>0){
loadCount = (int)selectedPhotosURL.count;
//sorting an array (it works fine)
NSArray *indexPaths = sortMediaCollection.indexPathsForSelectedItems;
NSMutableArray *pathes = [NSMutableArray arrayWithArray:indexPaths];
NSSortDescriptor *highestToLowest = [NSSortDescriptor sortDescriptorWithKey:@"self" ascending:NO];
[pathes sortUsingDescriptors:[NSArray arrayWithObject:highestToLowest]];
[selecedCellsArray sortUsingComparator:^NSComparisonResult(NSString *str1, NSString *str2) {
return [str2 compare:str1 options:(NSNumericSearch)];
}];
NSLog(@"selectedCElls %@",selecedCellsArray);
for(NSIndexPath *indexPath in pathes) {
NSLog(@"indexPath in pathes is %ld",(long)indexPath.row);
AVMSMCell *cell = (AVMSMCell *)[sortMediaCollection cellForItemAtIndexPath:indexPath];
AVMDataStore *oneItem = [smArray objectAtIndex:indexPath.row];
NSString *contentId = oneItem.fileId;
if (i<selectedPhotosURL.count){
NSLog(@"indexPath second loop is %ld",(long)indexPath.row);
[self deleteUserPhotos:contentId : indexPath.row : cell]; // send request to the server it's ok too.
i++;
}
}
} else {
[self selectAtLeastOneFirst];
}
}
For example here I select 6 cells and my array sort with right order from up to down (5,4,3,2,1,0). Then I pass this elements in method with this order.
Request send method:
-(void)deleteUserPhotos : (NSString *)contentId : (NSInteger )pathRow : (AVMSMCell *) cell{
NSNumber *rowNsNum = [NSNumber numberWithUnsignedInt:(unsigned int)pathRow];
if (([selecedCellsArray containsObject:[NSString stringWithFormat:@"%@",rowNsNum]]) )
{
cell.selectedBG.backgroundColor = DANGER;
[[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:YES];
AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
NSString *token = [defaults objectForKey:@"token"];
NSString *header = [NSString stringWithFormat:@"Bearer %@",token];
NSDictionary *params = @{@"lang": @"en",@"content_id":contentId,@"project_id":[defaults objectForKey:@"project_id"]};
manager.responseSerializer = [AFJSONResponseSerializer serializer];
[manager.requestSerializer setValue:header forHTTPHeaderField:@"Authorization"];
[manager POST:@"http://example.com/api/project/delete-content" parameters:params success:^(AFHTTPRequestOperation *operation, id responseObject) {
[[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];
NSLog(@"JSON: %@", responseObject);
if ([[responseObject objectForKey:@"result"] isEqualToString:@"success"]){
@try{
NSLog(@"pathRow in TRY %ld",(long)pathRow); // HERE I get wrong number after two or three elements already passed
[smArray removeObjectAtIndex:(unsigned int)pathRow];
[selecedCellsArray removeObject:[NSString stringWithFormat:@"%ld",(long)pathRow]];
cell.selectedBG.hidden = YES;
[sortMediaCollection reloadSections:[NSIndexSet indexSetWithIndex:0]];
loadCount--;
}
} @catch (NSException *e){
NSLog(@"something is bad %@",e);
[SVProgressHUD dismiss];
if (smArray.count<pathRow-1){
[smArray removeObjectAtIndex:(unsigned int)pathRow-1];
}
} @finally {
cell.selectedBG.hidden = YES;
[sortMediaCollection reloadSections:[NSIndexSet indexSetWithIndex:0]];
}
} else {
NSLog(@"can't delete photo!");
}
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
[[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];
NSLog(@"Error: %@", error);
errorEndSpinner
}];
}
}
So in method above I get wrong element number after two or three elements already passed i.e frist element is 5,then 4, then 2, 3,1,0.
And at this moment my @catch handle exception and trying to remove element with [smArray removeObjectAtIndex:(unsigned int)pathRow-1]; and then I get NSRangeException and my app crashing. What I do wrong?
I solved my problem with this answer and little bit modified my code.
I've got an NSRangeException because I removed my UICollectionView items through the loop. Instead I should better use multiple deleting instantly like this:
// Delete the items from the data source.
[self deleteItemsFromDataSourceAtIndexPaths:selectedItemsIndexPaths];
// Now delete the items from the collection view.
[sortMediaCollection deleteItemsAtIndexPaths:selectedItemsIndexPaths];
So now my code looks like:
Pass through the loop:
- (IBAction)deletePictures:(id)sender {
int i = 0;
if (selectedPhotosURL.count>0){
[SVProgressHUD showWithStatus:@"Deleting" maskType:SVProgressHUDMaskTypeBlack];
loadCount = (int)selectedPhotosURL.count;
NSArray *indexPaths = sortMediaCollection.indexPathsForSelectedItems;
NSMutableArray *pathes = [NSMutableArray arrayWithArray:indexPaths];
NSSortDescriptor *highestToLowest = [NSSortDescriptor sortDescriptorWithKey:@"self" ascending:NO];
[pathes sortUsingDescriptors:[NSArray arrayWithObject:highestToLowest]];
[selecedCellsArray sortUsingComparator:^NSComparisonResult(NSString *str1, NSString *str2) {
return [str2 compare:str1 options:(NSNumericSearch)];
}];
for(NSIndexPath *indexPath in pathes) {
AVMSMCell *cell = (AVMSMCell *)[sortMediaCollection cellForItemAtIndexPath:indexPath];
AVMDataStore *oneItem = [smArray objectAtIndex:indexPath.row];
NSString *contentId = oneItem.fileId;
if (i<selectedPhotosURL.count){
[self deleteUserPhotos:contentId : indexPath.row : cell pathes:pathes]; //pass array with pathes into 'deleteUserPhotos'
i++;
}
}
} else {
[self selectAtLeastOneFirst];
}
}
Main method:
-(void)deleteItemsFromDataSourceAtIndexPaths:(NSArray *)itemPaths {
NSMutableIndexSet *indexSet = [NSMutableIndexSet indexSet];
for (NSIndexPath *itemPath in itemPaths) {
[indexSet addIndex:itemPath.row];
}
[smArray removeObjectsAtIndexes:indexSet];
}
-(void)deleteUserPhotos : (NSString *)contentId : (NSInteger )pathRow : (AVMSMCell *) cell pathes:(NSMutableArray*)selectedItemsIndexPaths{
NSNumber *rowNsNum = [NSNumber numberWithUnsignedInt:(unsigned int)pathRow];
if (([selecedCellsArray containsObject:[NSString stringWithFormat:@"%@",rowNsNum]]))
{
cell.selectedBG.backgroundColor = DANGER;
[[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:YES];
AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
NSString *token = [defaults objectForKey:@"token"];
NSString *header = [NSString stringWithFormat:@"Bearer %@",token];
NSDictionary *params = @{@"lang": @"en",@"content_id":contentId,@"project_id":[defaults objectForKey:@"project_id"]};
manager.responseSerializer = [AFJSONResponseSerializer serializer];
[manager.requestSerializer setValue:header forHTTPHeaderField:@"Authorization"];
[manager POST:@"http://example.com/api/project/delete-content" parameters:params success:^(AFHTTPRequestOperation *operation, id responseObject) {
[[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];
NSLog(@"JSON: %@", responseObject);
if ([[responseObject objectForKey:@"result"] isEqualToString:@"success"]){
@try{
[selecedCellsArray removeObject:[NSString stringWithFormat:@"%ld",(long)pathRow]];
loadCount--;
if (loadCount==0){ //only there remove items from collectionview
// Delete the items from the data source.
[self deleteItemsFromDataSourceAtIndexPaths:selectedItemsIndexPaths];
// Now delete the items from the collection view.
[sortMediaCollection deleteItemsAtIndexPaths:selectedItemsIndexPaths];
[selectedPhotosURL removeAllObjects];
}
} @catch (NSException *e){
NSLog(@"something is bad %@",e);
[SVProgressHUD dismiss];
if (smArray.count<pathRow-1){
[smArray removeObjectAtIndex:(unsigned int)pathRow-1];
}
} @finally {
cell.selectedBG.hidden = YES;
[sortMediaCollection reloadSections:[NSIndexSet indexSetWithIndex:0]];
}
} else {
NSLog(@"can't delete photo!");
}
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
[[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];
NSLog(@"Error: %@", error);
errorEndSpinner
}];
}
}
Hope this will be helpful for somebody.