Autocomplete text field in iOS not working - ios

Question

i am newbie in iOS development, i want to add autocomplete textfield in my ap i write a code for that like as
- (void)viewDidLoad
{
[self get data];
}
-(void)getdata
{
NSMutableArray *allObjects = [NSMutableArray array];
NSUInteger limit = 1000;
__block NSUInteger skip = 0;
PFQuery *query = [PFQuery queryWithClassName:#"MapInfo"];
[query setLimit: limit];
[query setSkip: skip];
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (!error) {
[allObjects addObjectsFromArray:objects];
if (objects.count == limit) {
skip += limit;
[query setSkip: skip];
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
[allObjects addObjectsFromArray:objects];
self.qpinname=[allObjects valueForKey:#"GPIN"];
self.locationarray=[allObjects valueForKey:#"Location"];
self.latitude=[self.locationarray valueForKey:#"lat"];
self.longitude=[self.locationarray valueForKey:#"lng"];
self.address=[allObjects valueForKey:#"Address"];
NSLog(#"Address %#",self.address);
self.usernameArray=[allObjects valueForKey:#"AddedBy"];
}];
}
}
else
{
NSLog(#"Error: %# %#", error, [error userInfo]);
}
}];
}
then i got my data array and i want to show it on my table view like as
- (void)searchAutocompleteEntriesWithSubstring:(NSString *)substring
{
[self.autoaddress removeAllObjects];
for(NSString *curString in self.address)
{
NSRange substringRange = [curString rangeOfString:substring];
if (substringRange.location == 0) {
[self.autoaddress addObject:curString];
}
}
[_autocompleteTableView reloadData];
}
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
_autocompleteTableView.hidden = NO;
NSString *substring = [NSString stringWithString:textField.text];
substring = [substring stringByReplacingCharactersInRange:range withString:string];
[self searchAutocompleteEntriesWithSubstring:substring];
return YES;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger) section
{
return self.autoaddress.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = nil;
static NSString *AutoCompleteRowIdentifier = #"AutoCompleteRowIdentifier";
cell = [tableView dequeueReusableCellWithIdentifier:AutoCompleteRowIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc]
initWithStyle:UITableViewCellStyleDefault reuseIdentifier:AutoCompleteRowIdentifier] ;
}
cell.textLabel.text = [self.autoaddress objectAtIndex:indexPath.row];
return cell;
}
then i got error in code
- (void)searchAutocompleteEntriesWithSubstring:(NSString *)substring
{
[self.autoaddress removeAllObjects];
for(NSString *curString in self.address)
{
NSRange substringRange = [curString rangeOfString:substring];
if (substringRange.location == 0) {
[self.autoaddress addObject:curString];
}
}
[_autocompleteTableView reloadData];
}
Here i got error in line NSRange substringRange = [curString rangeOfString:substring]; -[NSNull rangeOfString:]: unrecognized selector sent to instance i find it in google but i not get solution please help me for this
thanks.

Answer 1

Your self.address property is probably NSNull or it contains NSNull if it is an array. You can check if object is NSNull the following way:
if(![object isEqual:[NSNull null]])
{
//do something if object is not equals to [NSNull null]
}
The code is from this answer.
EDIT: If you use NSMutableArray you can call the method [self.address removeObjectIdenticalTo:[NSNull null]] to remove all NSNull objects from the array after self.address=[allObjects valueForKey:#"Address"];