Filter Tableview - ios

Question

How to filter tableview based on a picker value?
I have the following NSMutableArray:
[0]:Object 1 (name1, October)
[1]:Object 2 (name2, November)
[2]:Object 3 (name3, March)
[3]:Object 4 (name4, April)
[4]:Object 5 (name5, April)
The table view displays the value of these objects.
and I have a picker with month values (January, February,... etc)
so based on the user selection of picker value, the table view should display values for example if I choose month April, only these values object 3 and 4 should appear.
Solution code, thanks to Fennelouski: (just thought I'd put it here In case someone needs it)
NSMutableArray *array;
NSMutableArray *filteredArray;
int monthInt;
NSString *monthString;
#implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
Titles *object1 = [[Titles alloc]init];
[object1 setTitle:#"Title1"];
[object1 setMonth:#"10"];
Titles *object2 = [[Titles alloc]init];
object2.title = #"Title2";
object2.month = #"10";
Titles *object3 = [[Titles alloc]init];
object3.title = #"Title3";
object3.month = #"4";
array = [[NSMutableArray alloc]init];
filteredArray = [[NSMutableArray alloc]init];
[array addObject:object1];
[array addObject:object2];
[array addObject:object3];
pickerData = #[#"Jan", #"Feb", #"March", #"April", #"May", #"June", #"July", #"Aug", #"Sept", #"October", #"Nov", #"Dec"];
NSDate *currentDate = [NSDate date];
NSCalendar* calendar = [NSCalendar currentCalendar];
NSDateComponents* components = [calendar components:NSYearCalendarUnit|NSMonthCalendarUnit|NSDayCalendarUnit fromDate:currentDate];
monthInt= [components month];
monthString = [NSString stringWithFormat:#"%li",(long)monthInt];
for (Titles *item in array)
{
if([item.month isEqualToString:monthString])
{
[filteredArray addObject:item];
}
}
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return [filteredArray count];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *simpleTableIdentifier = #"SimpleTableItem";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:simpleTableIdentifier];
}
Titles *titles = filteredArray[indexPath.row];
cell.textLabel.text = titles.title;
cell.imageView.image = [UIImage imageNamed:#"totoro.jpg"];
NSLog(#"Cell is %#", [array objectAtIndex:indexPath.row]);
return cell;
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (int)numberOfComponentsInPickerView:(UIPickerView *)pickerView
{
return 1;
}
// The number of rows of data
- (int)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
{
return pickerData.count;
}
// The data to return for the row and component (column) that's being passed in
- (NSString*)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
{
return pickerData[row];
}
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
NSLog(#"Row: %li", (long)row);
monthString = [NSString stringWithFormat:#"%li",row+1];
[filteredArray removeAllObjects];
for (Titles *item in array)
{
if([item.month isEqualToString:monthString])
{
[filteredArray addObject:item];
}
}
[self.tableview reloadData];
}

Answer 1

It seems like you're following the design pattern of having your table view represent information stored in a separate data structure. That's good and makes filtering much easier.
Fortunately, you don't have to really do much with the table view to filter the results. All you need to do is filter the data structure that your table view is reading from and then update the table view.
I'd recommend adding an array in between your mutable array and the table view.
Something like this should work well for you
NSMutableArray *filteredObjects = [NSMutableArray new];
for (MYObjectClass *object in myMutableArray) {
if ([object.stringProperty isEqualToString:#"Filter"]) {
[filteredObjects addObject:object];
}
}
Then have your table view reference filteredObjects rather than the array you're using that has all of your data.