xcode uitableview - xcode

Question

i have an array of objects which i am populating in a UItable one of my attributes of each object is a YES/NO value
Im using the- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { to populate my table as follows .
My code creates a table entry for each object in the array. I would like to only populate the table using objects in the array which have the "display" attribute set to YES? how do i do this?
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *cellidentifier = #"customcell";
customcell *cell = (customcell *)[tableView dequeueReusableCellWithIdentifier:
cellidentifier];
my_details *myObj = [appDelegate.myArray objectAtIndex:indexPath.row];
// UITableViewCell cell needs creating for this UITableView row.
if (cell == nil)
{
NSArray *topLevelObjects = [[NSBundle mainBundle] loadNibNamed:#"customcell" owner:self options:nil];
for (id currentObject in topLevelObjects) {
if ([currentObject isKindOfClass:[customcell class]]) {
cell = (customcell *) currentObject;
break;
}
}
}
cell.line1.text = myObj.line1;
cell.line2.text = myObj.line2;
cell.line3.text = myObj.line3;
return cell;
}

Answer 1

It would be a good idea to try to filter the objects before sending them to the table for display.
You could use an NSPredicate to filter the array of objects and when an object changes it's state, the display attribute is set to yes, refilter the array and pass it to the tableview.
NSPredicate *testForTrue = [NSPredicate predicateWithFormat:#"display == YES"];
NSArray *filteredArray = [myObjectsArray filteredArrayUsingPredicate:testForTrue];
after you obtain the filteredArray you need to pass it to the tableView and tell it to reload it's data in order to refresh.

Answer 2

As #Sorin indicates you have to filter your table. This can be done before or during the insertion in the table. Which one is a matter of taste (and which guidelines you normally follow for programming)
a) Before
Have all data -> filter -> Have reduced set -> Display reduced table
b) During
Have all data -> count #items -> introduce in rows -> Display table
For that you have to adapt numberOfRowsInSection (pseudo code!)
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
counter=0;
for each in table
if value = YES counter++
return counter;
}
In the cellForRowAtIndexPath you now have to keep track of the next line to insert, via a global variable: (pseudo code!)
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell;
static NSString *CellIdentifier = #"Cell";
cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
rowcounter++;
cell.textLabel.text=[selectionTableArray objectAtIndex:rowcounter];
return cell;
}