Core Data NSSet to fill tableview

[tazboy]

Basically I have an NSSet of students and I want their names property to populate a tableview. More info below.

I have a course object that I've passed through a few view controllers. This course object has properties of name, hour and an NSSet of students, whom all have a name property. For some reason I can't figure out how to populate a tableview with that set of students' names.

I've tried studentArray = [[course students] allObjects]; but that doesn't seem to work. I just really need to order the student names and then put them in a tableview. I just can't figure this out.

Any ideas?

Thanks.

[raphaelharboun]

if you used a NSFetchRequest to get your course object, it may have lost the reference to your object the time you use it in your view controller.
have you done a copy of this object after the request ? you should do.

Just put a breakpoint to see if your object is still filled with studends...

With it's right, fill an array with the students and sort it with a NSSortDescriptor.
NSArray *a= [course.students allObjects]
NSSortDescriptor *d = [[NSSortDesciptor alloc] initWithKey:@"name"];
a = [a sortedArrayUsingDescriptor:[NSArray arrayWithObject:d]];
[d release];

i wrote the code directly, the syntax may not be all right..
just try.
but start by checking with the debbuger the value of your course object.

[tazboy]

They are still there because when I put this code in viewDidLoad I get everything I expect.

NSLog(@"Course Hour: %@", course.hour);
NSLog(@"Course Name: %@", course.name);
NSLog(@"Students are: ");
for (Student *aStudent in course.students) 
      NSLog(aStudent.name);

[raphaelharboun]

So have you tried the code i gave you ?

Could you give the entire code of your view controller, the problem may come from an other method.

[tazboy]

I tried your code. Here is the working code.

NSArray *a= [course.students allObjects];
NSSortDescriptor *d = [[NSSortDescriptor alloc] initWithKey:@"name" 
    ascending:YES];
a = [a sortedArrayUsingDescriptors:[NSArray arrayWithObject:d]];
[d release];

I believe the issue with your code is that it doesn't get the names of the students. NSArray *a seems to be holding an array of student objects.

Here is the output when I do
NSLog(@"Students' names are: %@", [a componentsJoinedByString:@", "]);

2010-07-10 18:31:38.572 PickEm[7715:20b] Students' names are: <Student: 0xf5a120> (entity: Student; id: 0xf59f60 <x-coredata://E4C16B60-53CA-46C2-990E-0AF6151DAA34/Student/p2> ; data: {
    course = 0xf3a7e0 <x-coredata://E4C16B60-53CA-46C2-990E-0AF6151DAA34/Course/p1>;
    name = Billy;
    weight = 2;
}), <Student: 0xf5a1a0> (entity: Student; id: 0xf4d520 <x-coredata://E4C16B60-53CA-46C2-990E-0AF6151DAA34/Student/p4> ; data: {
    course = 0xf3a7e0 <x-coredata://E4C16B60-53CA-46C2-990E-0AF6151DAA34/Course/p1>;
    name = George;
    weight = 2;

For now, all I need to do is the tableView:cellForRowAtIndexPath: method and set the cell.textLabel.text to the names of the students.

[raphaelharboun]

lol, it looks fine to me
The NSArray now contains all the student objects you required, you just have to get the property you want => the name.
now you can set the cell atributes with the content of the object.
cell.textLabel.text = [[a objectAtIndex:indexPath.row] name];

If you want to make a core data request which give you only one property of an object, you should check the NSExpression class.

But with what i just gave you, it should works fine.