Calling a method from another class doesn't return - objective-c

Question

I'm using parse.com. I'm trying to display comments but in order to get the comments I have to get the PFObject from my DetailViewController but it doesn't return the PFObject to CommentsViewController
EDIT
here is all the code. I'm new to objective c so I'm probably doing something stupid
CommentsView Controller
#import "CommentsViewController.h"
#import "DetailViewController.h"
#import "CommentsCell.h"
#interface CommentsViewController (){
NSArray *commentsArray;
id commentInstance;
}
#end
#implementation CommentsViewController
- (id)init {
if (self = [super init]) {
[self performSelector:#selector(commentsQuery)];
}
return self;
}
- (void)commentsQuery {
commentInstance = [[DetailViewController alloc] init];
PFObject *tempObj = [commentInstance placeObject];
PFQuery *query1 = [PFQuery queryWithClassName:#"activity"];
[query1 whereKey:#"type" equalTo:#"comment"];
[query1 whereKey:#"place" equalTo:[NSString stringWithFormat:#"%#", [tempObj objectId]]];
NSLog(#"%#", tempObj);
[query1 orderByDescending:#"createdAt"];
[query1 findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (!error){
commentsArray = [[NSArray alloc]initWithArray:objects];
NSLog(#"%lu", (unsigned long)[commentsArray count]);
}
}];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return 1;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath;
{
static NSString *CellIdentifier = #"Cell";
CommentsCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
if (cell == nil) {
cell = [[CommentsCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
PFObject *placeObj = [commentInstance placeObject];
cell.username.text = #"test";
return cell;
}
#end
DetailsViewCOntroller
#import "DetailViewController.h"
#import "CommentsViewController.h"
#interface DetailViewController (){
CommentsViewController *test;
}
#end
#implementation DetailViewController
#synthesize place;
#synthesize userPhoto, message, username, checkCount, photo, scroller, commentsTableView;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
test = [[CommentsViewController alloc] init];
self.commentsTableView.delegate = test;
self.commentsTableView.dataSource = test;
//Adjust the message label box height
CGSize textSize = [[place objectForKey:#"message"] sizeWithFont:[UIFont systemFontOfSize:12] constrainedToSize:CGSizeMake(201, CGFLOAT_MAX) lineBreakMode: NSLineBreakByWordWrapping];
userPhoto.file = [place objectForKey:#"thumbnail"];
[userPhoto loadInBackground];
username.text = [place objectForKey:#"username"];
message.text = [place objectForKey:#"message"];
checkCount.text = [NSString stringWithFormat:#"%#", [place objectForKey:#"checkMarkCount"]];
[message sizeToFit];
if ([place objectForKey:#"photo"] != Nil){
photo.file = [place objectForKey:#"photo"];
[photo loadInBackground];
//[photo sizeToFit];
photo.frame = CGRectMake(6, textSize.height + 50, photo.frame.size.width, photo.frame.size.height);
float sizeOfContent = 0;
UIView *lLast = [scroller.subviews lastObject];
NSInteger wd = lLast.frame.origin.y;
NSInteger ht = lLast.frame.size.height;
NSLog(#"%#", lLast);
sizeOfContent = wd+ht;
scroller.contentSize = CGSizeMake(scroller.frame.size.width, sizeOfContent+100);
}
else{
float sizeOfContent = 0;
UIView *lLast = [scroller.subviews lastObject];
NSInteger wd = lLast.frame.origin.y;
NSInteger ht = lLast.frame.size.height;
NSLog(#"%#", lLast);
sizeOfContent = wd+ht;
scroller.contentSize = CGSizeMake(scroller.frame.size.width, sizeOfContent+100);
}
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (IBAction)checkMarkButton:(UIButton *)sender {
}
- (PFObject *)placeObject{
return place;
}
#end

Answer 1

I do not see where you allocate place object. You call init and then try retrieving place. It should return nil. Here is your code:
commentInstance = [[DetailViewController alloc] init];
PFObject *tempObj = [commentInstance placeObject];
commentInstance is a new object. There is no init function defined in DetailViewController, hence commentInstance.place is nil and that is returned by placeObject method.
You define place as a property
#property ... place
That gives you a member variable _pace and two member functions, place() and setPlace(place). The object itself is not allocated for you.
Allocate place object in your init function, get rid of placeObject(), replace it with object.place call.

Answer 2

I got rid of all that and in my DetailViewController I added [test placeSet:place] in my viewDidLoad method. Then in CommentsViewController I did...
- (void)placeSet:(PFObject *)object{
place = object;
NSLog(#"place = %#", place);
}