IOS set and get property on load - ios

Question

I'm trying to initialize a couple properties fetched from parse.com when the view is loaded so I can do calculation with them. For instance, I declare the following in my header file:
TaskViewController.h
#property (nonatomic, assign) int taskTotalCount;
#property (nonatomic, assign) int taskCompletedCount;
#property (nonatomic, assign) int progressCount;
- (void)CountAndSetTotalTask;
- (void)CountAndSetCompletedCount;
- (void)CalculateProgress;
Then in the implementation, assuming all the other initialization are setup properly and they are called in viewdidload, below are the method implementations:
TaskViewController.m
- (void)CountAndSetCompletedCount {
// Query the tasks objects that are marked completed and count them
PFQuery *query = [PFQuery queryWithClassName:self.parseClassName];
[query whereKey:#"Goal" equalTo:self.tasks];
[query whereKey:#"completed" equalTo:[NSNumber numberWithBool:YES]];
[query countObjectsInBackgroundWithBlock:^(int count, NSError *error) {
if (!error) {
// The count request succeeded. Assign it to taskCompletedCount
self.taskCompletedCount = count;
NSLog(#"total completed tasks for this goal = %d", self.taskCompletedCount);
} else {
NSLog(#"Fail to retrieve task count");
}
}];
}
- (void)CountAndSetTotalTask {
// Count the number of total tasks for this goal
PFQuery *query = [PFQuery queryWithClassName:self.parseClassName];
[query whereKey:#"Goal" equalTo:self.tasks];
[query countObjectsInBackgroundWithBlock:^(int count, NSError *error) {
if (!error) {
// The count request succeeded. Assign it to taskTotalCount
self.taskTotalCount = count;
NSLog(#"total tasks for this goal = %d", self.taskTotalCount);
} else {
NSLog(#"Fail to retrieve task count");
}
}];
}
- (void)CalculateProgress {
int x = self.taskCompletedCount;
int y = self.taskTotalCount;
NSLog(#"the x value is %d", self.taskCompletedCount);
NSLog(#"the y value is %d", self.taskTotalCount);
if (!y==0) {
self.progressCount = ceil(x/y);
} else {
NSLog(#"one number is 0");
}
NSLog(#"The progress count is = %d", self.progressCount);
}
The issue I am encountering is that the taskTotalCount and taskCompletedCount are set correctly and returns different numbers in the first two methods while the NSLog returns 0 for both x and y. Therefore I'm not sure if the third method somehow got loaded before the two properties are set or it's some other issues. Thank you in advance for any pointers.

Answer 1

Assuming you call these three methods like this:
- (void)viewDidLoad {
[super viewDidLoad];
[self CountAndSetCompletedCount];
[self CountAndSetTotalTask];
[self CalculateProgress];
}
then the problem is that the first two methods return immediately while the calls to Parse occur in the background. This means that CalculateProgress is called long before you get back the results from the calls to Parse.
One solution is to just call CountAndSetCompletedCount from viewDidLoad. In its completion handler you then call CountAndSetTotalTask. In its completion handler you finally call CalculateProgress.