Segue Won't Set Data - ios

Question

I have a segue between MainViewController and BillTrackerViewController, both of which are UIViewController classes, but when i try to set a #property called event_name in BillTrackerViewController upon segue from MainViewController, the property remains null.
Because of this property, I am unable to use it to property query using Parse, as shown in the code below, and the app ends up crashing.
Code for MainViewController (segue name in question is "toBillTracker"):
#import "MenuViewController.h"
#import "AgendaViewController.h"
#import "BillTrackerViewController.h"
#import "ResearchViewController.h"
#import "Parse/Parse.h"
#interface MenuViewController ()
#end
#implementation MenuViewController {}
#synthesize event_name_label;
#synthesize event_name;
- (void)viewDidLoad
{
event_name_label.text = event_name;
[super viewDidLoad];
}
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
if([segue.identifier isEqualToString:#"toBillTracker"]) {
BillTrackerViewController *controller=(BillTrackerViewController *)segue.destinationViewController;
controller.event_name = event_name;
}
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
}
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
#end
And here is the code for BillTrackerViewController.m:
#import "BillTrackerViewController.h"
#import "Parse/Parse.h"
#interface BillTrackerViewController ()
#end
#implementation BillTrackerViewController
#synthesize billView;
#synthesize refreshButton;
#synthesize event_name;
#synthesize event_id;
#synthesize resolution_names;
#synthesize resolution_pro_speakers;
#synthesize resolution_con_speakers;
#synthesize resolution_results;
- (void)viewDidLoad
{
[super viewDidLoad];
}
- (IBAction)loadResolutions:(id)sender
{
resolution_names = [[NSMutableArray alloc] init];
resolution_pro_speakers = [[NSMutableArray alloc] init];
resolution_con_speakers = [[NSMutableArray alloc] init];
resolution_results = [[NSMutableArray alloc] init];
// Find event_id of the event
PFQuery *event_id_query = [PFQuery queryWithClassName:#"Event"];
[event_id_query whereKey:#"event_name" equalTo:event_name];
[event_id_query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (!error) {
for (PFObject *object in objects) {
event_id = object.objectId;
}
} else {
NSLog(#"Error: %# %#", error, [error userInfo]);
}
}];
// Now, use that event_id to locate all of its resolutions
PFQuery *resolution_query = [PFQuery queryWithClassName:#"Resolution"];
[resolution_query whereKey:#"event_id" equalTo:event_id];
[resolution_query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (!error) {
for (PFObject *object in objects) {
[resolution_names addObject:[object objectForKey:#"resolution_name"]];
// Sort resolutions in alphabetical order
resolution_names = (NSMutableArray*)[resolution_names sortedArrayUsingSelector:#selector(localizedCaseInsensitiveCompare:)];
}
// After sorting alphabetically, load other resolution data (pro speaker, result, etc.)
for (NSString *resolution_name in resolution_names) {
PFQuery *query = [PFQuery queryWithClassName:#"Resolution"];
[query whereKey:#"resolution_name" equalTo:resolution_name];
[query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
if (!error) {
for (PFObject *object in objects) {
[resolution_pro_speakers addObject:[object objectForKey:#"resolution_pro_speaker"]];
[resolution_con_speakers addObject:[object objectForKey:#"resolution_con_speaker"]];
switch ((int)[object objectForKey:#"resolution_result"]) {
case 0:
[resolution_results addObject:#"In Progress"];
case 1:
[resolution_results addObject:#"Passed"];
case 2:
[resolution_results addObject:#"Failed"];
case 3:
[resolution_results addObject:#"Passed with Amendment(s)"];
default:
[resolution_results addObject:#"In Progress"];
}
}
} else {
NSLog(#"Error: %# %#", error, [error userInfo]);
}
}];
}
} else {
NSLog(#"Error: %# %#", error, [error userInfo]);
}
}];
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
}
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) { }
return self;
}
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return [resolution_names count];
}
- (UITableViewCell *)tableView:(UITableView*)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"MainCell"];
if (cell == nil) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"MainCell"];
}
NSString *cellText = [NSString stringWithFormat:#"%#\nPro: %#\nCon: %#\nResult: %#",resolution_names[indexPath.row], resolution_pro_speakers[indexPath.row], resolution_con_speakers[indexPath.row], resolution_results[indexPath.row]];
cell.textLabel.text = cellText;
return cell;
}
#end
Thanks so much!