Problem: if you log out and sign up as new user - tableview of friends remain still, with friends of previous user!

#import "FriendsViewController.h"
#import "EditFriendsViewController.h"

@interface FriendsViewController ()

@end

@implementation FriendsViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.friendsRelation = [[PFUser currentUser] objectForKey:@"friendsRelation"];
}

-(void)viewWillAppear:(BOOL)animated{
    PFQuery* query = [self.friendsRelation query];
    [query orderByAscending:@"username"];
    [query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
        if (error) {
            NSLog(@"error: %@ %@",error,[error userInfo]);
        }else{
            self.friends = objects;
            [self.tableView reloadData];
        }
    }];
}

-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
    if ([segue.identifier isEqualToString:@"showEditFriends"]) {
        EditFriendsViewController* viewController = (EditFriendsViewController*)segue.destinationViewController;
        viewController.friends = [NSMutableArray arrayWithArray:self.friends];
    }
}

#pragma mark - Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    // Return the number of sections.
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    // Return the number of rows in the section.
    return self.friends.count;
}


- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"Cell"
                                                            forIndexPath:indexPath];

    PFUser* user = [self.friends objectAtIndex:indexPath.row];
    cell.textLabel.text = user.username;

    return cell;
}

@end