Add Distance from current location to NSMutableArray

Question

I'm trying to load the distance from my current location into my Array, but I seem to be missing something. My TableView only shows "?", which should only show if my currentLoc is not working, but my NSLog is showing the correct location. Please help

Update: Must have deleted my reload tableView, fixed the "?", but now I just get 0.00 km. Still missing something. My currentLoc is correct inside the LocationManager, but I lose it when I try to calculate the distance in my Array.

#import "AuthorViewController.h"
#import "Author.h"
#import <sqlite3.h>


@implementation AuthorViewController
@synthesize theauthors;
@synthesize currentLoc;

- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
currentLoc = newLocation;

if (newLocation.horizontalAccuracy <= 100.0f) {
    [locMgr stopUpdatingLocation];
}
NSLog(@"Lat: %f, Long: %f", currentLoc.coordinate.latitude, currentLoc.coordinate.longitude);

[self.tableView reloadData];
}

- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
{
NSString *msg = [[NSString alloc]initWithString:@"Error obtaining location"];
UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"Error" message:msg delegate:nil cancelButtonTitle:@"Done" otherButtonTitles:nil];
[alert show];
}


#pragma mark - View lifecycle

- (void)viewDidLoad
{
[self barList];
[super viewDidLoad];

NSLog(@"Lat2: %f, Long2: %f", currentLoc.coordinate.latitude, currentLoc.coordinate.longitude);
}

- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];

locMgr = [[CLLocationManager alloc] init];
locMgr.delegate = self;
[locMgr startUpdatingLocation];
}


#pragma mark - Table view data source

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{

// Return the number of rows in the section.
return [self.theauthors count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = @"Cell";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}
int rowCount = indexPath.row;

Author *author = [self.theauthors objectAtIndex:rowCount];



cell.textLabel.text = author.barName;

if (currentLoc == nil) {
    cell.detailTextLabel.text = [NSString stringWithFormat:@"?"];
}else
{
    cell.detailTextLabel.text = [NSString stringWithFormat:@"%.02f km", author.cachedDist];
}


return cell;
}


-(NSMutableArray *) barList{
theauthors = [[NSMutableArray alloc] init];
@try {
    NSFileManager *fileMgr = [NSFileManager defaultManager];
    NSString *dbPath = [[[NSBundle mainBundle] resourcePath ]stringByAppendingPathComponent:@"TulsaBars.sqlite"];
    BOOL success = [fileMgr fileExistsAtPath:dbPath];
    if(!success)
    {
        NSLog(@"Cannot locate database file '%@'.", dbPath);
    }
    if(!(sqlite3_open([dbPath UTF8String], &db) == SQLITE_OK))
    {
        NSLog(@"An error has occured: %@", sqlite3_errmsg(db));

    }


    const char *sql = "SELECT * FROM  TulsaBars";
    sqlite3_stmt *sqlStatement;
    if(sqlite3_prepare(db, sql, -1, &sqlStatement, NULL) != SQLITE_OK)
    {
        NSLog(@"Problem with prepare statement:  %@", sqlite3_errmsg(db));
    }else{

        while (sqlite3_step(sqlStatement)==SQLITE_ROW) {
            Author * author = [[Author alloc] init];
            author.barName = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement,1)];
            author.barAddress = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement,2)];
            author.barState = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement, 5)];
            author.barLat = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement, 8)];
            author.barLong = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement, 9)];
            author.cachedDist = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement, 10)];

            CLLocation *barLocation = [[CLLocation alloc] initWithLatitude:[author.barLat doubleValue] longitude:[author.barLong doubleValue]];
            CLLocationDistance distancekm = [currentLoc distanceFromLocation: barLocation]/1000;
            NSString *distanceString = [[NSString alloc] initWithFormat: @"%f", distancekm];
            author.cachedDist = distanceString;

            [theauthors addObject:author];
        }
    }
    sqlite3_finalize(sqlStatement);
}
@catch (NSException *exception) {
    NSLog(@"Problem with prepare statement:  %@", sqlite3_errmsg(db));
}
@finally {
    sqlite3_close(db);

    return theauthors;
}
}

@end

score 0 · Answer 1 · edited May 23 '17 at 12:12

0

Make sure to call [tableView reloadData] when you need to redraw the data in the table view.

You might also try the extended techniques outlined in this answer: What's the best way to refresh a UITableView within a UINavigationController hierarchy

edited May 23 '17 at 12:12

Community

1
1

answered Jun 28 '12 at 23:23

davidgoli

2,436
1
16
13

Thank you, I must have deleted my reload table somewhere. That solved the "?" problem, but now everything is just 0.00 km. – user1454340 Jun 28 '12 at 23:40
Is there a chance your currentLoc ivar is nil? – davidgoli Jun 29 '12 at 01:04
I think that is the problem, I'm just not seeing why. My NSLog for Lat and Long is showing correctly, but my NSLog for Lat2 and Long2 is showing 0 – user1454340 Jun 29 '12 at 01:21
has locationManager updated before rendering? If it has, have you called reloadData since the last update? – davidgoli Jun 29 '12 at 01:25
If it isn't I must be missing it. I think its actually in the way I'm loading the Array. – user1454340 Jun 29 '12 at 02:11

Add Distance from current location to NSMutableArray

1 Answers1