Downloading JSON in iOS and using it to draw the UI - ios

Question

I'm relatively new to iOS development and my current project requires me to Connect to a website through a Rest API, and use JSON Objects received from the site to populate a Custom UITableViewController which I have implemented. I have been able to download the information and get it to display on the table properly, but this requires me to enter the page which starts the download, then leave the page and enter it again, upon which all of the cells are populated. How can I make my app load this information without leaving the page?
My Custom UITableViewClass contains the following methods:
- (void)viewDidLoad {
[super viewDidLoad];
NSString *chuckFranklinConnection = #"http://chuckfranklinlaw.com/wp-json/posts?type=tribe_events";
NSURLSession *session = [NSURLSession sharedSession];
[[session dataTaskWithURL: [NSURL URLWithString:chuckFranklinConnection]
completionHandler:^(NSData *data,
NSURLResponse *response,
NSError *error){
//Complete Data Handling from Chuckfranklinlaw.com Here
NSString *responseData = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
NSError *e = nil;
jsonArray = [NSJSONSerialization JSONObjectWithData: data options:NSJSONReadingMutableContainers error: &e];
if(!jsonArray) {
NSLog(#"Error parsing JSON: %#", e);
}else {
NSLog(#"Begin Successful Parse Readout -----------");
for(NSDictionary *item in jsonArray) {
NSLog(#"Item: %#", item);
}
}
}]
resume];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
//UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:<##"reuseIdentifier"#> forIndexPath:indexPath];
// Configure the cell...
EventTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:#"EventsCell"];
if(cell == nil) {
cell = [[EventTableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:#"EventsCell"];
cell.selectionStyle = UITableViewCellSelectionStyleNone;
}
//Formatting for each Cell Title
cell.textLabel.lineBreakMode = NSLineBreakByWordWrapping;
cell.textLabel.numberOfLines = 0;
cell.textLabel.text = [[jsonArray objectAtIndex:indexPath.row] objectForKey: #"title"];
//Formatting for each Cell Detail
NSString *startDate = [[jsonArray objectAtIndex:indexPath.row] objectForKey: #"StartDate"];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:#"yyyy-MM-dd HH:mm:ss"];
NSDate *date = [dateFormatter dateFromString:startDate];
[dateFormatter setDateStyle:NSDateFormatterMediumStyle];
[dateFormatter setTimeStyle:NSDateFormatterShortStyle];
cell.data = [[jsonArray objectAtIndex:indexPath.row] objectForKey:#"ID"];
cell.detailTextLabel.text = [dateFormatter stringFromDate:date];
//Work On Implementing Image View for App in this section
NSDictionary *imageInfo = [[jsonArray objectAtIndex:indexPath.row] objectForKey:#"featured_image"];
NSDictionary *attachmentMeta = [imageInfo objectForKey:#"attachment_meta"];
NSDictionary *sizes = [attachmentMeta objectForKey:#"sizes"];
NSDictionary *thumbnail = [sizes objectForKey:#"thumbnail"];
NSString *url = [thumbnail objectForKey:#"url"];
NSLog(url);
UIImage* image = [UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:url]]];
cell.imageView.image = image;
return cell;
[cell setNeedsDisplay];
}
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
if([segue.identifier isEqualToString:#"showEventDetail"])
{
NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];
DetailViewController *detailView = segue.destinationViewController;
NSString *contentString = [[jsonArray objectAtIndex:indexPath.row] objectForKey:#"content"];
//The Following code mutates the HTML Strings recieved from the server into NSStrings for displaying
contentString = [contentString stringByReplacingOccurrencesOfString:#"’" withString:#"\'"];
contentString = [contentString stringByReplacingOccurrencesOfString:#"<p>" withString:#""];
contentString = [contentString stringByReplacingOccurrencesOfString:#"</p>" withString:#"\n"];
detailView.content = contentString;
detailView.title = [[jsonArray objectAtIndex:indexPath.row] objectForKey:#"title"];
NSString *startDate = [[jsonArray objectAtIndex:indexPath.row] objectForKey:#"StartDate"];
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:#"yyyy-MM-dd HH:mm:ss"];
NSDate *date = [dateFormatter dateFromString:startDate];
[dateFormatter setDateStyle:NSDateFormatterMediumStyle];
[dateFormatter setTimeStyle:NSDateFormatterShortStyle];
detailView.eventTime = [dateFormatter stringFromDate:date];
//Pull Image from web and serve to next page
NSDictionary *imageInfo = [[jsonArray objectAtIndex:indexPath.row] objectForKey:#"featured_image"];
NSDictionary *attachmentMeta = [imageInfo objectForKey:#"attachment_meta"];
NSDictionary *sizes = [attachmentMeta objectForKey:#"sizes"];
NSDictionary *blogFull = [sizes objectForKey:#"blog-full"];
NSString *url = [blogFull objectForKey:#"url"];
detailView.image = [UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:url]]];
}
}

Answer 1

In your completion block: [self.tableview reloadData]. Documentation.
Actually, you will want to create a weak reference to self, then use the weak reference in your completion block.