Convert network request from synchronous to asynchronous

[cityofangels]

I'm currently doing a synchronous network request to load my app which is not the best way as it blocks the UI. I'm also using ASIHTTPRequest. I understand I can just change the line from synchronous to asyncronous, but I think I need to setup a block so that I can trigger the table to reload once the async is completed.

The initial ViewController of my app:

    - (void)fetchAppointmentsForVisibleDate {
    	self.appointmentArray = [DrChronoDataSource getTodayData:self.visibleDate];
        
    	NSMutableArray *array = [NSMutableArray arrayWithCapacity:50];
    	for (NSDictionary *appointment in self.appointmentArray)
    	{
    		[array addObject: [NSString stringWithFormat:@"%@: %@", [appointment objectForKey:@"scheduled_time"], [appointment objectForKey:@"patient"]]];
    	}
    	self.listData = array;
        [self.appointmentTableView reloadData];
    }

In my app's dataSource class:

    + (NSMutableArray*)getTodayData:(NSDate*)today
    {
            NSURL *url = myURL here 
    		ASIFormDataRequest *request = [[ASIFormDataRequest alloc] initWithURL:url];
    		[request setPostValue:[dateFormat stringFromDate:today] forKey:@"target_date"];
    		
    		[request startSynchronous];
    		
    		NSError *error = [request error];
    		NSString *responseString;
    		if (!error) {
    			responseString = [request responseString];
    		} else {
    			return NULL;
    		}
            return [responseString JSONValue];
    }

[cityofangels]

I got this code but I'm getting a bunch of syntax errors, does anyone notice anything wrong? (ignore the pseudo code).

+ (void) getTodayData:(NSDate*)today callback:(void (^) (NSError * error, NSMutableArray * array)
{
        NSURL *url = myURL here 
        ASIFormDataRequest *request = [[ASIFormDataRequest alloc] initWithURL:url];
        [request setPostValue:[dateFormat stringFromDate:today] forKey:@"target_date"];
        [request setCompletionBlock:^{
            callback(nil, [responseString JSONValue]);
        }];
        [request setFailBlock:^{
           callback([request error], nil);
        ];
        [request startAsynchronous];
}

- (void)fetchAppointmentsForVisibleDate {
    [DrChronoDataSource getTodayData:self.visibleDate callback:^(NSError *error, NSMutableArray *data) {
        if (!error) {
            self.appointmentArray = [data retain];
            NSMutableArray *array = [NSMutableArray arrayWithCapacity:50];
            for (NSDictionary *appointment in self.appointmentArray)
            {
                [array addObject: [NSString stringWithFormat:@"%@: %@", [appointment objectForKey:@"scheduled_time"], [appointment objectForKey:@"patient"]]];
            }
            self.listData = array;
            [self.appointmentTableView reloadData];
        }
        else 
            NSLog(@"%@", error.description);
    }];
}

[Speed]

What are your errors?

Specifically when using ASIHTTPRequest and blocks, you should prefix ASIHTTPRequest with "__block" (same goes for ASIFormDataRequest), like so:

__block ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:[NSURL urlWithString:@"http://www.google.com"]];
[request setCompletionBlock:^{
    NSLog(@"%@",[request responseString]);
}];
[request startAsynchronous];