Question

I have a page that takes in a zip code from a user, sends that data to a php page, then retrieves the data via JSON. This page is throwing an error that says:

2011-12-27 15:17:49.919 BusinessManager[3595:20b] * Terminating app due to uncaught exception ‘NSInvalidArgumentException’, reason: ‘* -[NSConcreteData isFileURL]: unrecognized selector sent to instance 0x4751490′

The code is:

    - (id)initWithNibName:(NSString *)SearchZip bundle:(NSBundle *)nibBundleOrNil {
if (self = [super initWithNibName:SearchZip bundle:nibBundleOrNil]) {
    // Custom initialization
}
return self;
}


- (IBAction) searchzip: (id) sender
{
NSString *post =[NSString stringWithFormat:@"zipcode=%@",zipField.text];

NSString *hostStr =    @"https://www.mysite.com/searchzip.php?";
hostStr = [hostStr stringByAppendingString:post];
NSData *dataURL =  [NSData dataWithContentsOfURL: [ NSURL URLWithString: hostStr ]];

NSString *jsonData = [[NSString alloc] initWithContentsOfURL:dataURL];


self.zipArray = [jsonData JSONValue]; 

[jsonData release];
}
- (void)viewDidLoad {
[super viewDidLoad];

}



- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return 1;
}


- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return [zipArray count];
}


- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:  (NSIndexPath *)indexPath {
 NSDictionary *infoDictionary = [self.zipArray objectAtIndex:indexPath.row];
 static NSString *Prospects = @"agencyname";

 UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:Prospects];
 if (cell == nil) {
 cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:Prospects]  autorelease];
 }

 // setting the text
 cell.text = [infoDictionary objectForKey:@"agencyname"];   
 self.navigationItem.title = @"Zip Search";

 // Set up the cell
 return cell;

 }

Answer 1

You’re attempting to pass an instance of NSData into -initWithContentsOfURL: to create the jsonData instance of NSString.

I’m about to pimp your method. Notice that I’ve removed creating an NSData object altogether and renamed variables to be more clear.

- (IBAction)searchzip:(id)sender
{
    NSString *post = [NSString stringWithFormat:@"zipcode=%@", zipField.text];
    NSString *hostString = @"https://www.mysite.com/searchzip.php?";

    // Append string and add percent escapes
    hostString = [[hostString stringByAppendingString:post] stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
    NSURL *hostURL = [NSURL URLWithString:hostString];
    NSString *jsonString = [[NSString alloc] initWithContentsOfURL:hostURL];
    self.zipArray = [jsonString JSONValue]; 
    [jsonString release];
}