iphone - app crash in a form - ios

Question

In my app, I have a view where user have to fill a form. But, sometime the app crash here, in this function, that simple cacth the value field and built a url to give
-(NSString*)urlToUpload{
NSString *string1 =[[NSString alloc]init];
string1= [NSString stringWithFormat:#"?nombre="];
NSString *string2 = [string1 stringByAppendingString:nameAdded];
//crash here
NSString *string3 = [string2 stringByAppendingString:#"&horario="];
NSString *string4 = [string3 stringByAppendingString:horarioAdded];
NSString *string5 = [string4 stringByAppendingString:#"&info="];
NSString *string6 = [string5 stringByAppendingString:infoAdded];
NSString *string7 = [string6 stringByAppendingString:#"&offerta="];
NSString *string8 = [string7 stringByAppendingString:offertaAdded];
NSString *lat_string = [[[NSString alloc] initWithFormat:#"%f",locationToUpload2.latitude] autorelease];
NSString *lon_string = [[[NSString alloc] initWithFormat:#"%f",locationToUpload2.longitude] autorelease];
NSString *string9 = [string8 stringByAppendingString:#"&latitude="];
NSString *string10 = [string9 stringByAppendingString:lat_string];
NSString *string11 = [string10 stringByAppendingString:#"&longitude="];
NSString *string12 = [string11 stringByAppendingString:lon_string];
NSString *url1 = [NSString stringWithFormat:#"http://myserverside/mysql_up.php"];
NSString *url = [url1 stringByAppendingString:string12];
return url;
}
EDIT:
It seems problem appers on nameAdded when there is a white space into textField(i.e. MisterB not crash, Mister B yes ).
But I am using:
nameAdded =[[nameField.text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
and NSLOg give of nameAdded is Mister%20B.
The crash still appearing...

Answer 1

Just use a single stringWithFormat::
- (NSString *)urlToUpload {
NSString *url = [NSString stringWithFormat:#"http://myserverside/mysql_up.php?nombre=%#&horario=%#&info=%#&offerta=%#&latitude=%f&longitude=%f",
[nameAdded stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding],
[horarioAdded stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding],
[infoAdded stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding],
[offertaAdded stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding],
locationToUpload2.latitude, locationToUpload2.longitude];
return url;
}
Make sure the referenced variables are valid.
In your original code there is no need to alloc/init an NSString then assign another string to the same variable. That's a memory leak (string1).
If you really want to structure your code the way you have it, at least use an NSMutableString and append to that one mutable string. Creating over a dozen NSString variables is the wrong way to do it.
Updated: Ensure each of the strings added to the URL are properly escaped.

Answer 2

It looks like nameAdded may be the cause of your problems. Is it nil at that point?
Also
You are allocating a string, setting it to string1 and then immediately setting string1 to the class function stringWithFormat which allocates another string. Also you are using stringWithFormat but you aren't using any format so you could simply use NSString *string1 = #"?nombre=";
Rather than declaring all of those variables you should just use NSMutableString and build it all in one variabl