nsmutablearray elements to nsstring - objective-c

Question

I want to retrieve elements that are parsed in a NSMutableArray and store them into a NSString variable and then store them in NSMutableArray as NSString (because I want to display the content in a NSComboBox). I tried this but it dosen't work. Can you fix the problem, I can't fix it:
//--this is the parsing code :
- (void)parser:(NSXMLParser *)parser
didStartElement:(NSString *)elementName
namespaceURI:(NSString *)namespaceURI
qualifiedName:(NSString *)qualifiedName
attributes:(NSDictionary *)attributeDict {
if ([elementName isEqualToString:#"user"]) {
NSLog(#"user element found – create a new instance of User class...");
if(currentElementValue == nil)
currentElementValue = [NSMutableString string];
else
[currentElementValue setString:#""];
}
else {
currentElementValue = nil;
}
user = [[User alloc] init];
}
- (void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string {
if (!currentElementValue) {
// init the ad hoc string with the value
currentElementValue = [[NSMutableString alloc] initWithString:string];
} else {
// append value to the ad hoc string
[currentElementValue appendString:string];
if (currentElementValue)
{
currentElementValue = nil;
}
}
NSLog(#"Processing value for : %#", string);
}
- (void)parser:(NSXMLParser *)parser
didEndElement:(NSString *)elementName
namespaceURI:(NSString *)namespaceURI
qualifiedName:(NSString *)qName {
if ([elementName isEqualToString:#"users"]) {
// We reached the end of the XML document
return;
NSLog(#"QUIT");
}
if ([elementName isEqualToString:#"userName"]) {
[[self user] setUserName:currentElementValue];
NSLog(#"final step for value: %#", user.userName);
NSLog(#"currentElementName content : %#", currentElementValue);
[currentElementValue release];
NSLog(#"release : %#", currentElementValue);
currentElementValue = nil;
NSLog(#"release : %#", currentElementValue);
}
if ([elementName isEqualToString:#"firstName"]) {
[[self user] setFirstName:currentElementValue];
[currentElementValue release];
currentElementValue = nil;
}
if ([elementName isEqualToString:#"lastName"]) {
[[self user] setLastName:currentElementValue];
[currentElementValue release];
currentElementValue = nil;
}
if ([elementName isEqualToString:#"user"]) {
NSLog(#"\n user=%# \n",user);
[users addObject:user];
NSLog(#"userName test : %#", users);
[user release];
user = nil;
}
}
-(BOOL)parseDocumentWithData:(NSData *)data {
if (data == nil)
return NO;
NSXMLParser *xmlparser = [[NSXMLParser alloc] initWithData:data];
[xmlparser setDelegate:self];
[xmlparser setShouldResolveExternalEntities:NO];
BOOL ok = [xmlparser parse];
if (ok == NO)
NSLog(#"error");
else
NSLog(#"OK");
[xmlparser release];
return ok;
}
// this is the xml file :
<users>
<user>
<userName>mspeller</userName>
<firstName>Mike</firstName>
<lastName>Speller</lastName>
</user>
<user>
<userName>mgdan</userName>
<firstName>Mila</firstName>
<lastName>Gdan</lastName>
</user>
</users>
//-------
NSMutableArray *tabletest= [[NSMutableArray alloc] init];
NSMutableString * result = [[NSMutableString alloc] init];
int i;
for(i=0; i < [users count]; i++){
[result appendString:[NSString stringWithFormat:#"%#",[[users objectAtIndex:i] valueForKey:#"userName"]] ];
NSLog(#"result==%#",result);
[tabletest addObject:result];
}

Answer 1

Based on your link in the comment section I think you're accessing the "userName" property the wrong way. You're trying to access it, as users contains NSDictionary objects. As far as I can see you're adding User objects to the NSMutableArray.
Try the following (I took the liberty to beautify the code a bit):
NSMutableArray *tabletest= [NSMutableArray array];
for (User* user in users)
{
NSString* result = [NSString stringWithFormat:#"%#", user.userName];
NSLog(#"result==%#",result);
[tabletest addObject:result];
}
Please correct me if I totally misunderstood your design.

Answer 2

I don't follow what your intention is, but what your code does at the moment is add the same string [user count] time to the array tabletest as follows:
The line:
[result appendString:[NSString stringWithFormat:#"%#",[[users objectAtIndex:i] valueForKey:#"userName"]] ];
accumulates into result the result of appending each [[users objectAtIndex:i] valueForKey:#"userName"] together - each iteration of the loop adds the next item to the end of result.
The line:
[tabletest addObject:result];
Adds the object referenced by result into the array. This is done once per iteration so the array ends up with [users count] references to the same object. Placing a reference to a mutable string into an array does not place a copy of its current value, just a reference to the string - mutate the string and the mutation is visible through the reference stored in the array.
So the final result of your code is an array of [users count] references to the same mutable string, and that string is the concatenation of all the [[users objectAtIndex:i] valueForKey:#"userName"] values.
What was your intent?
If you are trying to create an array of string representations of [[users objectAtIndex:i] valueForKey:#"userName"] then change the code to:
NSMutableArray *tabletest= [[NSMutableArray alloc] init];
for(int i = 0; i < [users count]; i++)
{
// create a string representation of userName
NSString *result = [NSString stringWithFormat:#"%#",[[users objectAtIndex:i] objectForKey:#"userName"]];
// add the string to the array
[tabletest addObject:result];
}
But maybe your intent is something else?