无法使用NSXML Parser进行解析

Question

I have the following XML file :

<?xml version="1.0"? encoding="UTF-8"?>
<api>
        <count count="55" />
        <spa>
            <opt>aa</opt>
            <opt>bb</opt>
            <opt>cc</opt>

        </spa>
</api>

M using the following lines of code :

NSString *path = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"space.xml"];

NSData *data = [[NSData alloc] initWithContentsOfFile:path];

NSXMLParser *xmlParser = [[NSXMLParser alloc] initWithData:data];

//Initialize the delegate.
XMLParser *theParser = [[XMLParser alloc] initXMLParser];

//Set delegate
[xmlParser setDelegate:theParser];

//Start parsing the XML file.
BOOL success = [xmlParser parse];

if(success)
    NSLog(@"No Errors");
else
    NSLog(@"Error Error Error!!!");

However, m getting the output as "error error error" in gdb. I am new to Objective C and unable to get through the error. Can someone please help ?? Thanks.

Answer 1

// Try to use NSXMLParser

NSXMLParser *parser = [[NSXMLParser alloc]initWithContentsOfURL:[NSURL URLWithString:@"YourURL"]];
[parser setDelegate:self];
[parser parse];

// Below are the delegates which will get you the Data

-(void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict

  {    
            if([elementName isEqualToString:@"spa"]){
           got = YES; //got is a BOOL and here we have encountere start tag i.e <spa>
     }
  }

    -(void)parser:(NSXMLParser *)parser foundCharacters:(NSString *)string
     {
          if(got)
          {
                 NSLog(@"the Data is = %@",string);
          }
     }

    -(void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName
     {
         if([elementName isEqualToString:@"spa"])
        {
           got = NO; //Here we have encountered the end tag </spa>
        }

     }

Answer 2

Have you checked if ' path ' or ' data ' are nil?

Also, if 'parse' didn't succeed, you can use the method ' parserError ' to get an NSError object that will hold more information about the problem. From NSXMLParser class reference:

parserError
Returns an NSError object from which you can obtain information about a parsing error.

 - (NSError *)parserError 

Discussion
You may invoke this method after a parsing operation abnormally terminates to determine the cause of error.

Availability
Available in iOS 2.0 and later.

After this, you should be able to call the method ' localizedDescription ' on your NSError* object to get more information about the problem.

I hope this helps!