Problems parsing XML using NSXMLParser

Question

I'm having strange problems parsing (apparently) correct XML code!

The xml parsed is:

<?xml version="1.0" encoding="UTF-8" ?>
<root>
<results>
<file id="0" name="   Linux Ubuntu.rar                                                                  700.64     2" size="700" disp="2"/>
<file id="1" name="   [Soft] Sistema operativo Linux. Live CD Distro Ubuntu-5.04-live-i386.iso          624.926     4" size="5" disp="4"/>
<file id="2" name="   ubuntu-9.04-server-i386.iso                                                       577.220     2" size="9" disp="2"/>
<file id="3" name="   virtualbox-3.1_3.1.2-56127_Ubuntu_karmic_amd64.deb                                 43.578     1" size="3" disp="1"/>
<file id="4" name="   [APP-ITA].UBUNTU.LINUX.iso                                                        586.822     2" size="586" disp="2"/>
<file id="5" name="   Ubuntu linux 2007.iso                                                             700.446     1" size="700" disp="1"/>
<file id="6" name="   Installare aMule Adunanza + Liste Server + Liste Nodi su Ubuntu Gutsy [Fastweb      0.72     5" size="0" disp="5"/>
<file id="7" name="   - Guida Per Linux Ubuntu 7.03 Facile Da Usare!!!!!!!La Prima In Ita.rar           731.351     3" size="7" disp="3"/>
<file id="8" name="   Ubuntu Hacks - Tips and Tools for Exploring, Using, and Tuning Linux (O'Reilly,     3.494     1" size="3" disp="1"/>
<file id="9" name="   Linux-ubuntu-8.04.1-desktop-i386.iso                                              694.498     3" size="8" disp="3"/>
<file id="10" name="   [MANUALE] Ubuntu Linux - Computer Magazine.pdf                                     86.992     2" size="86" disp="2"/>
<file id="11" name="   (Ebook - Ita - Software) Ubuntu - Desktop Guide.pdf                                 0.686     3" size="0" disp="3"/>
<file id="12" name="   Installare Amule Adunanza In Ubuntu.rar                                             0.25     6" size="0" disp="6"/>
<file id="13" name="   UBUNTU LINUX [ITA].PDF                                                              0.536     62" size="0" disp="62"/>
<file id="14" name="   Comandi Fondamentali Ubuntu.rtf                                                     0.67     4" size="0" disp="4"/>
<file id="15" name="   ubuntu Guida.tar                                                                    0.160     1" size="0" disp="1"/>
<file id="16" name="   ubuntu-remix-italiano-8.10.iso                                                    702.720     1" size="8" disp="1"/>
</results>
</root>

NSXMLParser gives me the following error:

2010-01-13 20:23:22.500 iMule[1419:20b] Error 65, Description: (null), Line: 13, Column: 24
2010-01-13 20:23:22.516 iMule[1419:20b] Error 4, Description: (null), Line: 1, Column: 1

The funny thing is that, if i parse these lines singularly i have no problems, the parser dosent fuss at all!

My parsing code is:

    // DELEGATE XML PARSER

- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName     namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qualifiedName   attributes:(NSDictionary *)attributeDict{
    if([elementName isEqualToString:@"downloads"] || [elementName isEqualToString:@"results"]){
    NSLog(@"starting or downloads or results");
    if(xmlArray){
        xmlArray= nil;
    }
    self.xmlArray= [[NSMutableArray alloc] init];
    if([elementName isEqualToString:@"results"]){
        [self.results_controller.activity startAnimating];
    }
    if([elementName isEqualToString:@"downloads"]){
        [self.downloads_Controller.activity startAnimating];
    }
}
else if([elementName isEqualToString:@"file"]){
    NSLog(@"found file...");
    [self.xmlArray addObject:attributeDict];
}
}

 - (void)parser:(NSXMLParser *)parser didEndElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName{
NSLog(elementName);
if([elementName isEqualToString:@"downloads"] || [elementName isEqualToString:@"results"]){
    if([elementName isEqualToString:@"downloads"]){
        NSLog(@"downloads found...  reloading table");
        self.downloads_Controller.downloads= xmlArray;
        [self.downloads_Controller.tableView reloadData];
        [self.downloads_Controller.activity stopAnimating];
    }
    else if([elementName isEqualToString:@"results"]){
        NSLog(@"results found... reloading table");
        self.results_controller.results= xmlArray;
//          NSLog(@"xmlarray: %@ and results: %@", xmlArray, self.results_controller.results);
        [self.results_controller.tableView reloadData];
        [self.results_controller.activity stopAnimating];
    }
}
else if([elementName isEqualToString:@"error"]){
    UIAlertView *alert= [[UIAlertView alloc] initWithTitle:@"Error" message:@"aMule dosent seem to be on" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
    [alert show];
    [alert release];
}
}

- (void)parser:(NSXMLParser *)parser parseErrorOccurred:(NSError *)parseError{
NSLog(@"Error %i, Description: %@, Line: %i, Column: %i", [parseError code],
      [[parser parserError] localizedDescription], [parser lineNumber],
      [parser columnNumber]);
 }

- (void)parser:(NSXMLParser *)parser validationErrorOccurred:(NSError *)validError{
NSLog(@"valid: %@", validError);
}


// END DELEGATES XML PARSER

Does someone have a clue of what it could be?

Thanks

Answer 1

When you say "parse these lines singularly" do you mean you handed it a complete XML document with only a single "file" entry? If that's the case, then another approach would be to set up the XML document with two "file" entries, one with file 0 and file 1, one with file 1 and file 2, one with file 2 and file3, etc., and see if all pairs work correctly. Depending on how you're passing the XML into the parser, you may have a problem that only shows up when parsing successive file entries.

Depending on how long your parsing code is, it would be helpful for you to add it to the original post.

This short program parses your supplied data just fine with NSXMLParser:

#import <Foundation/Foundation.h>


int
main()
{
    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];

NSData *xml = [NSData dataWithContentsOfFile: @"data.xml"];
NSLog(@"xml: %@", [[NSString alloc] initWithData: xml encoding: NSASCIIStringEncoding]);

NSXMLParser *parser = [[NSXMLParser alloc] initWithData: xml];
if (!parser)
    NSLog(@"Unable to initialize parser");
else if ([parser parse])
    NSLog(@"Parsed successfully");
else
    NSLog(@"Parsing failed: %@", [[parser parserError] localizedDescription]);

[pool release];
return 0;


}

Answer 2

Did you look up the error codes?

• NSXMLParserSpaceRequiredError= 65,
• NSXMLParserInternalError= 1,

Looks like the XML parser thinks some space is required at the 24th column of the 13th line.

Could you post the XML data on a pastebin so we can look at the raw data? I suspect that either you or Stack Overflow changed the data in some way (perhaps for formatting reasons) and this threw off the line/column numbers from what NSXMLParser is reporting.