[iPhone] How to write XML files?

Question

Hi.

I want to write a not so complicated but large file within my app and be able to send it by mail (using MFMailComposeViewController) Since NSXMLElement and related classes are not ported to iPhone SDK what options do I have for creating XML documents? Thanks in advance.

Answer 1

It's a homework exercise in NSString building. Abstractly, create a protocol like:

@protocol XmlExport
-(NSString*)xmlElementName;
-(NSString*)xmlElementData;
-(NSDictionary*)xmlAttributes;
-(NSString*)toXML;
-(NSArray*)xmlSubElements;
@end

Make sure everything you're saving implements it and build the XML with something like the following:

-(NSString*)toXML {
    NSMutableString *xmlString;
    NSString *returnString;

    /* Opening tag */
    xmlString = [[NSMutableString alloc] initWithFormat:@"<%@", [self xmlElementName]];
    for (NSString *type in [self xmlAttributes]) {
        [xmlString appendFormat:@" %@=\"%@\"", type, [[self xmlAttributes] valueForKey:type]];
    }   
    [xmlString appendString:@">"];

    /* Add subelements */
    for (id<XmlExport> *s in [self xmlSubElements]) {
        [xmlString appendString:[s toXML]];
    }

    /* Data */
    if ([self xmlElementData]) {
        [xmlString appendString:[self xmlElementData]];
    }

    /* Close it up */
    [xmlString appendFormat:@"</%@>", [self xmlElementName]];

    /* Return immutable, free temp memory */
    returnString = [NSString stringWithString:xmlString];
    [xmlString release]; xmlString = nil;

    return returnString;
}

Answer 2

KSXMLWriter

Answer 3

Try this

http://code.google.com/p/xswi/

for a simple XML writer.

Answer 4

I would recommend using KissXML. The author started in a similar situation as you and created an NSXML compatible API wrapper around libxml. He discusses the options and decisions here on his blog.