How to write XML files?

Question

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 n

Answer 1

Shameless self-promotion: KSXMLWriter

Answer 2

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.

Answer 3

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 4

Try the open source XML stream writer for iOS:

• Written in Objective-C, a single .h. and .m file
• One @protocol for namespace support and one for without

Example:

// allocate serializer
XMLWriter* xmlWriter = [[XMLWriter alloc]init];

// start writing XML elements
[xmlWriter writeStartElement:@"Root"];
[xmlWriter writeCharacters:@"Text content for root element"];
[xmlWriter writeEndElement];

// get the resulting XML string
NSString* xml = [xmlWriter toString];

This produces the following XML string:

<Root>Text content for root element</Root>