Objective-C

XML Document References

See more XML Examples

This example demonstrates the fact that the entire XML document remains in memory if at least one node is referenced. (It does not need to be the root node.) Objective-C

#import <CkoXml.h>

BOOL success = NO;

CkoXml *xml = [[CkoXml alloc] init];

success = [xml LoadXml: @"<a><b>BBB</b><c>CCC</c></a>"];

NSLog(@"%@",[xml GetXml]);

// We have the following XML stored in memory:

// 	<?xml version="1.0" encoding="utf-8"?>
// 	<a>
// 	    <b>BBB</b>
// 	    <c>CCC</c>
// 	</a>

// Get a reference to the 1st child.
CkoXml *xB = [xml GetChild: [NSNumber numberWithInt: 0]];

// Re-load "xml" with an entirely new document:
success = [xml LoadXml: @"<z><x>XXX</x></z>"];

// What happens to xB?
// The answer is nothing.  xB still points ot the "b" node in the original document, and the entire
// original document remains in memory.  We now have two XML documents in memory.

NSLog(@"%@",[xB GetXml]);

// output is:

//     <b>BBB</b>

// Make xB reference the root node of its document:
[xB GetRoot2];
NSLog(@"%@",[xB GetXml]);

// You can see here that the entire original XML document is still available
// because at least one node in the XML is referenced by a variable.
// The output is:

//     <?xml version="1.0" encoding="utf-8"?>
//     <a>
//         <b>BBB</b>
//         <c>CCC</c>
//     </a>

// We can also see that "xml" contains an entirely new XML document:
NSLog(@"%@",[xml GetXml]);

//     <?xml version="1.0" encoding="utf-8"?>
//     <z>
//         <x>XXX</x>
//     </z>
//