macOS Sorting NSArray of NSXMLNodes

[wildwobby]

Hi,

I am making an app that fetches XML data from the internet and put it into a NSTableView. It is like Chapter 28 in the new 'Cocoa Programming for Mac OS X ed. 3' except it used the Digg API instead. The problem is, the NSTableView can't sort the rows. Does anyone have any ideas of how I can make it sortable? What should the Sort Key be for each column be in IB?

Any help appreciated!

 

[lee1210]

This page discusses this:
http://www.cocoadev.com/index.pl?NSTableViewSort

I guess you're not sorting your own class, but if you were you'd implement:

- (NSComparisonResult)compare:(MyClassName *)

You might need to extend NSXMLNode and only implement a compare method. I don't know what you'd compare by (stringValue?), but you could do it however you wanted in that method.

It looks like you'll need to use a NSMutableArray instead of NSArray, so you can perform the sort, or you can run: sortedArrayUsingSelector on the plan NSArray, but you're getting a new NSArray *, it's not sorted in place.

-Lee

 

[wildwobby]

I tried making a category for NSXMLNode with this method:

- (NSComparisonResult)compareDiggCount:(NSXMLNode *)n
{	
	NSError *error;
	NSString *xp = @"@digg";
	NSArray *nodes = [n nodesForXPath:xp error:&error];
	if (!nodes){
		NSAlert *alert = [NSAlert alertWithError:error];
		[alert runModal];
		return NSOrderedSame;
	}
	if([nodes count] == 0)
	{
		return NSOrderedSame;
	}else{
		NSLog(@"int val!:%@", [[nodes objectAtIndex:0] stringValue]);
	}
	return NSOrderedSame;
}

However, it is not getting called anyways... In IB for the digg column I put:'compareDiggCount:' for the selector... although I'm still unsure of what to put for sort key..

 

[Catfish_Man]

Check out http://developer.apple.com/document...SortDescriptor_Class/Reference/Reference.html

 

[Nutter]

(...never mind...)

 

[wildwobby]

Im not as focussed on how bad the method is.... I want to fix it so it actually gets called first. What could I be doing wrong?

 

[ATG]

Im not as focussed on how bad the method is.... I want to fix it so it actually gets called first. What could I be doing wrong?

Change:

- (NSComparisonResult)compareDiggCount:(NSXMLNode *)n

to:

- (NSComparisonResult)compare:(NSXMLNode *)n

Although the previous poster is right, you should be really be using NSSortDescriptor. Also, putting an NSAlert in a compare method is a very bad idea. compare methods get called a lot.