Re: Question on NSXMLNode and related classes

[Richard Frith-Macdonald]

On 28 Aug 2009, at 20:08, Doug Simons wrote:

> Hi Richard,
>
> Thanks for your reply! Actually, we're fairly heavily invested in  
> using the NSXMLNode API's. So if we were going to look at GSXML or  
> any other library, it would be as a means to implement those classes.

As you have decided to use the new Apple classes, your best bet seems  
to be to implement them on top of libxml2 ... which is what GSXML  
already does, so you should be able to re-use much of that code (I  
think it already does most of what the apple stuff does).

> I have no inside information about how Apple's implementation works,  
> but I see that libxml2 is installed on the system, so your  
> assumption that they use it seems reasonable. So probably building  
> the GNUstep implementation on that library will help to keep  
> everything compatible.

I spent some time with google, and managed to find some emails where  
people from Apple explicitly say their code is built on top of  
libxml2, so an implementation based on that for GNUstep is almost  
guaranteed to be able to fairly easily keep up with any further  
extensions Apple add.

> Here's a list of the methods we are using in these classes (it's  
> possible that I missed a couple, but this should be close):
>
> NSXMLNode Methods:

<snip>

I think that list is extensive enough that you practically need to  
implement the whole thing ... not difficult, but more time consuming  
than I can afford now (though I can always spare a bit of time to  
help).  It's possible you could write the NS classes as thin wrappers  
round the GSXML classes, but given the amount you want to do, I think  
you would be best advised to wrap libxml2 directly using the working  
code in the GSXML classes as an example of how libxml2 works and can  
be used, and copying chunks of code where it saves time.