Re: [Pyobjc-dev] Article on MacDevCenter

[Bill B. <bb...@co...>]

On Saturday, Feb 1, 2003, at 13:37 US/Eastern, Dinu Gherman wrote:
>> http://www.macdevcenter.com/pub/a/mac/2003/01/31/pyobjc_one.html
>
> Nice and a good move! All I have to "criticize" is that there is not
> quite enough of an emphasis on mutable vs. unmutable objects, both
> in Python and the Foundation framework (Tuples/Lists vs. NSArray/
> NSMutableArray, say) and the PyObjC bridging between them. Or is
> that no issue at all?

Definitely an issue -- but the bridge "handles" it in the same fashion  
that ObjC "handles" it:

 >>> a = NSArray.arrayWithArray_([1,2,3,4,5])
 >>> a
<NSCFArray objective-c instance 0x50290>
 >>> a[0] = 5
Traceback (most recent call last):
   File "<stdin>", line 1, in ?
   File  
"/Library/Frameworks/Python.framework/Versions/2.3/lib/python2.3/site- 
packages/objc/_convenience.py", line 173, in <lambda>
     ('__setitem__', lambda self, index, anObject:  
self.replaceObjectAtIndex_withObject_(index, anObject)),
objc.error: NSInternalInconsistencyException - *** -[NSCFArray  
replaceObjectAtIndex:withObject:]: mutating method sent to immutable  
object

If you need a mutable array, you can create one in a couple of  
different ways:

 >>> a = a.mutableCopy()
 >>> a[0] = 5
 >>> from Foundation import Conversion
 >>> x = Conversion.pythonCollectionFromPropertyList(a)

Well, that last one *will* work after I fix a bug in the Conversion  
module. :-)

> I'm curious for the next parts! Any hints on when to expect them?

After 0.9...

The next article will discuss the construction of a trimmed down  
version of Web Services Tool -- WST without the dynamic toolbar,  
basically.

A good example as it nicely demonstrates how to build a multi-window  
style app [actually -- I *could* do it as a multi-doc app example] that  
leverages the incredible ease with which Python can communicate to  
XML-RPC servers.

b.bum