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mdeh

macrumors 6502
Original poster
Jan 3, 2009
345
2
I wonder if I might ask for an insight into an issue in programming for IOS. ( This might equally apply to Mac OS, but not sure).

When using a UIDocument, the example I am following does the following...in very broad terms.

If Object_A changes, the document object is made aware of these changes once they are done. The "dirty" document has methods to save all the changes ( NSCoding) protocol etc. However, this seems to be insufficient, as property changes to Object_A might be missed, and a protocol to implement changes as each property on Object_A changes is implemented.

My question is this. Why is it not sufficient to have only the first of the two mechanisms. Any changes to the document ( it becomes dirty) causes Object_A to be written to disk, which includes any changes to it's properties.

Hopefully, this makes a little sense? :)
 
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