Single model update for multiple changes in NSArrayController subclass

Question

I implemented an NSArrayController subclass to implement row reordering with bindings, using the code included in this post as a starting point. In the -tableView:acceptDrop:row:dropOperation: method, I perform the following:

[self removeObjectAtArrangedObjectIndex:removeIndex];
[self insertObject:object atArrangedObjectIndex:insertIndex];

The above code updates the model twice (one for each statement). For my purposes, I would like to have only one update.

Is there any way to achieve this?

Thanks.

Why do you need the single update in the first place? That information might help us to get a better suited answer.. — cacau, May 13 '14 at 06:01
As I mention in my question, I am implementing row reordering. I only consider that it is semantically appropriate to have a single update if a row gets rearranged (deleted+inserted) — insys, May 14 '14 at 05:57

score 0 · Answer 1 · answered May 13 '14 at 06:34

0

There's always the possibility of replacing the entire array if you want to incorporate many changes to an array into a single operation.

This might have unexpected effects for e.g. objects in the UI bound to your array, though.

answered May 13 '14 at 06:34

cacau

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Thanks for your answer. May I ask if you could point to the relevant method? – insys May 14 '14 at 06:01

score 0 · Accepted Answer · answered Jul 03 '14 at 07:16

I ended up doing the following:

[_content removeObject: [objects objectAtIndex: removeIndex]]; // < Here's the hack
[self insertObject:object atArrangedObjectIndex:insertIndex];

Where _content is in fact the content array of the controller.
The above works fine in my case (as described in my question).

Single model update for multiple changes in NSArrayController subclass

2 Answers2