[Qgis-developer] problem with feature request and updateFeature

[Jürgen E. Fischer]

Hi Nathan,

On Sat, 23. Mar 2013 at 01:42:32 +1000, Nathan Woodrow wrote:
> What is the purpose of doing all the extra feature lookup in
> updateFeature?

To record just the changes on the undo stack and not load of changes that
actually don't change anything.

> To me this method is broken an shouldn't call getFeatures.

I don't see a way to currently get what changed without looking up the current
feature in the process.

> If we want to implement attribute change tracking it should be done on the
> QgsFeature, which would be easy, not in QgsVectorLayer.

features are not tied to layers.  QgsVectorLayer (and it's edit buffer)
currently track the changes to features of a layer.

The bug is that the providers have a notion of active iterators.  The iterators
should be independent, but currently aren't.   I think that's going to change
when threading is introduced - we are just not there yet.   If the iterators
were independent updateFeature would work fine.


Jürgen

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