[OpenLayers-Dev] Cluster strategy should not process data when layer is currently disabled (visibility=false)

Alexandre Dube adube at mapgears.com
Thu Nov 13 09:02:11 EST 2008

I get the same behavior as Ivan's on my application which has very 
similar resolution settings on map an vector layer.

Because a layer's features are not destroyed when it goes out of range 
(inRange) or becomes invisible (visibility), the cluster strategy still 
clusters those existing features. I don't have that many features to 
display when the layer becomes inRange, so I never noticed any slowing down.


Ivan Grcic wrote:
> This post evolved from previous discussion named "bbox strategy and zooming"
> Clustering features with cluster strategy takes some time. If there
> are many features to cluster, it will take even more time :)
> So there are some scenarios where clustering shouldnt be recalculated.
> Example:
> I want to see my cluster layer only after 5th zoom level. No
> clustering should be made when i play on zoom level 0-4 with other
> layers,
>  because it slows things down, and the cluster layer is still not
> visible at all (its only clustering features in background)
> It should only cluster when layer is visible (and the current map
> resolution is inside array resolution of clustered layer, if we define
> seperate set of resolution)
> So if map has:
> resolutions: [0,1,2,3,4,5,6,7,8,9]
> and vector layer:
> resolutions: [5, 6, 7, 8, 9]
> clustering should occur only on vector layers resolution :5, 6, 7, 8 and 9.
> I hope you see where im pointing now,
> Best regards,

Alexandre Dubé

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