[OpenLayers-Dev] Making BBOX strategy smarter - part2

[XinGang Li]

For large data, may be you can change the ratio depend on the map zoom
level.

On Thu, Nov 13, 2008 at 7:37 PM, Ivan Grcic <ivan.grcic at geofoto.hr> wrote:

> ...and now when i lowered the ratio on bbox strategy, i can see big
> difference in refreshing the data (discarding old ones, fetchin new
> ones)
> Before i didnt see it because it was always fetching data for much bigger
> area.
>
> So now I can say that bbox strategy works pretty well for me!
>
> On Thu, Nov 13, 2008 at 12:32 PM, Ivan Grcic <ivan.grcic at geofoto.hr>
> wrote:
> > Hi, i just saw that by default bbox has a ratio parameter:2 Creating
> > bbox strategy with lower value did a lot of improvement for me, since
> > it fetches much less data (filtering it)
> > The improvement is off course noticable more on larger scales (zoomed
> out)
> >
> > new OpenLayers.Strategy.BBOX({ratio:1.4}
> >
> > Regards, Ivan
> >
> > On Thu, Nov 13, 2008 at 12:04 AM, Christopher Schmidt
> > <crschmidt at metacarta.com> wrote:
> >> On Wed, Nov 12, 2008 at 11:20:00PM +0100, Ivan Grcic wrote:
> >>> This post continues on previous discussion opened under name "bbox
> >>> strategy and zooming"
> >>>
> >>> OK, I made a little mess here :) Im pretty new with this, so I still
> >>> dont know really well how things function.
> >>>
> >>> > Tim says
> >>> > Keep in mind that the cluster strategy doesn't know anything about
> bbox, and vice-versa.
> >>> So what  bbox does, is fetching the data, and cluster is then, well
> >>> clustering that data? (without getting any new data, cuz thats bbox'es
> >>> work)
> >>> So on layer pan/zoom, first bbox is activated to fetch, and then
> >>> cluster to process. Did i get it right?
> >>>
> >>> Well knowing that, then thers not so much to say about Cluster
> >>> strategy. Its allready doing its job pretty well.
> >>>
> >>> Its only about making bbox more efficient, cuz of reasons that
> >>> Tim/Christopher said:
> >>>
> >>> Tim said:
> >>> > I want to have maxfeatures, and more aggressive invalidation because
> of it.
> >>>
> >>> Christopher said (thats my case btw)
> >>> > Someone else might have a specific need to make the strategy more
> >>> > aggressive because the server returns more detailed data based on the
> >>> > extent of the request (I don't know, just making things up here).
> >>
> >> These are actually reversed -- I'm Tim above, and Tim is Me.
> >>
> >> Regards,
> >> --
> >> Christopher Schmidt
> >> MetaCarta
> >>
> >
> >
> >
> > --
> > Ivan Grcic
> >
>
>
>
> --
> Ivan Grcic
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>



-- 
Li XinGang
EMail: slinavlee at gmail.com
Blog:   avlee.cnblogs.com
Site:    www.mapboost.org.cn
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