[OpenLayers-Dev] Bug in rendering features with cluster strategy

[Tim Schaub]

Hey-

Eric Lemoine wrote:
> Yes. Especially since drawFeature is often called from addFeatures,
> where we're assured that the feature is in the layer. So, instead, we
> may want to change the select feature control so that it calls
> drawFeature only if, in the case of selection, the feature is in the
> "features" array, and in the case of unselection, the feature is in
> the "selectedFeatures" array. What do you think? Eric
> 

The problem is in the Feature handler.  We destroy features, but 
references to them are still truthy.  Since the destroy code sets the 
layer property to null, one check of an undestroyed feature is to check 
feature.layer.

See http://trac.openlayers.org/attachment/ticket/1806/destroyed.patch

> 2008/11/4, Tim Schaub <tschaub at opengeo.org>:
>> Hey-
>>
>> Ivan Grcic wrote:
>>> OK... i found it..inside Layer.Vector...now the question is: should i
>>> put something like this:
>>>
>>> if (OpenLayers.Util.indexOf(this.features, feature) != -1){
>>>
>>> inside drawFeature: function(feature, style) {
>> Nope.  Making drawFeature that safe at the expense of iterating through
>> every feature with every draw is a mistake.
>>
>>> or inside every other function inside Layer.Vector that uses
>>> drawFeature function?
>>>
>>> When I put it here:
>>>
>>>     drawFeature: function(feature, style) {
>>> -->	if (OpenLayers.Util.indexOf(this.features, feature) != -1){
>>> ..
>>> ..
>>>      }
>>> }
>>>
>>> it works pretty fine for me :) Eric?
>>>
>>> On Mon, Nov 3, 2008 at 9:53 AM, Ivan Grcic <ivan.grcic at geofoto.hr> wrote:
>>>> Yup, its not Cluster Strategy...
>>>> http://trac.openlayers.org/ticket/1806#comment:2
>>>>
>>>> On Mon, Nov 3, 2008 at 9:11 AM, Eric Lemoine <eric.c2c at gmail.com> wrote:
>>>>> Hi.
>>>>>
>>>>> Yes, this looks like a bug in OpenLayers.
>>>>>
>>>>> I'm under the impression that this isn't a bug in the cluster strategy
>>>>> but either in Layer.Vector or in Control.SelectFeature. Indeed, I
>>>>> think SelectFeature calls layer.drawFeature on feature
>>>>> selection/unselection without checking whether the feature is in the
>>>>> layer. And i'm saying this may be a bug in Layer.Vector because it may
>>>>> be that drawFeature should be responsible for checking whether the
>>>>> feature is in the layer before actually drawing it.
>>>>>
>>>>> This is just coming from the top of my head so i may be wrong, but i'm
>>>>> feeling this is a good track to follow :)
>>>>>
>>>>> Eric
>>>>>
>>>>> 2008/11/2, Ivan Grcic <ivan.grcic at geofoto.hr>:
>>>>>> Hi list,
>>>>>>
>>>>>> i discovered a bug while developing my OL application, in cluster
>>>>>> strategy class.
>>>>>>
>>>>>> Bug occurs when you hover over one feature that represent a cluster
>>>>>> (or externalGraphic or like in cluster example - vector circle
>>>>>> http://openlayers.org/dev/examples/strategy-cluster.html)
>>>>>>
>>>>>> When you zoom in/out while that feature-cluster is selected (by
>>>>>> quickly double-clicking or easier using scroll on ur mouse), on next
>>>>>> zoom that cluster is rendered (stays on screen) together with newly
>>>>>> created clusters! And clearly it shouldnt be there. The old
>>>>>> ("phantom") cluster is not selectable, as he doesnt exist on the new
>>>>>> zoom level..he just stays there on screen...annoying me :)
>>>>>>
>>>>>> As you zoom in again and again, phantom clusters always render, always
>>>>>> at the same position in the map div...
>>>>>>
>>>>>> Please confirm that this is a bug, im going crazy here with this one :|
>>>>>>
>>>>>> --
>>>>>> Ivan Grcic
>>>>>> _______________________________________________
>>>>>> Dev mailing list
>>>>>> Dev at openlayers.org
>>>>>> http://openlayers.org/mailman/listinfo/dev
>>>>>>
>>>>
>>>> --
>>>> Ivan Grcic
>>>>
>>>
>>>
>>
>> --
>> Tim Schaub
>> OpenGeo - http://opengeo.org
>> Expert service straight from the developers.
>> _______________________________________________
>> Dev mailing list
>> Dev at openlayers.org
>> http://openlayers.org/mailman/listinfo/dev
>>


-- 
Tim Schaub
OpenGeo - http://opengeo.org
Expert service straight from the developers.