[OpenLayers-Dev] Re: TransformFeature control destroy function seems to have a bug

[Andreas Hocevar]

Hi,

the rule is simple - a common paradigm (not only in software engineering) says: the one who creates something is responsible for cleaning it up. This means that you should not destroy features (i.e. the trasformation box) that others (the TransformFeature control) create.

If you think that this is something that should be explained, please provide a documentation patch.

Regards,
Andreas.

On Sep 21, 2010, at 11:22 , Fabian Patzke (OL) wrote:

> 
> Hi,
> 
> Andreas Hocevar-2 wrote:
>> 
>> what you are describing here can only happen if you "delete everything in
>> the used vector layer" *before* you "deactivate the control".
>> 
> That's true, that was my approach. I deleted everything first.
> 
> Andreas Hocevar-2 wrote:
>> 
>> If you have double-checked that you deactivate the control before removing
>> the features from the layer and still see the issue, then please create a
>> ticket with a test case or a minimal example that shows the problem.
>> 
>> Regards,
>> Andreas.
>> 
> So this is my fault using a wrong sequence of actions. Maybe it should be
> made a bit more clear somewhere that one has to follow a certain kind of
> order to clear any digitize procedure? Because for me it was not obvious
> that it is a fault to first empty and then deactivate and destroy controls.
> 
> Greetings,
> Fabian
> 
> Andreas Hocevar-2 wrote:
>> 
>> On Sep 20, 2010, at 16:07 , Fabian Patzke (OL) wrote:
>> 
>>> 
>>> Hi, it seems that the TransformFeature control has a broken destroy
>>> function
>>> or maybe its just me doing something forbidden. When you try to destroy
>>> the
>>> control there can be an error in line 565. For me it happens when I do
>>> the
>>> following.
>>> - start the map
>>> - start using the TransformFeature control
>>> - deactivate the control and delete everything in the used vector layer
>>> (I
>>> do this because I want a clear map after I used any kind of digi control)
>>> - using TransformFeature.destroy() now throws an error, because there is
>>> no
>>> geometry in the box left.
>>> 
>>> shouldn't there be a kind of check if the box has no geometry?
>>> 
>>> If someone else thinks that is a bug and not me using it the wrong way, I
>>> would create a ticket.
>>> Greetings,
>>> Fabian
>>> 
>>> I made this patch and it works for me:
>>> 
>>> Index: lib/OpenLayers/Control/TransformFeature.js
>>> ===================================================================
>>> --- lib/OpenLayers/Control/TransformFeature.js	(revision 10773)
>>> +++ lib/OpenLayers/Control/TransformFeature.js	(working copy)
>>> @@ -561,12 +561,14 @@
>>>     */
>>>    destroy: function() {
>>>        var geom;
>>> -        for(var i=0; i<8; ++i) {
>>> -            geom = this.box.geometry.components[i];
>>> -            geom._handle.destroy();
>>> -            geom._handle = null;
>>> -            geom._rotationHandle && geom._rotationHandle.destroy();
>>> -            geom._rotationHandle = null;
>>> +        if (this.box.geometry != null) {
>>> +            for(var i=0; i<8; ++i) {
>>> +                geom = this.box.geometry.components[i];
>>> +                geom._handle.destroy();
>>> +                geom._handle = null;
>>> +                geom._rotationHandle && geom._rotationHandle.destroy();
>>> +                geom._rotationHandle = null;
>>> +            }
>>>        }
>>>        this.box.destroy();
>>>        this.box = null;
>>> -- 
>>> View this message in context:
>>> http://osgeo-org.1803224.n2.nabble.com/TransformFeature-control-destroy-function-seems-to-have-a-bug-tp5550628p5550628.html
>>> Sent from the OpenLayers Dev mailing list archive at Nabble.com.
>>> _______________________________________________
>>> Dev mailing list
>>> Dev at lists.osgeo.org
>>> http://lists.osgeo.org/mailman/listinfo/openlayers-dev
>> 
>> 
>> 
>> -- 
>> Andreas Hocevar
>> OpenGeo - http://opengeo.org/
>> Expert service straight from the developers.
>> 
>> _______________________________________________
>> Dev mailing list
>> Dev at lists.osgeo.org
>> http://lists.osgeo.org/mailman/listinfo/openlayers-dev
>> 
>> 
> 
> -- 
> View this message in context: http://osgeo-org.1803224.n2.nabble.com/TransformFeature-control-destroy-function-seems-to-have-a-bug-tp5550628p5553874.html
> Sent from the OpenLayers Dev mailing list archive at Nabble.com.
> _______________________________________________
> Dev mailing list
> Dev at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/openlayers-dev



-- 
Andreas Hocevar
OpenGeo - http://opengeo.org/
Expert service straight from the developers.