[OpenLayers-Dev] DeleteFeature control

[Eric Lemoine]

On Monday, July 20, 2009, Alexandre Dube <adube at mapgears.com> wrote:
> Hi Eric,
>
> Eric Lemoine wrote:
>
>   (I never used Protocol.MapFish and Strategy.Save together, I'm curious
> to know why they don't play together)
>
>
>
>
> I haven't tried either, but in the past I tried the HTTP protocol + featureserver and the Save strategy wasn't able to read the insertedId of the response received.  I should simply try it and see what's the status now...

right. But a patch was committed before 2.8, so there's chance that
the save strategy and the mapfish protocol actually work together.


>
>
>
>
> So long that the control user can be notified when a feature is
> deleted I don't see the value of having the control committing the
> changes.
>
>
>
>
>
> Ok
>
>
> I don't understand. Can't you listen to "featuredeleted" from your
> control and trigger saveStrategy.save()? (assuming Strategy.Save work
> with Protocol.MapFish).
>
>
>
>
> Yes.  I just wondered if it was better to do it internally...
>
>
> Some general comments on your control: from my understanding the
> control has two activities, (1) when a feature is selected change its
> state and redraw it, (2) when some delete key is pressed trigger
> events. Since they are *independent* activities they could be done by
> independent controls, and I think I'd disagree with wiring independent
> activities within a single control.
>
> If we had support for composite controls in the base Control class one
> could do something like what follows to implement your delete
> control's behavior:
>
> var delCtrl = new OpenLayers.Control({
>     handler: new OpenLayers.Handler.Keyboard({
>         keydown: function(evt) {
>              var delKey = ...
>              if(delKey) {
>                  saveStrategy.save();
>              }
>         }
>     }),
>     controls: [
>         new OpenLayers.Control.SelectFeature(
>             layer, {
>                 onSelect: function(f) {
>                     f.state = DELETE;
>                     this.layer.drawFeature(f);
>                 }
>         })
>     ]
> });
>
>
>
> If I understand correctly, you would disagree to have this control added as a new OpenLayers official control because of its 2 independent actions, so you suggest instead I should define a customized control like above but it requires to have controls within the control to be automatically activated/deactivated on 'this' control activation/deactivation.  Is that it ?

That's basically it, yes. But I may wrong, and there may be value in
combining these two independent activities (as a helper control), I'm
just not convinced at this point. To get to the delete control


>
>
> (the support for composing controls I mentioned above involves having
> the base Control class activates and deactivates every control that's
> passed in the "controls" option.)
>
> What do you think?
>
> Cheers,
>
>
>
>
> About the 'controls' property and the act./dea. automatism : that's a good idea, but wouldn't it be good to have a 'handlers' property also and activate/deactivate all handlers as well ?  Currently, control has a 'handler' property only.  Would it make sense to have 'handlers' added a do the same kind of automatism as the new 'controls' property ?
>
> Regards,
>
> Alexandre
>
>
>
>
>
>
>   Any hint would be appreciated,
>
> Alexandre
>
> Alexandre Dube wrote:
>
>
> Hi,
>
>   I just sent (finally) a new patch for ticket 1882 (1) (DeleteFeature
> control) and set the status to review.
>
> (1) http://trac.openlayers.org/ticket/1882
>
> Regards,
>
>
>
>
> --
> Alexandre Dubé
> Mapgears
> www.mapgears.com
>
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>
>
>
>
>
>
>
>
>
> --
> Alexandre Dubé
> Mapgears
> www.mapgears.com
>
>

-- 
Eric Lemoine

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