[OpenLayers-Users] Permalink doesn't update on addlayer/removelayer

[Andreas Hocevar]

On Aug 24, 2010, at 15:47 , Andreas Hocevar wrote:

> Ok, I do see yours and Marc's point now. You are not talking about using the Permalink control as-is, but with a custom createParams method and a custom ArgParser. In this case it can indeed be useful to listen to addlayer/removelayer.
> 
> So yes, the Peramlink control could be improved with a patch containing the snipped posted by Marc.

But then, a more proper fix would probably be to register the Permalink control's map event listeners in activate() rather than draw(). Now if users configure a custom createParams method, they can also register a listener to the control's activate event and add additional map listeners there.

Marc: and yes, this is what we would usually discuss in dev rather than users :-).

Regards,
Andreas.

> On Aug 24, 2010, at 15:30 , Slawomir Messner wrote:
> 
>> Hi all,
>> I thought permalink should have the information about visibility(and 
>> other stuff) and should refresh when this values change, then for me 
>> it's a bug when the initial values are not stored in the link (it's like 
>> the first change).
>> The other thing is the need for extra information about layers to load 
>> them at the beginning. Thanks for the link Andreas, I will visit it 
>> tomorrow. I didn't look for an external solution because Permalink and 
>> ArgParams are easy to extend and the informations are not complex. But 
>> who knows, maybe there will be more data to store, so I will visit your 
>> link, thx.
>> Regards,
>> Slawomir
>> 
>> Am 24.08.2010 15:15, schrieb Marc Jansen:
>>> Hi Andreas,
>>> 
>>> first of all, sorry for cross-posting in the past. I thought it was
>>> useful in this case.
>>> 
>>> I'd disagree about the not handling of the layeradd/layerremove event
>>> for the Permalink-control -- but can easily live without this addition
>>> to OpenLayers :-)
>>> 
>>> Your suggestions of alternative ways of handling application "state" are
>>> valid and often better suited, yet I think the addition of two
>>> additional listeners to the control would be very intuitive.
>>> 
>>> Best regards,
>>> 
>>> Marc
>>> 
>>> 
>>> 
>>> On 24.08.2010 14:49, Andreas Hocevar wrote:
>>>> Hi,
>>>> 
>>>> first of all, please don't cross-post dev and users.
>>>> 
>>>> I am not sure if a permalink as provided by OpenLayers is what you really want for applications where the user can add or remove layers. The permalink only stores the visible/invisible state of the available layers in their order. It does not know anything about what these layers are. So a permalink will look exactly the same for any map with the same extent with let's say 3 layers that are all visible.
>>>> 
>>>> If you want to store information on what layers are actually configured, you should look into Format.WMC, Format.OWS or solutions like the OpenGeo Suite's GeoExplorer (http://suite.opengeo.org/geoexplorer), which stores layer configurations in a database and provides a permalink with a map id.
>>>> 
>>>> Regards,
>>>> Andreas.
>>>> 
>>>> On Aug 24, 2010, at 14:31 , Marc Jansen wrote:
>>>> 
>>>> 
>>>>> Hi Slawomir,
>>>>> 
>>>>> I'd consider this a bug with a (on first sight) reasonable easy fix:
>>>>> 
>>>>> In the Permalinks draw-method:
>>>>> 
>>>>>         this.map.events.on({
>>>>>             'moveend': this.updateLink,
>>>>>             'changelayer': this.updateLink,
>>>>>             'changebaselayer': this.updateLink,
>>>>>             'addlayer': this.updateLink,
>>>>>             'removelayer': this.updateLink,
>>>>>             scope: this
>>>>>         });
>>>>> 
>>>>> Or one could think of triggering a changelayer event when a layer has
>>>>> been added/removed in Map.js.
>>>>> 
>>>>> I am unsure which design is better, so I'd suggest opening up a ticket
>>>>> (I cc'ed the developer list so the core developers notice this discussion).
>>>>> 
>>>>> Regards,
>>>>> Marc
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> On 24.08.2010 13:53, Slawomir Messner wrote:
>>>>> 
>>>>>>   Hello,
>>>>>> Does anyone know why Permalink doesn't listen to addlayer/removelayer?
>>>>>> Every time I add a new layer I have to change a property(i.e.
>>>>>> visibility) to refresh the link. It's a bug or a feature?
>>>>>> Regards,
>>>>>> Slawomir
>>>>>> 
>>>>>> 
>>>>> _______________________________________________
>>>>> Dev mailing list
>>>>> Dev at openlayers.org
>>>>> http://openlayers.org/mailman/listinfo/dev
>>>>> 
>>>> 
>>> 
>> 
>> 
>> -- 
>> -----------------------------------------------
>> Slawomir Messner
>> Forschungszentrum "Deutscher Sprachatlas"
>> 06421-28-24981
>> 
>> _______________________________________________
>> Users mailing list
>> Users at openlayers.org
>> http://openlayers.org/mailman/listinfo/users
> 
> -- 
> Andreas Hocevar
> OpenGeo - http://opengeo.org/
> Expert service straight from the developers.
> 
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-- 
Andreas Hocevar
OpenGeo - http://opengeo.org/
Expert service straight from the developers.