[OpenLayers-Dev] API function and event for changing WMS LAYERS param?

Tim Schaub tschaub at opengeo.org
Tue Jul 14 12:44:27 EDT 2009


Hey-

Eric Lemoine wrote:
> On Tuesday, July 14, 2009,  <bartvde at osgis.nl> wrote:
>> Hi list,
>>
>> this came up on the geoext list [1], and Eric and I are interested how
>> other OL devs feel about this.
>>
>> Currently, when the LAYERS param is changed for an OpenLayers.Layer.WMS
>> layer, there is no way for an external component (like the GeoExt legend
>> panel), te know that something has changed and that they need to update
>> themselves.
>>
>> So what I was proposing is an API function updateLayersParam or something
>> similar, which will do the updating, and trigger a changelayer event with
>> property e.g. layersparam.
>>
>> Thoughts/comments more than welcome, also if people see other possible
>> solutions. Also on the naming ofcourse.
>>
>> If there is support for this, then I'll gladly create a ticket and a patch
>> with tests.
> 
> Hi Bart
> 
> updateLayersParam may be too specific. And actually we already have
> mergeNewParams for updating params so we could just make
> mergeNewParams trigger "changelayer" with "property" set to
> "mergenewparams" or something. With something like that, if one is
> interested in updates for the "layers" param only, one will have to
> manually check that the "layers" param has changed. That sounds
> reasonable to me.
> 

I agree.  No need for a new method, just notification (and I think 
"params" makes a fine value for the "property" property of the event).


Tim

> Cheers,
> 
>> Best regards.
>> Bart
>>
>> [1] http://www.geoext.org/pipermail/dev/2009-July/000249.html
>>
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>>
> 


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



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