[OpenLayers-Users] Re: remove a layer by name

[Puneet Kishor]

On Sep 26, 2011, at 12:57 PM, Armin Burger wrote:

> 
> 
> On 26/09/2011 05:31, Puneet Kishor wrote:
> 
>> 
>> The following code does what I want --
>> 
>> 	var lyr_list = map.getLayersByName("a_layer");
>>         if (typeOf(lyr_list) === "array") {
>>         	for (var i in lyr_list) {
>>                 	lyr_list[i].removeAllFeatures();
>>                         removeLayer(lyr_list[i]);
>>                 }
>> 	}
>> 
> > Surely, the above couldn't be the most optimum way, could it?
> 
> 
> it will not change anything for your particular case, but I usually reference layers via their ID. This requires to add the ID after creation.
> 
> something like
> 
> var myLayer = new OpenLayers.Layer...;
> myLayer.addOptions({id:'theLayerId'});
> 
> then you can always access the layer later on like
> 
> var mapLayer = map.getLayer('theLayerId');


Thanks Armin, but you are correct, it doesn't change anything for me. I have no problems "getting" the layer. I just am unable to use that layer to remove it effectively (and, I'd prefer to continue getting the layer via its name).

Some of the things I don't understand --

Why is a layer list returned and not just a layer when I `getLayersByName`? In other words, under what use case would there be more than one layers with the same name?

Why is a layer removed from the layer switcher via `removeLayer(layerObj)` but its features not removed? What could be the use of that functionality?

Why are the features of a layer removed from the map via `removeAllFeatures()` but the layer not removed? (although I can see the point of that).

Having a clear distinction between removing the features, removing the layer, and destroying the layer would also be very useful.


> 
> 
> For completely deleting a layer it might be necessary to also run the .destroy() method on the layer, but I'm not sure when this is required and when not.
> 
> Regards
> Armin
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