[OpenLayers-Dev] using custom renderer on Layer.Vector

[Bart van den Eijnden]

Thanks Chris, this is exactly the kind of feedback I was looking for. I'll open up an enhancement ticket with your suggestion.

Best regards,
Bart

On Jun 10, 2010, at 12:59 PM, <christopher.schmidt at nokia.com> <christopher.schmidt at nokia.com> wrote:

> 
> On Jun 10, 2010, at 3:32 AM, ext Bart van den Eijnden wrote:
> 
>> Hi list,
>> 
>> I am trying to use a custom renderer for a Vector Layer. However, if I interpret the code correctly, there is an issue there right now. Hopefully somebody can clarify if I am doing something wrong.
> 
> Bart:
> 
> I would say that this is not the right way to go about it. Instead,
> the right thing to do is to pass in a renderers array like so:
> 
> Layer.Vector("", {
>  renderers: [Geozet.Renderer.Anchor]
> })
> 
> Setting 'renderers' in a Vector layer's option is documented (in the
> form of an example) and is the only way I had originally considered
> allowing users to control the renderer code; this was to ensure that 
> by default, OpenLayers would check things like the .supported()
> call, etc.
> 
> However, the current code requires renderers to be in OpenLayers.Renderer
> namespace, so clearly this won't work for you. 
> 
> While the suggestion you had is not unreasonable, my first suggestion 
> would be to change the .renderers array to support storing
> actual classnames. The reason that we don't do that in *general* is
> because we wanted to be able to allow users to exclude renderers,
> and not have their OL file break, which would not work with actual
> classnames. However, there's no reason we can't check if the passed 
> in thing is a string or an object, and do the right thing either way.
> 
> If you look in the assignRenderer function, you can see that the 
> renderer is instantiated with a div and rendererOptions.
> 
> In reality, there's no reason not to pursue both of these -- however,
> if I were mucking about with making things APIProperties, the .renderers
> array is the one that I would go for first.
> 
> -- Chris
> 
>> I am defining my layer in the following way:
>> 
>>   vectorLayer = new OpenLayers.Layer.Vector("Bekendmakingen", {
>>       styleMap: new OpenLayers.StyleMap({'default':{
>>           cssClass: "${category}"
>>       }}),
>>       renderer: new Geozet.Renderer.Anchor(),
>>       strategies: [new Geozet.Strategy.PrintList()]
>>   });
>> 
>> However, the constructor of the renderer normally gets the root div as the first argument, but since the vectorLayer has not yet been rendered, I cannot assign it as yet.
>> 
>> If I look in the Vector.js code I see in the initialize function:
>> 
>>       OpenLayers.Layer.prototype.initialize.apply(this, arguments);
>> 
>>       // allow user-set renderer, otherwise assign one
>>       if (!this.renderer || !this.renderer.supported()) {
>>           this.assignRenderer();
>>       }
>> 
>> So after the prototype initialize has been called, this.div is there, and I need to "assign' it to my custom renderer.
>> 
>> So I would expect:
>> 
>> Renderer to have a setContainer function, and the constructor of the Vector layer to use that function if a user-set renderer has been used.
>> 
>> TIA.
>> 
>> Best regards,
>> Bart
>> _______________________________________________
>> Dev mailing list
>> Dev at openlayers.org
>> http://openlayers.org/mailman/listinfo/dev
> 
> Regards,
> -- 
> Christopher Schmidt
> Nokia
> 
>