[OpenLayers-Dev] [strk@keybit.net: [OpenLayers-Users] Style context as an object ?]

[strk]

Guys, I'm forwarding this as I think what I'm trying to do
is limited by actual OL code.

Basically I'm trying to use an "instance object" as the
'context' for a Style.

The idea is to have generic style handlers exposed in the
drupal OpenLayers module. The genericity would be obtained
by defining classes which take parameters in the constructor
and expose methods basing their working on the passed parameters.

Example code is in the forwarded message.
The actual code I'm using is tested to work in a normal
(out of OpenLayers) context, that is I can instanciate
the class and access the parameters passed by the constructor
trough 'this' from the methods.

Problem is, when attaching the instance in the 'context'
property of a Style, later call to the methods don't
resolve 'this' to the object itself, but to the top
of DOM.

Can this be due to the Style.clone method ?
That method (lib/OpenLayers/Style.js) does:

        // clone context
        options.context = this.context && OpenLayers.Util.extend({}, this.context);

Would the OpenLayers.Util.extent call change the nature
of the context object ?
If so, is there anything required on the context class itself
to retain the nature ? (the reference to 'this') ?
Or, do you have other suggestions for workarounds ?

Thanks in advance.

--strk;

----- Forwarded message from strk <strk at keybit.net> -----

Date: Mon, 5 Jul 2010 17:41:51 +0200
From: strk <strk at keybit.net>
Subject: [OpenLayers-Users] Style context as an object ?
To: users at openlayers.org
X-BeenThere: users at openlayers.org
List-Id: OpenLayers User discussion <users.openlayers.org>

Did anyone ever tried using a "proper" object
as a Style context ?

What I'm trying to do is create a class of style
contexts and pass instances of them (for parametrized
styles) as a Style.context, but 'this', within the
callbacks, seem to always evaluate to the top of DOM.

Example code:

  MyContextClass = function(radius) {
  	this.radius = radius;
  };
  
  MyContextClass.prototype.getRadius() {
  	alert(this.radius);
  };
  
  myContext = new MyContextClass(4);
  
  myStyle = OpenLayers.Style(
  	{ pointRadius: '${getRadius)' },
  	{ context: myContext }
  );

--strk; 

  ()   Free GIS & Flash consultant/developer
  /\   http://strk.keybit.net/services.html
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----- End forwarded message -----