[OpenLayers-Users] Creating styles based on the values of calculated variables.

[Mak Kolybabi]

On 07/14/2010 09:40 AM, Dheeraj Chand wrote:
> I am curious if anyone has done something like what I am trying to do.  My goal is to allow a user to select any two variables by means of a form.  These variables could be, say, the number of people in Texas, by county, from 1991 to 1999.   The goal is then to create a new variable, Var3, where Var3 = (Var1 - Var2) and then style  the entire map based on the value of Var3.  (Each variable would obviously represent an attribute of the layer) I have got everything down except how to build a style based on the value of a derived variable.  Any advice?

Not sure if this is exactly what you're looking for, but it's possible to have a
style that has function-backed portions:

>       style_park = new OpenLayers.Style(
>           {
>               display: "${display}",
>               externalGraphic: "/images/park/sk-park.png",
>               // Original is 97x97.
>               graphicWidth: 25,
>               graphicHeight: 25
>           },
>           {
>               context: {
>                   display: function (feature) {
>                       return (feature.data.url) ? "show" : "none";
>                   }
>               }
>           }
>       );



-- 
Mak Kolybabi
Programmer
Telenium Inc.
204-957-2821