[OpenLayers-Users] Text labels

[Paul Spencer]

A simpler styleMap would be to take the Name directly from the  
feature's attributes, but using a context to provide functions that  
calculate per-feature styles is very powerful

var styleMap = new OpenLayers.StyleMap({
   default: OpenLayers.Util.applyDefaults({
     label: '${Name}', // this comes from feature.attributes.Name and  
is case sensitive
     strokeWidth:1,
     strokeColor:"#CCCCCC",
     fillColor: "green"
   })
});

Cheers

Paul

On 2009-09-29, at 5:28 AM, Jan H. van der Ven wrote:

> Dear Nicholas,
>
>
> I use a StyleMap like so:
>
>    var styleMap = new OpenLayers.StyleMap(
>    {
>      "default":OpenLayers.Util.applyDefaults(
>      {
>        fillColor: stateColors[layerIndex],
>        fillOpacity: 0.4,
>        strokeColor: stateColors[layerIndex],
>        strokeWidth: 2,
>        label : "${getName}", // see context below
>        labelAlign: "cm",
>        fontColor: "yellow",
>        fontSize: "12px",
>        fontFamily: "Verdana",
>        fontWeight: "bold"
>      }
>      ,OpenLayers.Feature.Vector.style["default"])
>
> ,"select":OpenLayers.Util.applyDefaults 
> ({},OpenLayers.Feature.Vector.style["select"])
>    });
>    // the labelFunction prevents the modify handles being labeled with
> "undefined"
>    styleMap.styles["default"].context={getName: labelFunction};
>
> This StyleMap is then added as a parameter to the layer:
>    var laag = new OpenLayers.Layer.GML(
>    layerName,
>    url,
>    {
>      format:OpenLayers.Format.GeoJSON,
>      visibility:false,
>      styleMap:styleMap,
>      isBaseLayer:false,
>    });
>
> And the labelFunction is used to show the label only at a certain zoom
> level:
>
>  function labelFunction(feature){
>      if (map.getZoom()>4){
>        if (feature.attributes.name != undefined){
>          return feature.attributes.name;
>        }else{
>          return '';
>        }
>      }else{
>        return '';
>      }
>    }
>
> The part about undefined has to do with edit handles.
>
> Kind regards,
>
>
> Jan
>
> Nicholas Efremov-Kendall wrote:
>> Hi all,
>>
>> Sorry to bug you all with a pretty simple question. I have a shp file
>> converted to GML, with an attribute called "name." I'd like for this
>> to be places as a label by the polygon feature. I think, based on my
>> digging around on the lists that I need a function to first get the
>> feature.attributes.Name <http://feature.attributes.Name>, which would
>> then pass it to the label. Does anyone have a good example of this,  
>> or
>> suggestions on implementation?
>>
>> var cities = new OpenLayers.Layer.GML ("7th Century Cities",
>> "data/cities.gml",
>> {
>> style: {strokeWidth:1, strokeColor:"#CCCCCC", fillColor: "green"},
>> projection: new OpenLayers.Projection("EPSG:4326"),
>> format: OpenLayers.Format.GML,
>>
>>              label: "$name",
>>
>>
>> }
>> );
>> map.addLayer(cities);
>>
>>
>> -- 
>> Nicholas Efremov-Kendall
>> Fulbright Student 2009-2010, Ukraine
>> nefremov at artsci.wustl.edu <mailto:nefremov at artsci.wustl.edu>
>> c/o Halyna Yerko
>> Balzaka 92a, Kv 27
>> 02232
>> Kyiv, Ukraine
>> (mob) +380963576524
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