Buffer around all geometries

[DanielWebb2]

I’m looking to create one buffer around multiple graphics.

The user clicks the desired polygons, which creates graphics matching the geometry of the polygons. After certain ones are picked I want to buffer around all of those with the same shape they all have together.  Below is the code I’m trying for the buffer.

It always break on gsvc.buffer(params, showBuffer); which makes me think there’s a problem with the params.

var geom = new Graphic();

geom = graphicsLayer.graphics;

var selectedGeom = graphicsUtils.getGeometries(geom);

var bufferDist = Math.floor(dom.byId("txtBufferDist").value);

var params = new BufferParameters();

params.geometries = [selectedGeom];

params.distances = [bufferDist];

params.unit = GeometryService.UNIT_FOOT;

params.outSpatialReference = bcMap.spatialReference;

gsvc.buffer(params, showBuffer);

function showBuffer(){

     //Code

}

HOWEVER, if I use graphicsUtils.graphicsExtent instead of graphicsUtils.getGeometries it works. But I don’t want a square every time. I want the buffer to follow the outline shape as seen in yellow.

Thanks for any help.

[RobertScheitlin__GISP · Accepted solution]

Daniel,

  So it looks like your issue is that graphicUtil.getGeometries returns an array and you then are putting that array inside another array here:

params.geometries = [selectedGeom];

Try:

params.geometries = selectedGeom;

You also are start the geom var as a Graphics and then overwrite it with an array of Graphics:

var geom = new Graphic();
geom = graphicsLayer.graphics;

This is no big deal as you are overwriting it but there is no need to start it as a Graphic and then set it to an Array. This would make more sense:

var graphics = graphicsLayer.graphics;
var selectedGeoms = graphicsUtils.getGeometries(graphics);

[DanielWebb2]

Thanks a ton! That basically got it.  Now it makes a graphic around each polygon.  This at least gets past my wall gives me something else to look into.  I’m hoping to get one single graphic as a buffer.

Thanks again.

[RobertScheitlin__GISP]

Daniel,

  for that you just need to set the unionResults to true for the BufferParameters

[DanielWebb2]

You rock!  It was so simple!  Now I feel dumb for missing that property.  I was trying to figure how to make esri/dijit/editing/Union or esri/dijit/analysis/MergeLayers work.

Thanks for your help.