topic Re: The issue is unionResults seems not working. in Web AppBuilder Custom Widgets Questions

The issue is unionResults seems not working.

ZhanGao — Wed, 03 Sep 2014 18:18:06 GMT

Try to develop buffer widget but the issue is unionResults seems not working

var params = new BufferParameters();

params.distances = [dom.byId("distance").value];

params.bufferSpatialReference = new esri.SpatialReference({ wkid: dom.byId("bufferSpatialReference").value });

params.outSpatialReference = this.map.spatialReference;

params.unit = GeometryService[dom.byId("unit").value];

params.unionResults = true;

The buffer cannot be dissolved.

Re: The issue is unionResults seems not working.

RobertScheitlin__GISP — Wed, 03 Sep 2014 18:58:39 GMT

Zhan,

What kind of error are you getting? Have you simplified your input geometries using GeometryService.simplify before attempting to buffer?

Re: The issue is unionResults seems not working.

ZhanGao — Thu, 04 Sep 2014 12:37:34 GMT

Hi, Robert

there is no error, but buffer cannot dissolve.

here is the code.

params.distances = [dom.byId("distance").value];
                  params.bufferSpatialReference = new esri.SpatialReference({ wkid: dom.byId("bufferSpatialReference").value });
                  params.outSpatialReference = this.map.spatialReference;
                  params.unit = GeometryService[dom.byId("unit").value];
                  params.unionResults = true;
                  params.geometries = [feature.geometry];
                  if (type === "polygon") {
                      require(["esri/tasks/AreasAndLengthsParameters", "esri/tasks/GeometryService",
                      ], function(AreasAndLengthsParameters, GeometryService) {
                          var areasAndLengthParams = new AreasAndLengthsParameters();
                          areasAndLengthParams.lengthUnit = GeometryService.UNIT_FOOT;
                          areasAndLengthParams.areaUnit = GeometryService.UNIT_ACRES;
                          gsvc.simplify([feature.geometry], function (simplifiedGeometries) {
                              areasAndLengthParams.polygons = simplifiedGeometries;
                              gsvc.areasAndLengths(areasAndLengthParams);
                          });

                      });

                      gsvc.buffer(params, lang.hitch(this, this._showBuffer),
                            function (err) {
                                alert("Query " + err);
                            });

Thanks

Re: The issue is unionResults seems not working.

RiyasDeen — Thu, 04 Sep 2014 12:51:43 GMT

Hi Zhan,

I suspect the code you posted is within a for loop where you are iterating through your features.

If my suspicion is correct, you are actually hitting three individual buffer requests one for each feature. In this case there is nothing to union, as there is only one buffered geometry for each feature.

You may want to consolidate all your feature geometries within the loop as an array and call buffer from outside the loop.

Re: The issue is unionResults seems not working.

RobertScheitlin__GISP — Thu, 04 Sep 2014 13:02:04 GMT

Zhan,

I would have to see more of your code, but it appears that you are actually buffering each of your individual geometries separately and not giving the buffer params an array of all your geometries:

params.geometries = [feature.geometry];

Re: The issue is unionResults seems not working.

ZhanGao — Thu, 04 Sep 2014 15:48:12 GMT

Hi, Robert

here is whole module:

_drawResults: function (layerIndex, results) {
var currentLayer = this.resultLayers[layerIndex];
var features = results.features;

              for (var i = 0, len = features.length; i < len; i++) {
                  var feature = features;
                  var listItem = this.list.items;
                  var type = feature.geometry.type;
                  var geometry, symbol, centerpoint;
                  switch (type) {
                      case "multipoint":
                      case "point":
                          if (this.config.symbols && this.config.symbols.simplemarkersymbol) {
                              symbol = new SimpleMarkerSymbol(this.config.symbols.simplemarkersymbol);
                          } else {
                              if (this.config.symbols && this.config.symbols.picturemarkersymbol) {
                                  symbol = new PictureMarkerSymbol(this.config.symbols.picturemarkersymbol);
                              }
                              else {
                                  symbol = new SimpleMarkerSymbol();
                              }
                          }
                          centerpoint = feature.geometry;
                          break;
                      case "polyline":
                          if (this.config.symbols && this.config.symbols.simplelinesymbol) {
                              symbol = new SimpleLineSymbol(this.config.symbols.simplelinesymbol);
                          } else {
                              symbol = new SimpleLineSymbol();
                          }
                          centerpoint = feature.geometry.getPoint(0, 0);
                          break;
                      case "extent":
                      case "polygon":
                          if (this.config.symbols && this.config.symbols.simplefillsymbol) {
                              symbol = new SimpleFillSymbol(this.config.symbols.simplefillsymbol);
                          } else {
                              symbol = new SimpleFillSymbol();
                          }
                          centerpoint = feature.geometry.getPoint(0, 0);
                          break;
                      default:
                          break;
                  }

                  listItem.centerpoint = centerpoint;
                  listItem.graphic = feature;
                  var title = listItem.title;
                  var content = listItem.content;
                  if (!feature.symbol) {
                      feature.setSymbol(symbol);
                  }
                  if (!feature.infoWindow) {
                      var it = new InfoTemplate(title, title + "<br>" + content);
                      feature.setInfoTemplate(it);
                  }
                  currentLayer.add(feature);

                  //Do buffer.
                  var gsvc, tb, poline;
                  gsvc = new GeometryService("https://xxxx.com/arcgis/rest/services/Utilities/Geometry/GeometryServer");
                  esriConfig.defaults.io.proxyUrl = "/proxy";
                  esriConfig.defaults.io.alwaysUseProxy = false;

                  switch (type) {
                      case "point":
                          var symbol = new SimpleMarkerSymbol(SimpleMarkerSymbol.STYLE_SQUARE, 10, new SimpleLineSymbol(SimpleLineSymbol.STYLE_SOLID, new Color([255, 0, 0]), 1), new Color([0, 255, 0, 0.25]));
                          break;
                      case "polyline":
                          var symbol = new SimpleLineSymbol(SimpleLineSymbol.STYLE_DASH, new Color([255, 0, 0]), 1);
                          break;
                      case "polygon":
                          var symbol = new SimpleFillSymbol(SimpleFillSymbol.STYLE_NONE, new SimpleLineSymbol(SimpleLineSymbol.STYLE_DASHDOT, new Color([255, 0, 0]), 2), new Color([255, 255, 0, 0.25]));
                          break;
                  }

var graphic = new Graphic(feature.geometry, symbol)

this.map.graphics.add(graphic);
}

                  gsvc.buffer(params, lang.hitch(this, this._showBuffer),
                        function (err) {
                            alert("Query " + err);
                        });
              }
          },

Thanks again.

Re: The issue is unionResults seems not working.

RobertScheitlin__GISP — Thu, 04 Sep 2014 18:30:34 GMT

Zhan,

Something more like this would be what you are after:

       _drawResults: function (layerIndex, results) {
          var currentLayer = this.resultLayers[layerIndex];
          var features = results.features;
//added GeomArray
          var GeomArray = [];
//end add
          for (var i = 0, len = features.length; i < len; i++) {
              var feature = features;
              var listItem = this.list.items;
              var type = feature.geometry.type;
              var geometry, symbol, centerpoint;
            
              switch (type) {
                  case "multipoint":
                  case "point":
                      if (this.config.symbols && this.config.symbols.simplemarkersymbol) {
                          symbol = new SimpleMarkerSymbol(this.config.symbols.simplemarkersymbol);
                      } else {
                          if (this.config.symbols && this.config.symbols.picturemarkersymbol) {
                              symbol = new PictureMarkerSymbol(this.config.symbols.picturemarkersymbol);
                          }
                          else {
                              symbol = new SimpleMarkerSymbol();
                          }
                      }
                      centerpoint = feature.geometry;
                      break;
                  case "polyline":
                      if (this.config.symbols && this.config.symbols.simplelinesymbol) {
                          symbol = new SimpleLineSymbol(this.config.symbols.simplelinesymbol);
                      } else {
                          symbol = new SimpleLineSymbol();
                      }
                      centerpoint = feature.geometry.getPoint(0, 0);
                      break;
                  case "extent":
                  case "polygon":
                      if (this.config.symbols && this.config.symbols.simplefillsymbol) {
                          symbol = new SimpleFillSymbol(this.config.symbols.simplefillsymbol);
                      } else {
                          symbol = new SimpleFillSymbol();
                      }
                      centerpoint = feature.geometry.getPoint(0, 0);
                      break;
                  default:
                      break;
              }

              listItem.centerpoint = centerpoint;
              listItem.graphic = feature;
              var title = listItem.title;
              var content = listItem.content;
              if (!feature.symbol) {
                  feature.setSymbol(symbol);
              }
              if (!feature.infoWindow) {
                  var it = new InfoTemplate(title, title + "<br>" + content);
                  feature.setInfoTemplate(it);
              }
              currentLayer.add(feature);

              //Do buffer.
              var gsvc, tb, poline;
              gsvc = new GeometryService("https://xxxx.com/arcgis/rest/services/Utilities/Geometry/GeometryServer");
              esriConfig.defaults.io.proxyUrl = "/proxy";
              esriConfig.defaults.io.alwaysUseProxy = false;

              switch (type) {
                  case "point":
                      var symbol = new SimpleMarkerSymbol(SimpleMarkerSymbol.STYLE_SQUARE, 10, new SimpleLineSymbol(SimpleLineSymbol.STYLE_SOLID, new Color([255, 0, 0]), 1), new Color([0, 255, 0, 0.25]));
                      break;
                  case "polyline":
                      var symbol = new SimpleLineSymbol(SimpleLineSymbol.STYLE_DASH, new Color([255, 0, 0]), 1);
                      break;
                  case "polygon":
                      var symbol = new SimpleFillSymbol(SimpleFillSymbol.STYLE_NONE, new SimpleLineSymbol(SimpleLineSymbol.STYLE_DASHDOT, new Color([255, 0, 0]), 2), new Color([255, 255, 0, 0.25]));
                      break;
              }


              var graphic = new Graphic(feature.geometry, symbol);
//Add the features geometry to the array
              GeomArray.push(feature.geometry);
//end add
              this.map.graphics.add(graphic);
          }

          var params = new BufferParameters();
          params.distances = [dom.byId("distance").value];
          params.bufferSpatialReference = new esri.SpatialReference({ wkid: dom.byId("bufferSpatialReference").value });
          params.outSpatialReference = this.map.spatialReference;
          params.unit = GeometryService[dom.byId("unit").value];
          params.unionResults = true;
          params.geometries = GeomArray; //set the buffer params geometries to the GeomArray
          if (type === "polygon") {
              //if geometry is a polygon then simplify polygon.  This will make the user drawn polygon topologically correct.
              gsvc.buffer(params, lang.hitch(this, this._showBuffer),
                    function (err) {
                        alert("Query " + err);
                    });
          } else {

              gsvc.buffer(params, lang.hitch(this, this._showBuffer),
                    function (err) {
                        alert("Query " + err);
                    });
          }
      },

Re: The issue is unionResults seems not working.

ZhanGao — Thu, 04 Sep 2014 18:37:52 GMT

Thanks Robert,

I figure out the solution, here the code I add to create polygon.

polygon = new Polygon(this.map.spatialReference);
              for (i = 0; i < graphic._graphicsLayer.graphics.length; i++) {
                  ringsLength = graphic.geometry.rings.length;
                  if (this.map.graphics.graphics.geometry.type == "polygon") {
                      for (j = 0; j < ringsLength; j++) {
                          polygon.addRing(this.map.graphics.graphics.geometry.rings);
                      }
                  }
              }

                  gsvc.buffer(params, lang.hitch(this, this._showBuffer),
                        function (err) {
                            alert("Query " + err);
                        });
              }

Re: The issue is unionResults seems not working.

RobertScheitlin__GISP — Fri, 05 Sep 2014 13:22:53 GMT

Zhan,

Your method is working because to are manually merging the the polygons client side instead of allowing the Server to buffer all the geometries at once and then merge them server side as my code shows. Either way can you mark this thread as answered so that people can find the correct answer. Do this my clicking the "Correct Answer" link (with the little green star) on your reply or mine.

Re: The issue is unionResults seems not working.

ZhanGao — Fri, 05 Sep 2014 13:51:30 GMT

Hi Robert,

we need to check if geometry type is polygon then add feature geometry to the array.

if (feature.geometry.type == "polygon") {

bufferGeometry.push(feature.geometry)

}