topic Re: How to change (shrink) a polygon used to intersect another layer in the eSearch widget? in Web AppBuilder Custom Widgets Questions

How to change (shrink) a polygon used to intersect another layer in the eSearch widget?

DouglasGuess — Thu, 19 Sep 2019 16:06:55 GMT

I'm using Robert's eSearch widget and I'm trying to use a selected polygon to intersect another layer; however, I need to "shrink" the original polygon so the new polygon used to perform the intersection is fully contained within the original selected polygon. I've tried to take the original selected polygon rings and subtract a value of 50 from each x,y pair, however, that just resulted in shifting the temp polygon and not actually "shrinking" it. Any suggestions or help would be greatly appreciated!

Re: How to change (shrink) a polygon used to intersect another layer in the eSearch widget?

RobertScheitlin__GISP — Thu, 19 Sep 2019 16:39:47 GMT

Douglas,

You can switch to the by spatial and use a negative number in the buffer to do your selection by.

Re: How to change (shrink) a polygon used to intersect another layer in the eSearch widget?

DouglasGuess — Thu, 19 Sep 2019 16:56:16 GMT

Thanks for the reply Robert. However, I need to perform this intersection right after the parcel selection takes places and before the results are displayed. So, are you saying I can apply a negative buffer and use that as the intersection with another layer? I'll take a look at your Spatial tab code and see if I can call that before the results are displayed. Do you have some thoughts or suggestions on how to accomplish this?

Re: How to change (shrink) a polygon used to intersect another layer in the eSearch widget?

RobertScheitlin__GISP — Thu, 19 Sep 2019 17:15:24 GMT

Douglas,

So, are you saying I can apply a negative buffer and use that as the intersection with another layer?

Correct.

You could change the spatial relationship in the eSearch queryTask code to be contains instead of intersects too.

Re: How to change (shrink) a polygon used to intersect another layer in the eSearch widget?

DouglasGuess — Fri, 20 Sep 2019 14:28:42 GMT

Robert.

I'm having an issue when calling the _bufferGeometries function. I need it to complete the geometryService buffer event before continuing through the rest of my code because I need the buffered graphic geometry. How can I force the esriConfig.defaults.geometryService.buffer() event to complete before moving on through the rest of my function?

Re: How to change (shrink) a polygon used to intersect another layer in the eSearch widget?

RobertScheitlin__GISP — Fri, 20 Sep 2019 14:35:46 GMT

Douglas,

The buffer method returns a deferred. So just listen for buffer complete event.

Re: How to change (shrink) a polygon used to intersect another layer in the eSearch widget?

DouglasGuess — Fri, 20 Sep 2019 14:50:05 GMT

Robert,

That did the trick. Thanks!

Re: How to change (shrink) a polygon used to intersect another layer in the eSearch widget?

DouglasGuess — Mon, 23 Sep 2019 22:10:35 GMT

Hi Robert,

Not sure if you're still following this thread but I thought I had things worked out, turned out I was wrong. What I'm trying to do is within the _onSearchFinish function, instead of calling the _drawResults function, I'm calling a custom _doSpatialQuery function. Within this function I'm looping through the selection results (parcels) and it's here where I need get the buffer (negative distance) of each result and then use that buffer geometry as the input to perform the spatial query (intersection) with another layer to build some links within each result. I've attached my modified eSearch widget for reference. I've just been spinning my wheels with this so any help/input would be GREATLY appreciated!

Re: How to change (shrink) a polygon used to intersect another layer in the eSearch widget?

RobertScheitlin__GISP — Tue, 24 Sep 2019 13:31:47 GMT

Douglas,

Are you using a standard esri basemap or are you using a custom one that would put the maps WKID other than 102100 (webmercator)?

Re: How to change (shrink) a polygon used to intersect another layer in the eSearch widget?

DouglasGuess — Tue, 24 Sep 2019 13:48:05 GMT

I'm using a custom basemap where the data is in Nebraska State Plane NAD83 and the service is published in Web Mercator. So, the map spatial reference WKID should be 102100.

Re: How to change (shrink) a polygon used to intersect another layer in the eSearch widget?

DouglasGuess — Tue, 24 Sep 2019 13:54:26 GMT

I think I might have a resolution but I need to pass each original search results data (qResult data) into each of the selection buffered polygons. Once I have that, I should be able to loop through each buffered poly and intersection that with my quarter quarter section layer to build the link url. Any thoughts on how to pass the qResults into the buffered poly?

Re: How to change (shrink) a polygon used to intersect another layer in the eSearch widget?

RobertScheitlin__GISP — Tue, 24 Sep 2019 14:07:14 GMT

Douglas,

The buffer results will always return in the same order that they are submitted. So you just replace the original graphics (which has the attributes data) geometry with the resultant buffer geometry.

Re: How to change (shrink) a polygon used to intersect another layer in the eSearch widget?

DouglasGuess — Tue, 24 Sep 2019 14:54:29 GMT

So, something like this...

this.buffArray = buffGeometries;
for (b = 0; b < this.buffArray.length; b++){
    for (q = 0; q < this.qResults.length; q++){
         this.qResults.geometry.rings = this.buffArray.rings;
    }
}

Re: How to change (shrink) a polygon used to intersect another layer in the eSearch widget?

RobertScheitlin__GISP — Tue, 24 Sep 2019 15:07:35 GMT

Yes but no need to go to the ring level.

this.qResults.geometry = buffGeometries;

Re: How to change (shrink) a polygon used to intersect another layer in the eSearch widget?

DouglasGuess — Tue, 24 Sep 2019 15:24:36 GMT

Ok, that makes sense. If there are multiple selected results, the buffer geometries returns only the first item. I thought the ".then" of the geometryService.buffer acts like a promise and should wait until all geometries are returned. How can I send both buffered results to the _doSpatialQuery function?

var unit = "UNIT_FOOT";
var dist = [parseFloat(-15)];
var bufferParameters = new BufferParameters();
var resultEvent;
var geoms = array.map(this.currentLayerAdded.graphics, function (gra) { //** 2 Results
return gra.geometry;
});

bufferParameters.geometries = geoms;
bufferParameters.bufferSpatialReference = this.map.spatialReference;
bufferParameters.unit = GeometryService[unit];
bufferParameters.distances = dist;
bufferParameters.unionResults = true;
bufferParameters.geodesic = true;
bufferParameters.outSpatialReference = this.map.spatialReference;

esriConfig.defaults.geometryService.buffer(bufferParameters)
.then(lang.hitch(this, this._doSpatialQuery));

_doSpatialQuery: function(buffGeometries){       //** only 1 result in buffGeometries
   // Replace original selected poly geometry with buffered geometry
   for (b = 0; b < buffGeometries.length; b++){
      for (q = 0; q < this.queryResultsArray.length; q++){
         this.queryResultsArray.geometry = buffGeometries;
      }
   }

continue with function......

Re: How to change (shrink) a polygon used to intersect another layer in the eSearch widget?

RobertScheitlin__GISP — Tue, 24 Sep 2019 15:33:21 GMT

Douglas,

Because you have the buffer set to unionResults you will only get on geometry back a union of the two parcels buffered.

Re: How to change (shrink) a polygon used to intersect another layer in the eSearch widget?

DouglasGuess — Tue, 24 Sep 2019 15:43:36 GMT

Ahhhh.... Thanks Robert. Sometimes an extra set of eyes always helps.

Thanks again for ALL your help!!!