topic Re: GeometryEngine 3.15 union error when using try-catch in ArcGIS JavaScript Maps SDK Questions

GeometryEngine 3.15 union error when using try-catch

AndrewBiggins — Sun, 12 Dec 2021 01:16:25 GMT

I have tried the GeometryEngine.union method (within JavaScript 3.15 API) but it throws the following error when it is placed within a try-catch statement:

TypeError: Unable to get property 'hq' of undefined or null reference

It seems to work when not placed within a try-catch, but since it is throwing this error I'm concerned about using it within a production application. Also, the equivalent Union method in the ArcGIS Server GeometryService does not throw an error.

I thought the error might be due to undefined spatial references in the array of geometries passed to it, but I have checked and they are all defined.

Can anyone please advise why this error is being thrown?

arrayUtils.forEach(AdviceGlobal.savedFeaturesGraphicsLayer.graphics, function (savedGraphic) {
 // Define spatial reference for geometryEngine
 var thisGeometry = savedGraphic.geometry;
 console.log(thisGeometry.spatialReference);
 if (thisGeometry.spatialReference == null) {
  thisGeometry.spatialReference = map.spatialReference;
 }
 geometryToCapture.push(thisGeometry);
});
// Try geometryEngine
try {
    var unionedGeometry = geometryEngine.union(geometryToCapture);
    saveFeature(unionedGeometry);
}
catch (e) {
    onUnionError(e);
}

Re: GeometryEngine 3.15 union error when using try-catch

JoelBennett — Sun, 12 Dec 2021 01:16:28 GMT

I too have had the same issue, which has been occurring since geometryEngine's introduction in 3.13. I hadn't noticed (and therefore can't verify) the try/catch issue since my code doesn't have any of those clauses around this operation. My code executes the combine operation inside of a callback from a QueryTask, so there's probably a try/catch somewhere up the call stack in the JavaScript API.

Since I'm not the only person this is happening to, I was emboldened to look into this further. Unfortunately, the code for geometryEngine is much too obfuscated to readily understand what's going on, but here's the function where things foul up:

b.prototype.iL=function(a){
 for(var d=[],c=[],h=this.sn,l=b.bc(h),g=0;g<l.length;g++){
  var m=l,n=h;
  if(this.Fc||1E4<n.hq&&1<n.Ci.length){
   this.bp-=n.Ci.length;
   for(this.Qo-=n.Ci.length;0<n.Ci.length;)
    d.push(n.Cv().hw),n.OQ();
   c.push(m)
  }
 }
 for(g=0;g<c.length;g++)
  delete h[c];
 return d
};

The error is thrown when comparing if 1E4 is less than n.hq, and occurs because n is undefined. If we look further up, we see n was set to the value of h...that is, an element of some array. In my case, h was an array with a length of 4, but elements with index 0, 1, and 2 were undefined. However, this code wrongly assumes all the elements in the array it references are defined...hence the error.

I use a locally hosted version of the API, and so I tweaked it a little to check for a valid value of n before proceeding.

Therefore, the original code (which you can ctrl-f to find):

if(this.Fc||1E4<n.hq&&1<n.Ci.length)

became

if((n)&&(this.Fc||1E4<n.hq&&1<n.Ci.length))

This appears to have fixed the problem, although I haven't performed any rigorous testing...as such, if you try this, proceed with caution. Also, if you do, you'll probably need to delete temporary internet files before reloading your app to ensure you get the updated version.

Re: GeometryEngine 3.15 union error when using try-catch

JoelBennett — Fri, 08 Apr 2016 14:58:27 GMT

ESRI did not fix this bug in version 3.16 of the ArcGIS API for JavaScript.

Re: GeometryEngine 3.15 union error when using try-catch

KenDoman — Thu, 07 Jul 2016 16:47:10 GMT

ESRI has not fixed this bug in version 3.17 of the ArcGIS API for JavaScript, either.

Re: GeometryEngine 3.15 union error when using try-catch

SumitZ — Thu, 07 Jul 2016 19:42:56 GMT

Have you tried simplifying the geometry before doing it union?

Before pushing the geometry to array 'geometryToCapture' simplify using geometryEngine and if the result is valid then only consider that geometry for union.

Re: GeometryEngine 3.15 union error when using try-catch

KristianEkenes — Thu, 07 Jul 2016 20:37:07 GMT

This hasn't been fixed because there hasn't been a bug report logged for it. Once somebody logs as a bug it will be looked at and fixed.

Re: GeometryEngine 3.15 union error when using try-catch

JoelBennett — Fri, 29 Jul 2016 17:52:37 GMT

Thanks Ken...I also have confirmed this is still an issue in 3.17.

Re: GeometryEngine 3.15 union error when using try-catch

YohanBienvenue — Wed, 13 Sep 2017 19:23:41 GMT

This still seems to be an issue with 3.21?

I'm trying to do a simple union of two polygons and I get a TypeError at the exact same line as shown above by Joel Bennett. I don't have any try-catch and the spatialReference (32188) is the same for both polygons. I tried geometryEngine.simplify on each of those polygons before doing a union on them, but it didn't help. The union of the GeometryService works fine. What am I doing wrong with geometryEngine.union?

Update: I tried to figure out how I could apply a fix to that problem function at runtime, but it's not accessible from outside geometryEngine. So I ended up doing something similar to Joel Bennet. I recreated my own version of the geometryEngine (I called it app.geometryEngine), replaced the define at the top from esri/geometry/geometryEngine to app/geometryEngine and also added the "if (n)" at the same problem line. Everything seems fine now. Will update if that changes in the future.

Re: GeometryEngine 3.15 union error when using try-catch

JoelBennett — Tue, 16 Jan 2018 23:50:09 GMT

I've missed a few releases, being busy with other things, but have found this is still an issue in 3.23. I haven't tried union this time around, but it happens with buffer. The workaround is still the same, although some variable names have changed.

Look for

if(this.Ec||1E4<u.jq&&1<u.Ci.length)‍

Replace with

if((u)&&(this.Ec||1E4<u.jq&&1<u.Ci.length))‍

Re: GeometryEngine 3.15 union error when using try-catch

ReneRubalcava — Fri, 13 Apr 2018 17:26:38 GMT

Just tested this out with 3.23, 4.6, 3.24, and 4.7 in Chrome, FF, Edge, IE11 and can't repro. Do you have a repro case to test with?

It's possible this was already fixed somewhere along the line. Tried union, buffer, and geodesicBuffer.

Thanks!

Re: GeometryEngine 3.15 union error when using try-catch

OrenGal — Sun, 15 Apr 2018 04:11:49 GMT

I have managed to discover that this is a conflict between the api and 3rd party js.

remove the geoxml3.js script and it works

add it and it fails

version 3.xx https://jsfiddle.net/orengal/k6ssdqcL

version 4.xx https://jsfiddle.net/orengal/ph7oenz7

I am using the workaround of Joel Bennet on both the APIS. Good job Joel!

Re: GeometryEngine 3.15 union error when using try-catch

JoelBennett — Fri, 04 May 2018 17:47:40 GMT

The problem still occurs in version 3.24, using geodesicBuffer this time (see also attached image). I am not using third party modules. The fix appears to be the same:

Look for (note that this was wrapped over two lines in my text editor):

if(this.Pc||1E4<u.Ds&&1<u.Pj.length)‍

Replace with:

if((u)&&(this.Pc||1E4<u.Ds&&1<u.Pj.length))‍

Windows 10, IE 11

Parameters for geodesicBuffer:

geometry (string representation; an actual Polygon instance was passed):

"{"rings":[[[-17579866.91,2431821.3332],[-17579898.065899998,2431640.692400001],[-17579953.4001,2431648.533399999],[-17579955.833,2431635.3517999984],[-17580002.9127,2431644.161800001],[-17580004.8609,2431633.4224999994],[-17580024.7616,2431635.3834000006],[-17580029.1474,2431599.7437999993],[-17580055.357,2431604.640299998],[-17580035.3918,2431736.4585999995],[-17580027.1143,2431788.6972999982],[-17580007.9076,2431902.6317999996],[-17579983.056,2431899.3718999997],[-17579989.3852,2431863.747299999],[-17579983.7298,2431862.969900001],[-17579984.853,2431854.5929999985],[-17579920.7811,2431844.3082999997],[-17579922.2447,2431830.1493999995],[-17579866.91,2431821.3332]]],"spatialReference":{"wkid":102100,"latestWkid":3857}}"

distance: 500

unit: 9002

unionResults: false

Re: GeometryEngine 3.15 union error when using try-catch

KristianEkenes — Fri, 04 May 2018 19:07:33 GMT

To reiterate a response from nearly two years ago, this issue can be vetted and resolved more quickly when reported through Esri's technical support group. If not reported there it may never be looked at in a timely manner. Call support and provide details regarding the problem with your apps, and they will take more time than the JS team can allot to reproduce the issue and log it as a bug.