topic Re: .setDefinitionExpression using geometry? in ArcGIS JavaScript Maps SDK Questions

.setDefinitionExpression using geometry?

JamesCrandall — Sat, 11 Dec 2021 18:03:15 GMT

Probably multiple ways to handle this, but I need to set a definition expression on a polygon FeatureLayer using the intersection of another polygon FeatureLayer. I had been simply using a WHERE clause on an attribute, but the requirement has changed to use the geometry from a different FeatureLayer.

Any help is appreciated.

What I have so far:

createFuncLocLayer: function () {
      this.funcLocLayer = new FeatureLayer(this.config.functionalLocationLayer);
      this.workplanBoundaryLayer.queryFeatures(this.queryWorkplanLayer(), lang.hitch(this, function (result) {
        var wpGeometry = geometryEngine.geodesicBuffer(result.features[0].geometry, -20, "meters")
        
        //How can I apply this.funcLocLayer.setDefinitionExpression to use the wpGeometry variable?

      }));‍‍‍‍‍‍‍‍

Re: .setDefinitionExpression using geometry?

RobertScheitlin__GISP — Sat, 11 Dec 2021 18:03:18 GMT

James,

You can not use a Geometry in a layers definition expression. What you have to do is turn that geometry into a sql expression. So you use the geometry to query the OIDs of the layer that intersect (or what ever spatial relationship you want) and then send that array of ObjectIds to the layer definition expression.

createFuncLocLayer: function () {
  this.funcLocLayer = new FeatureLayer(this.config.functionalLocationLayer);
  this.workplanBoundaryLayer.queryFeatures(this.queryWorkplanLayer(), lang.hitch(this, function (result) {
    var wpGeometry = geometryEngine.geodesicBuffer(result.features[0].geometry, -20, "meters");
    var query = new Query();
    query.geometry = wpGeometry;
    ...
    //Add other necessary query prperties such as spatial relationship
    this.funcLocLayer.queryIds(query, lang.hitch(this,function(objectIds) {
      var qStr = this.funcLocLayer.objectIdField + " IN(" +objectIds.join(',') + ")";
      this.funcLocLayer.setDefinitionExpression(qStr ); 
    });
  }));
...
}‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: .setDefinitionExpression using geometry?

JamesCrandall — Tue, 29 May 2018 14:25:51 GMT

hmm. So I will need to first select on funcLocLayer, collect OID's and then use those to setDefinitionExpression on that same FeatureLayer?

Re: .setDefinitionExpression using geometry?

RobertScheitlin__GISP — Tue, 29 May 2018 14:43:33 GMT

James,

Maybe you better explain your workflow.

Re: .setDefinitionExpression using geometry?

JamesCrandall — Tue, 29 May 2018 14:50:21 GMT

I have two polygon Feature Layers:

FeatureLayer1 always has a single(1) polygon feature.
FeatureLayer2 has thousands of polygon features.

Requirement: Apply definition query/expression to FeatureLayer2 so that the only features available (throughout the entire session) in the map are those that intersect with the single polygon in FeatureLayer1.

Re: .setDefinitionExpression using geometry?

RichardReinicke — Sat, 11 Dec 2021 18:03:21 GMT

Hi James,

I haven't tried this out but I think you have to use FeatureLayerView or execute a query on the FeatureLayer and create a layer for visualization from the results?

FeatureLayerView | API Reference | ArcGIS API for JavaScript 4.7

var query = new Query({
   geometry: wpGeometry,
   spatialRelationship = "intersects"
});

// YOU CAN USE LAYERVIEW WHICH YOU CAN USE TO HOOK INTO LAYERS UPDATE EVENT

view.whenLayerView(this.funcLocLayer).then(function(lyrView){
  lyrView.watch("updating", function(val){
    if(!val){  // wait for the layer view to finish updating
      lyrView.queryFeatures(query).then(function(results){
        // Do additional stuff
      });
    }
  });
});‍‍‍‍‍‍‍‍‍‍‍‍‍‍

// OR USE THE QUERY DIRECLY ON THE LAYER

this.funcLocLayer.queryFeatures(query).then(function(results){
  // Create the final layer and add to map or update an existing layer
});‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Let me know if this helps.

Re: .setDefinitionExpression using geometry?

RobertScheitlin__GISP — Tue, 29 May 2018 16:01:25 GMT

James since FeatureLayer1 will only ever have on Polygon you don't really need a query for that. Just make sure FeatureLayer1 is loaded and grab the first graphic.

i.e.

var geom = FeatureLayer1.graphics[0];‍

Then run a query on FeatureLayer2 using the geom from the previous as mentioned earlier and then apply the definition query to FeatureLayer2.

Re: .setDefinitionExpression using geometry?

JamesCrandall — Tue, 29 May 2018 16:58:32 GMT

Good point.

Re: .setDefinitionExpression using geometry?

JamesCrandall — Tue, 29 May 2018 20:26:27 GMT

It's very unclear to me how to .execute on the queryTask without having to jump to another showResult function. Also, I haven't found how to replace the query.where with a query.geometry property.

Do you have any examples of querying with the geometry?

Re: .setDefinitionExpression using geometry?

RobertScheitlin__GISP — Sat, 11 Dec 2021 18:03:23 GMT

James,

A Query class has a where property and a geometry property. You may be use to using the where but you can also just use the geometry property instead or or in addition to the where property.

createFuncLocLayer: function () {
  this.funcLocLayer = new FeatureLayer(this.config.functionalLocationLayer);
  var def = new Deferred();
  if(!this.workplanBoundaryLayer.loaded){
    this.workplanBoundaryLayer.on("load" lang.hitch(this, function(){
      def.resolve(this.workplanBoundaryLayer.graphics[0]);
    }));
  }else{
    def.resolve(this.workplanBoundaryLayer.graphics[0]);
  }
  def.then(lang.hitch(this, function(result){
    var geom = result;
    var wpGeometry = geometryEngine.geodesicBuffer(geom, -20, "meters");
    var query = new Query();
    query.outFields = ["*"];
    query.returnGeometry = true;
    query.outSpatialReference = this.map.spatialReference;
    query.geometry = wpGeometry;
    this.funcLocLayer.queryIds(query, lang.hitch(this,function(objectIds) {
      var qStr = this.funcLocLayer.objectIdField + " IN(" +objectIds.join(',') + ")";
      this.funcLocLayer.setDefinitionExpression(qStr ); 
    });
  }));
...
}‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: .setDefinitionExpression using geometry?

JamesCrandall — Wed, 30 May 2018 12:57:42 GMT

Thank you for that!

I never would have thought to implement what you did there with the Deferred. So many unknowns. Overwhelming really.

Is there an ending ")" missing for this?

this.workplanBoundaryLayer.on("load" lang.hitch(this, function(){

I get an "expected ;" error here on the second ")":

if(!this.workplanBoundaryLayer.loaded){

this.workplanBoundaryLayer.on("load" lang.hitch(this, function(){

def.resolve(this.workplanBoundaryLayer.graphics[0]);

})); //error on this line says "expected ;"

}else{

def.resolve(this.workplanBoundaryLayer.graphics[0]);

}

Re: .setDefinitionExpression using geometry?

RobertScheitlin__GISP — Wed, 30 May 2018 13:03:11 GMT

James,

I forgot the comma after the "load".

this.workplanBoundaryLayer.on("load", lang.hitch(this, function(){

Re: .setDefinitionExpression using geometry?

JamesCrandall — Wed, 30 May 2018 13:35:47 GMT

I don't know how I missed that.

Thank you

Re: .setDefinitionExpression using geometry?

JamesCrandall — Sat, 11 Dec 2021 18:03:26 GMT

Robert -- I'm marking as correct cause I don't doubt this is what I need to implement. Still working thru a problem of "result" = undefined and causing an issue setting the wpGeometry var. I'll see if what I'm doing wrong there.

def.then(lang.hitch(this, function(result){
                debugger
                if (result) {
                    var geom = result;
                    var wpGeometry = geometryEngine.geodesicBuffer(geom, -20, "meters");
                    var query = new Query();
                    query.outFields = ["*"];
                    query.returnGeometry = true;
                    query.outSpatialReference = this.map.spatialReference;
                    query.geometry = wpGeometry;
                    debugger
                    this.funcLocLayer.queryIds(query, lang.hitch(this, function (objectIds) {
                        var qStr = this.funcLocLayer.objectIdField + " IN(" + objectIds.join(',') + ")";
                        this.funcLocLayer.setDefinitionExpression(qStr);
                    }));
                }‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: .setDefinitionExpression using geometry?

JamesCrandall — Wed, 30 May 2018 19:51:48 GMT

Robert,

Thanks again!

I was struggling with making your solution/suggestion error-free and found the issue (pretty typical struggle for me, not sure how else to pick these out faster, I think I'm getting a bit better tho). It finally makes it to qStr and I believe sets the definitionExpression as desired:

var geom = result;‍

Should be

var geom = result.geometry;‍

Re: .setDefinitionExpression using geometry?

RobertScheitlin__GISP — Wed, 30 May 2018 21:27:03 GMT

James,

Sorry about that. The returned value from the deferred was a graphic and you where needing a geometry.