topic Re: Feature layer query in ArcGIS JavaScript Maps SDK Questions

Feature layer query

deleted-user-x7XmeRtVHyGE — Thu, 07 Jan 2016 04:03:51 GMT

Hello all,

I'm looking for some strategic advice and sample code if possible.

I'm working with a few very large feature services. We are serving these out to a web-based app. Layer1 is a polygon layer and Layer2 is a line layer, with those lines falling within the polygons in Layer1.

Right now our application passes an ID to Layer1 that we then use Layer1.setDefinitionExpression() to segment the data. Now we need to take that boundary and use it to query and display the data from Layer2 where it is within the subset of Layer1.

Any advice on how to proceed? Feature services are necessary for both because of the need for editing.

Enjoy the day,

Mike

Re: Feature layer query

ChrisSmith7 — Thu, 07 Jan 2016 05:24:21 GMT

You might want to check out esri/geometry/geometryEngineAsync | API Reference | ArcGIS API for JavaScript

There are quite a few overlay tools, depending on your needs, you can call directly on the client-side now to extract the features of layer2 using boundary from layer1.

Re: Feature layer query

RobertScheitlin__GISP — Thu, 07 Jan 2016 14:07:46 GMT

Michael,

Based on you using an ID to set the DefinitionExpression of Layer1 it sounds like this is a single polygon. If that is the case then you can simply get the geometry of the ID using FeatureLayer queryFeatures and then use that geometry as the Query.geometry and then Query Layer 2 using selectFeatures method. If it is more than on feature in Layer1 then you would use geometryEngine Union to union the features geometries first and then use that unioned geometry to do the selectFeatures on Layer2.

Re: Feature layer query

deleted-user-x7XmeRtVHyGE — Thu, 07 Jan 2016 15:05:31 GMT

Robert and Chris,

As always, thanks for the guidance. I'm trying to implement and am stuck a bit now. Here is a snip of the code I'm using. I think this is on track, but I'm getting ReferenceError: featureSet is not defined. Any clue where I'm going wrong?

featureLayer.setDefinitionExpression("EntityID = 11828");

var geom = new Polygon(featureLayer);

var query = new Query();

query.where = "EntityID = 11828";

pondLayer.queryFeatures(query, function(featureset){

for (var i = 0; i < featureSet.features.geometry; i ) {

var feature = featureSet.features;};

geometryEngineAsync.union(feature);

var query2 = new Query();

query2.geometry = feature.geometry;

query2.spatialRelationship = Query.SPATIAL_REL_CONTAINS;

pondLayer.selectFeatures(query2, FeatureLayer.SELECTION_NEW)

})

//query.spatialRelationship = Query.SPATIAL_REL_ENVELOPEINTERSECTS;

//query.returnGeometry = true;

//query.outFields = ["*"];

//auto zoom

dojo.connect(featureLayer, "onUpdateEnd", function () {

var zoomExtent = esri.graphicsExtent(featureLayer.graphics);

map.setExtent(zoomExtent, true);

});

map.addLayers([featureLayer, pondLayer]);

Re: Feature layer query

KenBuja — Thu, 07 Jan 2016 15:08:53 GMT

You're declaring "featureset" in the queryFeatures function but then use "featureSet". JavaScript is case sensitive.

Re: Feature layer query

deleted-user-x7XmeRtVHyGE — Thu, 07 Jan 2016 15:15:48 GMT

OK. Now I'm at this point, but I receive the following error: TypeError: a is undefined. Any clue?

Sorry if this is elementary.

var geom = new Polygon(featureLayer);

var query = new Query();

query.where = "EntityID = 11828";

pondLayer.queryFeatures(query, function(featureset){

for (var i = 0; i < featureset.features.geometry; i ) {

var feature = featurset.features;};

geometryEngineAsync.union(feature);

var query2 = new Query();

query2.geometry = feature.geometry;

query2.spatialRelationship = Query.SPATIAL_REL_CONTAINS;

pondLayer.selectFeatures(query2, FeatureLayer.SELECTION_NEW)

})

Re: Feature layer query

deleted-user-x7XmeRtVHyGE — Thu, 07 Jan 2016 15:21:25 GMT

OK. Now I'm at this point, but I receive the following error: TypeError: a is undefined. Any clue?

Sorry if this is elementary.

var geom = new Polygon(featureLayer);

var query = new Query();

query.where = "EntityID = 11828";

pondLayer.queryFeatures(query, function(featureset){

for (var i = 0; i < featureset.features.geometry; i ) {

var feature = featurset.features;};

geometryEngineAsync.union(feature);

var query2 = new Query();

query2.geometry = feature.geometry;

query2.spatialRelationship = Query.SPATIAL_REL_CONTAINS;

pondLayer.selectFeatures(query2, FeatureLayer.SELECTION_NEW)

})

Re: Feature layer query

RobertScheitlin__GISP — Thu, 07 Jan 2016 15:55:48 GMT

Michael,

How many features doe you have coming back from the query.where = "EntityID = 11828"? If it is only one feature is the polygon then you do not need the union.

Re: Feature layer query

deleted-user-x7XmeRtVHyGE — Thu, 07 Jan 2016 15:58:52 GMT

We have 4 features returned from that EntityID. Overall it varies though, from 1 to ~15, depending on the EntityID.

Thanks, Robert.

I'll need to get you a beer at the User Conference this year!

Re: Feature layer query

RobertScheitlin__GISP — Sat, 11 Dec 2021 18:21:39 GMT

Michael,

Something more like this:

var geoms = [];
pondLayer.queryFeatures(query, function(featureset){
    for (var i = 0; i < featureset.features.length; i++) {
        var feature = featurset.features;
        geoms.push(feature);
    })
    var union = geometryEngine.uniongeoms(geoms); //Notice I am using geometryEngine and not geometryEngineAsync
    var query2 = new Query();
    query2.geometry = union;
    query2.spatialRelationship = Query.SPATIAL_REL_CONTAINS;
    pondLayer.selectFeatures(query2, FeatureLayer.SELECTION_NEW);
});

Edited!! based on Kens catch.

Re: Feature layer query

KenBuja — Sat, 11 Dec 2021 18:21:41 GMT

Robert Scheitlin,

Why isn't the union and second selection section within the queryFeatures function? Wouldn't those happen before the queryFeatures function completes?

var geoms = [];  
pondLayer.queryFeatures(query, function(featureset){  
    for (var i = 0; i < featureset.features.length; i++) {  
        var feature = featurset.features;  
        geoms.push(feature);  
    })  
    var union = geometryEngine.uniongeoms(geoms); //Notice I am using geometryEngine and not geometryEngineAsync  
    var query2 = new Query();  
    query2.geometry = union;  
    query2.spatialRelationship = Query.SPATIAL_REL_CONTAINS;  
    pondLayer.selectFeatures(query2, FeatureLayer.SELECTION_NEW);  
});

Re: Feature layer query

RobertScheitlin__GISP — Thu, 07 Jan 2016 17:17:52 GMT

Ken,

You are correct.

Re: Feature layer query

deleted-user-x7XmeRtVHyGE — Thu, 07 Jan 2016 21:08:18 GMT

Thanks Robert and Ken. I'm seeing light at the end of the tunnel. Now I'm getting a TypeError that refers back to the geometryEngine saying "c.getCacheValue is not a function". I'm assuming I may have the wrong references (currently referencing 3.13)?

var geoms = [];

pondLayer.queryFeatures(query, function(featureSet){

for (var i = 0; i < featureSet.features.length; i++) {

var feature = featureSet.features;

geoms.push(feature);

};

var union = geometryEngine.union(geoms); //Notice I am using geometryEngine and not geometryEngineAsync

var query2 = new Query();

query2.geometry = union;

query2.spatialRelationship = Query.SPATIAL_REL_CONTAINS;

pondLayer.selectFeatures(query2, FeatureLayer.SELECTION_NEW);

});

Re: Feature layer query

RobertScheitlin__GISP — Thu, 07 Jan 2016 21:10:54 GMT

Michael,

Correct the geometryEngine did not come out of Beta until 3.15, so just use 3.15.

Re: Feature layer query

deleted-user-x7XmeRtVHyGE — Thu, 07 Jan 2016 21:46:23 GMT

c.getCacheValue is not a function still persists after switching to 3.15 and points to the geometryEngine. I'm going to keep digging, but I'm not finding an obvious solution. Any other ideas?

Thanks for all your help. Very appreciated.

Re: Feature layer query

RobertScheitlin__GISP — Thu, 07 Jan 2016 21:59:47 GMT

Michael,

Is it possible to zip-up all your code and attach it to a reply (use the advance editor to get the attach option).

Re: Feature layer query

deleted-user-x7XmeRtVHyGE — Thu, 07 Jan 2016 22:39:24 GMT

Robert,

Here is the full html file for the page. Thanks for all your help again.

Enjoy the day,

Mike

Re: Feature layer query

RobertScheitlin__GISP — Sat, 11 Dec 2021 18:21:45 GMT

Michael,

Try this:

You need to add the features geometry and not just the feature to the geoms array.

function queryGo() {
        var query = new Query();
        query.where = "EntityID = 11828";
        query.outfields = ["*"];
        query.returnGeometry = true;
        query.spatialReference = sr;
        query.outSpatialReference = sr;
        var geoms = [];
        var union;
        //geoms.SpatialReference = sr;
        featureLayer.queryFeatures(query, function (featureSet) {
          for (var i = 0; i < featureSet.features.length; i++) {
            var feature = featureSet.features;
            geoms.push(feature.geometry);
          }
          union = geometryEngine.union(geoms);
          //console.log(union);
          var query2 = new Query();
          query2.geometry = union;
          query2.spatialRelationship = Query.SPATIAL_REL_CONTAINS;
          pondLayer.selectFeatures(query2, FeatureLayer.SELECTION_NEW);
        });
      }

Re: Feature layer query

deleted-user-x7XmeRtVHyGE — Fri, 08 Jan 2016 16:15:57 GMT

Hi Robert,

This is working great for me right now. I see the array of the unioned features, but I can't get the selected features to show now. Any ideas on why that may be? Thank you so much for your help.

Enjoy the day,

Mike

Re: Feature layer query

deleted-user-x7XmeRtVHyGE — Fri, 08 Jan 2016 16:59:26 GMT

Hi Robert,

A little more digging on this. When I get the count of features selected by Query2 run against the pondLayer it returns all features in the database. Not sure if I'm missing a query parameter?

Enjoy the day,

Mike