Feature layer query

deleted-user-x7XmeRtVHyGE · ‎01-06-2016

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

RobertScheitlin__GISP · ‎01-08-2016

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);
        });
      }

View solution in original post

ChrisSmith7 · ‎01-06-2016

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.

RobertScheitlin__GISP · ‎01-07-2016

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.

deleted-user-x7XmeRtVHyGE · ‎01-07-2016

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]);

KenBuja · ‎01-07-2016

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

deleted-user-x7XmeRtVHyGE · ‎01-07-2016

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)

})

deleted-user-x7XmeRtVHyGE · ‎01-07-2016

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)

})

RobertScheitlin__GISP · ‎01-07-2016

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.

deleted-user-x7XmeRtVHyGE · ‎01-07-2016

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!

RobertScheitlin__GISP · ‎01-07-2016

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.