topic Query and QueryTask in Web AppBuilder Custom Widgets Questions

Query and QueryTask

MargaRaiz — Mon, 19 Sep 2016 11:39:06 GMT

Hello,

I have been trying to query a layer and show the results in the map but I can't make it work, this is my try:

define([ 'jimu/BaseWidget', 'dojo/_base/connect', 'dojo/_base/declare', 'dojo/_base/lang', 'dojo/_base/array', 'dojo/_base/html', 'dojo/dom', 'dojo/on', 'dojo/query', 'esri/tasks/QueryTask', 'dijit/registry', 'esri/layers/FeatureLayer', 'esri/layers/Field','esri/request', 'dojo/store/Memory','jimu/LayerInfos/LayerInfos' ],

function (BaseWidget, connect, declare, lang, array, html, dom, on, Query, QueryTask, registry, FeatureLayer, field, esriRequest, Memory, LayerInfos) { return declare([BaseWidget], {
          baseClass: 'jimu-widget-mywidget',
          startup: function () {
              this.inherited(arguments);
              console.log('startup');
              var map = this.map;
              queryTask = new QueryTask("http://10.81.6.16:6080/arcgis/rest/services/MyLayer/FeatureServer/0");
              query = new Query();
              query.returnGeometry = true;
              query.outFields = ["OBJECTID"];

              if (map.loaded) {
                  query.where = "OBJECTID = 1";
                  queryTask.execute(query, showResults);
              } else {
                  map.on("load", function () {
                      query.where = "OBJECTID = 1";
                      queryTask.execute(query, showResults);
                  });
              }

               function showResults(featureSet) {
                    map.graphics.clear();

//Performance enhancer - assign featureSet array to a single variable.
var resultFeatures = featureSet.features;

                   //Loop through each feature returned
                   for (var i=0, il=resultFeatures.length; i<il; i++) {
                   //Get the current feature from the featureSet.
                   //Feature is a graphic
                   var graphic = resultFeatures;
                   graphic.setSymbol(symbol);

//Set the infoTemplate.
graphic.setInfoTemplate(infoTemplate);

                   //Add graphic to the map graphics layer.
                   map.graphics.add(graphic);
               }
               }

(......)

I get this mistake:

TypeError: a.toJson is not a function

...nction(){},onExecuteRelationshipQueryComplete:function(){},onExecuteForIdsComple...

Can any one tell me if I am using query and querytask in the correct way? I have been following other threats of this forum to write this piece of code.

Thanks!

Marga

Re: Query and QueryTask

RobertScheitlin__GISP — Mon, 19 Sep 2016 11:50:37 GMT

Marga,

The first thing I see wrong in your code is that you are using a 'dojo/query' instead of 'esri/tasks/Query'. If you swap that require you should try your code again.

Re: Query and QueryTask

MargaRaiz — Mon, 19 Sep 2016 12:18:31 GMT

Hi Robert,

Thanks!

I have modified my code and now I don't get that error and works fine!

Is it neccesary to write code for showing the results in the map, I mean, in this case is it neccesary the showResults function? Because is the only way that I have found to do that, but.. maybe are there other ways?

Marga

Re: Query and QueryTask

MargaRaiz — Tue, 20 Sep 2016 11:57:33 GMT

Hello,

I am also wondering if is it possible to show de results (the featureset get from applying the querytask) in the attribute table widget.

I have read in the documentation of esri this: "Send a layer to the Attribute Table widget: The following steps demonstrate how to send a layer from your widget to the Attribute Table widget. Since the attribute table only displays layers in the map, make sure to add the layer to the map." (Send a layer to the Attribute Table widget—Web AppBuilder for ArcGIS (Developer Edition) | ArcGIS for Developers ). But the only thing that I get from runing the querytask is a featureset.

And I have done some research in the wab community, I have found this thread related to this:

https://community.esri.com/message/616240?commentID=616240#comment-621609

In which is mentioned how to apply a filter to the attribute table, so I definitely want to have my query results in the attribute table, so maybe I have better to follow that idea instead of trying with the query and querytask right?

Marga

Re: Query and QueryTask

RobertScheitlin__GISP — Tue, 20 Sep 2016 12:44:35 GMT

Marga,

If you want to add the query results to the map then you have to take the results and create a FeatureLayer from the results and add that to the map.

FeatureLayer | FeatureCollection | API Reference | ArcGIS API for JavaScript 3.17

Or as you said it may be easier to just filter the data in the attribute table.

Re: Query and QueryTask

MargaRaiz — Thu, 22 Sep 2016 12:48:50 GMT

Hello!

I finally decided to create a featureclass because I will need to use 'esri/tasks/Query' to make some spatial queries and as far as I know I can't filter from the AT widget with spatial criteria. So I have create my featureclass from the featureset with no problem and add to the map to see in a graphic way the layer (this is working fine):

                      //Create the layer when the querytask is launched
                      var layerDefinition = {
                          "geometryType": featureSet.geometryType,
                          "fields": featureSet.fields
                      }
                      var featureCollection = {
                          layerDefinition: layerDefinition,
                          featureSet: featureSet
                      };
                      layerResult = new FeatureLayer(featureCollection, {
                          showLabels: true
                      });

layerResult .name = 'L_Result';
map.addLayer(layerResult );

The query criterias are selected from a window, and can be launched as much as the user wants, so I realize that I need to remove the layerResult from the map before adding the new one with the new query criteria (otherwise I finished with a lot of layers added to the map). I do that with this piece of code:

                      // Remove layerResult before creating a new one
                      if (typeof (layerResult ) !== 'undefined') {
                          map.removeLayer(layerResult);
                      }

Maybe I am nor removing this layer in a proper way because this layer its removed from the map BUT when I openned the attribute table after launching for example 3 queries, there are 3 LayerResul (one from each result) so its clear that it hasn't been removed from the attribute table.. Any ideas about why is this layer still in the attribute tables?

I have been doing some research with layerTabPageClose method (AttributeTable/Widget.js) but with no succeed. I have also thought about destroying this widget and reload it but I think that this is not a suitable solution.

Any ideas?

Marga

Re: Query and QueryTask

RobertScheitlin__GISP — Sun, 12 Dec 2021 10:19:53 GMT

Marga,

This is how I do it:

 if (this.tempResultLayer) {
    this.map.removeLayer(this.tempResultLayer);
 }
 this.tempResultLayer = null;‍‍‍‍