Two query tasks

ToddFagin — Thu, 09 May 2019 19:37:01 GMT

Brief overview: I am wanting to show both georeferenced species occurrences and county-level species occurrences because not all of our records are georeferenced. For this purpose, I have two feature layers, a 5km²hexagonal grid for the georeferenced locations and a county layer. Both have a column called sname for the species name.

I have created a query task for both based on the same query. However, I cannot seem to get both of the results to show simultaneously. I have tried reordering, addMany for the graphics, and a bunch of other stuff, but nothing seems to work right.

Any suggestions would be greatly appreciated.

Code snippet:

      // Define sql expression eventually want to bind to record selected in OBIS explorer
      var query = new Query();
      query.where = "sname = 'Nicrophorus americanus'"
      query.outFields = ["*"];
      query.returnGeometry = true;

      // Define the query task for hexagons
      var hexquery = new QueryTask({
        url: "https://obsgis.csa.ou.edu:6443/arcgis/rest/services/ONHI/OBIS_5km_Occurrences/MapServer/0/"
      });

      // Define the query task for county polygons
      var coquery = new QueryTask({
        url: "https://obsgis.csa.ou.edu:6443/arcgis/rest/services/ONHI/OBIS_County_Occurrences_Poly/MapServer/0/"
      });

      // Execute the Hexagon Query
      hexquery.execute(query)
        .then(function(result){
          result.features.forEach(function(item){
             var hexgraphic = new Graphic({
               geometry: item.geometry,
               attributes: item.attributes,
               symbol: {
                 type: "simple-fill",
                 color: [115, 178, 115],
                 style: "solid",
                 outline: null
               },
               popupTemplate: {
                 title: "<em>{sname}</em> ({vernacularname})",
                 content: "ONHI has {count} occurrence record(s) for <em>{sname}</em> ({vernacularname}) in this hexagon"
               }
             });

             view.graphics.add(hexgraphic);
          });
         })


      // Execute the County Query
      coquery.execute(query)
        .then(function(result){
          result.features.forEach(function(item){
             var cographic = new Graphic({
               geometry: item.geometry,
               attributes: item.attributes,
               symbol: {
                 type: "simple-fill",
                 color: [240, 253, 230],
                 style: "solid",
                 outline: { // autocasts as new SimpleLineSymbol()
                    color: "black",
                    width: 0.5
                  }
               },
               popupTemplate: {
                 title: "<em>{sname}</em> ({vernacularname})",
                 content: "ONHI has {count} occurrence record(s) for <em>{sname}</em> ({vernacularname}) in {county} County"
               }
             });

             view.graphics.add(cographic);
          });

         })
        .otherwise(function(e){
          console.log(e);
        });

Full code:

<html>
<head>
<meta name="description" content="DevLav: Query a feature layer">
<meta charset="utf-8">
<meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no">
<title>County Level Species Occurrences</title>
<style>
    html,
    body,
    #viewDiv {
      padding: 0;
      margin: 0;
      height: 100%;
      width: 100%;
    }
    .esri-view:fullscreen {
      background-color: #fff;
    }
</style>
<link rel="stylesheet" href="https://js.arcgis.com/4.11/esri/css/main.css">
<script src="https://js.arcgis.com/4.11/"></script>
</head>

<script>
require([
      "esri/Map",
      "esri/views/MapView",
      "esri/layers/FeatureLayer",
      "esri/renderers/SimpleRenderer",
      "esri/geometry/Extent",
      "esri/geometry/SpatialReference",
      "esri/tasks/support/Query",
      "esri/tasks/QueryTask",
      "esri/Graphic",
      "esri/widgets/Fullscreen"
    ],
    function(
      Map,
      MapView,
      FeatureLayer,
      SimpleRenderer,
      Extent,
      SpatialReference,
      Query,
      QueryTask,
      Graphic,
      Fullscreen
    ) {

      //map extent: Need this since no basemap; otherwise extent is pretty wonky
      var bounds = new Extent({
            "xmin":-103.5,
            "ymin":33.0,
            "xmax":-93.5,
            "ymax":37.5,
            "spatialReference":{"wkid":4326} //this is for the extent only; need to set map spatial reference in view.
        });



      // Oklahoma Counties Layer
        var okcounties = new FeatureLayer({
             url: "https://obsgis.csa.ou.edu:6443/arcgis/rest/services/ONHI/ArcGISServer_Counties/MapServer"


       });


      var map = new Map({
        //basemap: "satellite",
        layers: [okcounties]
      });


      var view = new MapView({
        container: "viewDiv",
        map: map,
        extent: bounds,
        spatialReference: 3857 //spatial reference of map; different from the extent
      });


      // Define sql expression eventually want to bind to record selected in OBIS explorer
      var query = new Query();
      query.where = "sname = 'Nicrophorus americanus'"
      query.outFields = ["*"];
      query.returnGeometry = true;

      // Define the query task for hexagons
      var hexquery = new QueryTask({
        url: "https://obsgis.csa.ou.edu:6443/arcgis/rest/services/ONHI/OBIS_5km_Occurrences/MapServer/0/"
      });

      // Define the query task for county polygons
      var coquery = new QueryTask({
        url: "https://obsgis.csa.ou.edu:6443/arcgis/rest/services/ONHI/OBIS_County_Occurrences_Poly/MapServer/0/"
      });

      // Execute the Hexagon Query
      hexquery.execute(query)
        .then(function(result){
          result.features.forEach(function(item){
             var hexgraphic = new Graphic({
               geometry: item.geometry,
               attributes: item.attributes,
               symbol: {
                 type: "simple-fill",
                 color: [115, 178, 115],
                 style: "solid",
                 outline: null
               },
               popupTemplate: {
                 title: "<em>{sname}</em> ({vernacularname})",
                 content: "ONHI has {count} occurrence record(s) for <em>{sname}</em> ({vernacularname}) in this hexagon"
               }
             });

             view.graphics.add(hexgraphic);
          });
         })


      // Execute the County Query
      coquery.execute(query)
        .then(function(result){
          result.features.forEach(function(item){
             var cographic = new Graphic({
               geometry: item.geometry,
               attributes: item.attributes,
               symbol: {
                 type: "simple-fill",
                 color: [240, 253, 230],
                 style: "solid",
                 outline: { // autocasts as new SimpleLineSymbol()
                    color: "black",
                    width: 0.5
                  }
               },
               popupTemplate: {
                 title: "<em>{sname}</em> ({vernacularname})",
                 content: "ONHI has {count} occurrence record(s) for <em>{sname}</em> ({vernacularname}) in {county} County"
               }
             });

             view.graphics.add(cographic);
          });

         })
        .otherwise(function(e){
          console.log(e);
        });




        fullscreen = new Fullscreen({
          view: view
       });
       view.ui.add(fullscreen, "top-right");


       view.when(disableZooming);

        /**
         * Disables all zoom gestures on the given view instance.
         *
         * @param {esri/views/MapView} view - The MapView instance on which to
         *                                  disable zooming gestures.
         */
        function disableZooming(view) {
          view.popup.dockEnabled = true;

          // Removes the zoom action on the popup
          view.popup.actions = [];

          // stops propagation of default behavior when an event fires
          function stopEvtPropagation(event) {
            event.stopPropagation();
          }

          // exlude the zoom widget from the default UI
          view.ui.components = ["attribution"];

          // disable mouse wheel scroll zooming on the view
          view.on("mouse-wheel", stopEvtPropagation);

          // disable zooming via double-click on the view
          view.on("double-click", stopEvtPropagation);

          // disable zooming out via double-click + Control on the view
          view.on("double-click", ["Control"], stopEvtPropagation);

          // disables pinch-zoom and panning on the view
          view.on("drag", stopEvtPropagation);

          // disable the view's zoom box to prevent the Shift + drag
          // and Shift + Control + drag zoom gestures.
          view.on("drag", ["Shift"], stopEvtPropagation);
          view.on("drag", ["Shift", "Control"], stopEvtPropagation);

          // prevents zooming with the + and - keys
          view.on("key-down", function(event) {
            var prohibitedKeys = ["+", "-", "Shift", "_", "="];
            var keyPressed = event.key;
            if (prohibitedKeys.indexOf(keyPressed) !== -1) {
              event.stopPropagation();
            }
          });

          return view;
        }


    });

</script>
</head>

<body>
<div id="viewDiv"></div>
</body>

</html>

Re: Two query tasks

RobertScheitlin__GISP — Thu, 09 May 2019 19:45:37 GMT

Todd,

Consider using dojo/promise/all. It will await all the promises to return (i.e. both of the queryTasks) before returning an array of the results from each.

Re: Two query tasks

ToddFagin — Thu, 09 May 2019 21:01:08 GMT

As always, thank you for your prompt, insightful reply, Robert. I will look into this.

In the meantime, I realized I may be over-complicating this. I am pursuing using a simple definitionExpression with each of the FeatureLayers rather than using a query task. It seems to do what I want/need, so this may be the route I take.

Thanks again.

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