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Query layer and return only the graphics selected

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06-27-2014 08:34 AM
AlexGole1
Emerging Contributor
Hi all,

I am trying to create an application that allows users to query a layer and return only the graphics based on their selection, not only highlight the selected graphics.

Form instance, In my case, I want to query by users. As shown below I have a blue hashed polygon that represents Calmap users, in red I have "unknown users". My goal here is therefore to create a simple query that only returns the blue hashed polygon or red hashed polygon.


I have used this example but first it returns an error and also it will not return the exact same symbology as the feature layer I am using (is there a way to do that?).

  var gp, map, toc, dynaLayer1, query, queryTask;    var geocoder;       var symbol, infoTemplate, extractMethod;       var AOI, graphic, clipFeatureSet, clipFeature;       require(["dojo/_base/connect",          "dojo/dom", "dojo/dom-style", "dojo/parser", "dojo/on", "dojo/_base/Color",          "esri/map", "esri/config",          "esri/dijit/HomeButton",          "esri/dijit/BasemapGallery",          "esri/dijit/Bookmarks",          "esri/dijit/Scalebar",          "esri/geometry/Extent",          "esri/tasks/query", "esri/tasks/QueryTask",          "esri/layers/FeatureLayer",          "esri/layers/ArcGISTiledMapServiceLayer",          "esri/layers/ArcGISDynamicMapServiceLayer",          "esri/symbols/SimpleFillSymbol",          "esri/symbols/SimpleLineSymbol",          "esri/InfoTemplate",    "esri/tasks/FeatureSet",    "esri/graphic",          "agsjs/dijit/TOC",          "dijit/registry",          "dijit/layout/BorderContainer",          "dijit/layout/ContentPane",          "dijit/layout/AccordionContainer",          "dijit/TitlePane",          "dijit/form/CheckBox",          "dijit/form/ComboBox",          "dojo/parser",          "dijit/Toolbar",          "dijit/form/DropDownButton",    "dijit/layout/TabContainer",          "dijit/form/TextBox",          "dijit/TooltipDialog",          "dijit/ToolbarSeparator",          "dojo/domReady!"       ], function (connect, dom, domStyle, parser, on, Color,          Map, esriConfig, HomeButton, BasemapGallery, Bookmarks, Scalebar, Extent, Query, QueryTask, FeatureLayer, ArcGISTiledMapServiceLayer, ArcGISDynamicMapServiceLayer,          SimpleFillSymbol, SimpleLineSymbol, InfoTemplate, FeatureSet, Graphic,          TOC, registry) {           // call the parser to create the dijit layout dijits          parser.parse(); // note djConfig.parseOnLoad = false;           // Specify where the location of the proxy to use to communicate with the extract GP service.          esriConfig.defaults.io.proxyUrl = "/proxy";            // Keep a reference to the loading icon DOM node.          var loading = dom.byId("loading");                     map = new Map("map", {             logo: true,             sliderPosition: "top-right",             basemap: "topo",             center: [-121.469, 38.556],             zoom: 8          });           var home = new HomeButton({             map: map          }, "HomeButton");          home.startup();           var basemapGallery = new BasemapGallery({             showArcGISBasemaps: true,             map: map          }, "basemapGallery");          basemapGallery.startup();                  var bookmarks = new Bookmarks({             map: map,             bookmarks: [],             editable: true          }, dom.byId('bookmarks'));           var scalebar = new Scalebar({             map: map,             // "dual" displays both miles and kilmometers             // "english" is the default, which displays miles             // use "metric" for kilometers             scalebarUnit: "dual",             scalebarStyle: "ruler",             attachTo: "bottom-left"          });           dynaLayer1 = new ArcGISDynamicMapServiceLayer("http://webgisdevint1/arcgis/rest/services/Alex_Try/Archived/MapServer", {});           map.on('layers-add-result', function (evt) {             dynaLayer1.setVisibleLayers([1, 2, 4]);             toc = new TOC({                map: map,                layerInfos: [{                   layer: dynaLayer1,                   title: "Layers",                   slider: true                }]             }, 'tocdiv');             toc.startup();          });          map.addLayers([dynaLayer1]);            symbol = new SimpleFillSymbol(SimpleFillSymbol.STYLE_SOLID,             new SimpleLineSymbol(SimpleLineSymbol.STYLE_SOLID, new Color([111, 0, 255]), 2), new Color([255, 255, 0, 0.25]));          infoTemplate = new InfoTemplate("${OBJECTID}", "${*}");           registry.byId("query").on("click", executeQuery);           function executeQuery(name) {                 var name = document.getElementById("user").value       var queryTask = new QueryTask("http://webgisdevint1/arcgis/rest/services/Alex_Try/Archived/MapServer/0");             queryTask.on("complete", showResults)    var query = new Query();             query.returnGeometry = true;             query.outFields = ["LAST_EDITED_USER"];             query.where = "LAST_EDITED_USER = '" + name + "'";             query.outSpatialReference = map.spatialReference;             queryTask.execute(query, showResults);    }           function showResults(featureSet) {          //remove all graphics on the maps graphics layer          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);         }        }


The error I get is:


"Cannot read property 'length' of undefined"



Thank you,
Alex

[ATTACH=CONFIG]34956[/ATTACH]
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1 Solution

Accepted Solutions
TracySchloss
Honored Contributor
If you're going to remove the queryTask.on ('complete', handlerFunction),  and stick with queryTask.execute(query, handlerFunction) then you want to leave your showResults function as

function showResults(featureSet){ var features = featureSet.features; 


If you want to want to go with
queryTask.execute(query, handlerFunction);


That's where you'd have your results function as

function showResults (results) { var features = results. featureSet.features;


I also think your for statement looks a little weird.  Maybe it should be
for (var i=0; i<features.length; i++){

View solution in original post

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20 Replies
MichaelVolz
Esteemed Contributor
Do you have a public sample of this website that can be run?

Can you check that name is getting populated correctly as I assume it is from some type of user input?
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AlexGole1
Emerging Contributor
Do you have a public sample of this website that can be run?

Can you check that name is getting populated correctly as I assume it is from some type of user input?


Let me make it public.
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AlexGole1
Emerging Contributor
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MichaelVolz
Esteemed Contributor
Can you make your mapservice(s) public as well as I cannot get to the Rest endpoint?
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AlexGole1
Emerging Contributor
Sorry, give it a shot now.
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MichaelVolz
Esteemed Contributor
Did you ever try running the sample with ESRI's data?  Did the sample work with their data?

I'm not really sure why featureSet.features is undefined as I see features populated in the console of Firebug.

I will try to modify ESRI's sample to use my data to see if I can get it to work (as I can use it for my applications), which might help determine why this variable is undefined and giving you the error.
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AlexGole1
Emerging Contributor
Did you ever try running the sample with ESRI's data?  Did the sample work with their data?

I'm not really sure why featureSet.features is undefined as I see features populated in the console of Firebug.

I will try to modify ESRI's sample to use my data to see if I can get it to work (as I can use it for my applications), which might help determine why this variable is undefined and giving you the error.


No I have not. I am only using a portion of the ESRI  code found here:

https://developers.arcgis.com/javascript/jshelp/intro_querytask.html


I dont understand why this returns an "undefinded" error message error either.


Let me know if it works for you.


I know I should proceed one step at a time but , if  ever, you have any idea how to keep the original symbology of the feature layer after the query is returned, that would be great.

Thank you,
Alex
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YungKaiChin
Regular Contributor
Have you tried nest the function within?
Ex:
queryTask.execute(query, function(featureSet) { alert(featureSet.length);});


See if you get anything.
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AlexGole1
Emerging Contributor
Have you tried nest the function within?
Ex:
queryTask.execute(query, function(featureSet) { alert(featureSet.length);});


See if you get anything.


Ok I am trying your idea right now:
function executeQuery(name) {
            
   var name = document.getElementById("user").value   
   var queryTask = new QueryTask("http://webgisdevint1/arcgis/rest/services/Alex_Try/Archived/MapServer/0");
            queryTask.on("complete", showResults)
   var query = new Query();
            query.returnGeometry = true;
            query.outFields = ["LAST_EDITED_USER"];
            query.where = "LAST_EDITED_USER = '" + name + "'";
            query.outSpatialReference = map.spatialReference;
            queryTask.execute(query, showResults(featureSet) { alert(featureSet.length);});
   }

         function showResults(featureSet) {
         //remove all graphics on the maps graphics layer
         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 a common error of:

Uncaught SyntaxError: Unexpected token { 


what am I doing wrong here?
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