topic Re: Feature Layer and a Graphics Layer?!? in ArcGIS JavaScript Maps SDK Questions

Feature Layer and a Graphics Layer?!?

AaronWeier — Wed, 17 Oct 2012 13:23:51 GMT

Hi All,

I am running into a very confusing issue. I have a map service with about 45 layers and 5 tables. I am creating feature layers based on a drop down chosen by the user. Then, after the feature layer is displayed on screen, the user can select a feature on the map and see attribute data in a dashboard-like div.

Problem is: I cannot seem to remove layers from the map, they just keep piling up. I know this by using the map.graphicLayersIds.length function and logging the id.

so my question is, am i piling up graphicslayers and featurelayers? Are they one and the same? Am I trying to remove the wrong thing?

I've seen some other issues posted regarding map.removeLayer but none of those solutions has helped me.

Appreciate any feedback!
Aaron

Re: Feature Layer and a Graphics Layer?!?

__Rich_ — Wed, 17 Oct 2012 13:29:03 GMT

A FeatureLayer is a specialised GraphicsLayer - see the inheritance tree (or mixin hierarchy in Dojo terms).

But map.removeLayer() is type-agnostic i.e. you don't need to differentiate between Graphics and non-Graphics layers, that's taken care of in the API.

How are you calling removeLayer()? You are passing it a reference to the layer you want to remove, aren't you?

Re: Feature Layer and a Graphics Layer?!?

AaronWeier — Sat, 11 Dec 2021 08:05:18 GMT

thanks for the quick reply.

FYI: i'm using map and hvaFeatureLayer as global vars; ArcGIS Server v10; jsapi v3.2.

here's the basics:

init calls a function to create the featurelayer:

function createFL(layerid) {

            hvaFeatureLayer = new esri.layers.FeatureLayer("<mapserver url>/" + layerid, {
                mode: esri.layers.FeatureLayer.MODE_ONDEMAND,
                outFields: ["*"]
            });
            hvaFeatureLayer.setRenderer(getRenderer("Stoplight")); //custom green, yellow, red indicators

            AddLayersToMap();

        }

createFL calls AddLayersToMap:

function AddLayersToMap() {

//if current graphics layer exists, call graphics layer function to get layer and remove it
            if (map.graphicsLayerIds.length >= 1) {
                getMapGraphicsLayers();
            }
           
            map.addLayer(hvaFeatureLayer);

            dojo.connect(hvaFeatureLayer, "onUpdateStart", function () {
                hvaFeatureLayer.id = hvaFeatureLayer.name;
            });


            //event listener for when user clicks on map
            dojo.connect(map, "onClick", executeSelectQueryTask);

            dojo.connect(hvaFeatureLayer, "onMouseOver", function (evt) {
                var t = "${LPHA_TRIBE_NAME}";
                var content = esri.substitute(evt.graphic.attributes, t);

                dialog.setContent(content);

                dojo.style(dialog.domNode, "opacity", 1);
                dijit.popup.open({ popup: dialog, x: evt.pageX, y: evt.pageY });

            });

            //close the dialog when the mouse leaves the highlight graphic
            dojo.connect(map, "onLoad", function () {
                map.graphics.enableMouseEvents();
                dojo.connect(map.graphics, "onMouseOut", closeDialog);
            });
  
        }

This function tests for graphics layers and calls function below to get the GL and remove it.

function getMapGraphicsLayers() {
            console.log(">>>>>>>>>>>>>>>  GL count: " + map.graphicsLayerIds.length);
            for (var j = 0, jl = map.graphicsLayerIds.length; j < jl; j++) {
                var currentGraphicsLayer = map.getLayer(map.graphicsLayerIds);
                //console.log("Graphics Layer ID: " + currentGraphicsLayer.id);
                map.removeLayer(currentGraphicsLayer);
            }
        }

After the map loads, the user is presented with a drop down list of layers to choose. After choosing a new layer, createFL gets called with the selected layer id and the process of adding a new feature layer and testing for graphics layer continues:

function changeHaz(value) {

            //if (hvaFeatureLayer){
            //     map.removeLayer(hvaFeatureLayer);
            //}
            
            //alert(value.substring(0,value.length-1));
            layerid = getIdFromMapService($.trim(value));
            createFL(layerid);

        }

i tried the 'map.removeLayer(hvaFeatureLayer);' call here but it doesn't work so i tried the graphics approach.

This is where I felt my lack of understanding between FL and GL came into play. And, obviously, i'm still not quite grasping something here....

Thanks again for any help you can provide!
Aaron

Re: Feature Layer and a Graphics Layer?!?

__Rich_ — Thu, 18 Oct 2012 07:58:15 GMT

I've modified (hacked!) this sample and added 2 buttons, both remove the FeatureLayer, the top button uses the global reference to the layer the second button uses your loop code to gain a reference to the layer, both work fine.

Without seeing the whole site, it's hard to know specifically what's not working for you, maybe someone else can spot a syntax error etc.

Are you using any development tools e.g. Firebug to help you debug?

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html>      <head>     <title>Dynamic Layer</title>     <meta http-equiv="Content-Type" content="text/html; charset=utf-8">     <meta http-equiv="X-UA-Compatible" content="IE=7,IE=9" />     <link rel="stylesheet" type="text/css" href="http://serverapi.arcgisonline.com/jsapi/arcgis/3.2/js/dojo/dijit/themes/claro/claro.css">     <link rel="stylesheet" type="text/css" href="http://serverapi.arcgisonline.com/jsapi/arcgis/3.2/js/esri/css/esri.css" />      <script type="text/javascript">dojoConfig = { parseOnLoad: true };</script>      <script type="text/javascript" src="http://serverapi.arcgisonline.com/jsapi/arcgis/?v=3.2"></script>     <style>     html, body, #mapDiv, .map.container {       padding:0;       margin:0;       height:100%;     }     </style>     <script type="text/javascript">         dojo.require("esri.map");         dojo.require("esri.layers.FeatureLayer");         var map, featureLayer;          function init() {              esri.config.defaults.geometryService = new esri.tasks.GeometryService("http://tasks.arcgisonline.com/ArcGIS/rest/services/Geometry/GeometryServer");              var initialExtent = new esri.geometry.Extent({                 "xmin": -167.3,                 "ymin": -69.59,                 "xmax": 160.32,                 "ymax": 71.91,                 "spatialReference": {                     "wkid": 4326                 }             });             map = new esri.Map("mapDiv", {                 wrapAround180: true,                 extent: esri.geometry.geographicToWebMercator(initialExtent)             });              dojo.connect(map, 'onLoad', initOperationalLayer);              //Add the World Imagery service as a basemap to the map             var basemap = new esri.layers.ArcGISTiledMapServiceLayer("http://server.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer");             map.addLayer(basemap);           }          function initOperationalLayer(map) {              var content = "<b>Name</b>: ${NAME}" + "<br /><b>Area</b>: ${ss6.gdb.Lakes.AREA:NumberFormat(places:0)}";             var infoTemplate = new esri.InfoTemplate("Dynamic Layer", content);              //define the layer's data source from a table             var dataSource = new esri.layers.TableDataSource();             dataSource.workspaceId = "MyDatabaseWorkspaceIDSSR2";             dataSource.dataSourceName = "ss6.gdb.Lakes";             var layerSource = new esri.layers.LayerDataSource();             layerSource.dataSource = dataSource;              //create a new feature layer based on the table data source              featureLayer = new esri.layers.FeatureLayer('http://sampleserver6.arcgisonline.com/arcgis/rest/services/USA/MapServer/dynamicLayer', {                 mode: esri.layers.FeatureLayer.MODE_ONDEMAND,                 outFields: ["*"],                 infoTemplate: infoTemplate,                 source: layerSource             });             dojo.connect(featureLayer, "onLoad", function (layer) {                 //project the extent if the map's spatial reference is different that the layer's extent.                 var gs = esri.config.defaults.geometryService;                 var extent = layer.fullExtent;                 if (extent.spatialReference.wkid === map.spatialReference.wkid) {                     map.setExtent(extent);                 } else {                     gs.project([extent], map.spatialReference).then(function (results) {                         map.setExtent(results[0]);                     });                 }             });              var renderer = new esri.renderer.SimpleRenderer(               new esri.symbol.SimpleFillSymbol("solid", null, new dojo.Color([255, 0, 255, 0.75]) // fuschia lakes!             ));              featureLayer.setRenderer(renderer);             map.addLayer(featureLayer);             map.infoWindow.resize(150, 105);               dojo.connect(window, 'resize', map, map.resize);         }         dojo.addOnLoad(init);          function removeFeatureLayer() {             map.removeLayer(featureLayer);         }         function removeFeatureLayer2() {             console.log(">>>>>>>>>>>>>>>  GL count: " + map.graphicsLayerIds.length);             for (var j = 0, jl = map.graphicsLayerIds.length; j < jl; j++) {                 var currentGraphicsLayer = map.getLayer(map.graphicsLayerIds);                 //console.log("Graphics Layer ID: " + currentGraphicsLayer.id);                 map.removeLayer(currentGraphicsLayer);             }         }     </script>   </head>      <body class='claro'>     <div id="mapDiv"></div>       <input type="button" value="Remove Feature Layer" style="position:absolute;bottom:40px;left:10px;" onclick="removeFeatureLayer()" />       <input type="button" value="Remove Feature Layer 2" style="position:absolute;bottom:10px;left:10px;" onclick="removeFeatureLayer2()" />   </body>  </html>

edit: Hang on...just a thought the removeLayer method uses the layer reference passed in to detect the layer to remove...but I think you may have indirectly changed the referenced layer when you assigned the new layer to the hvaFeatureLayer variable, thus it cannot find a layer in it's list of existing layers that match that reference...so your layer list keeps growing.

Haven't had time to think this through fully though...

Re: Feature Layer and a Graphics Layer?!?

__Rich_ — Sat, 11 Dec 2021 08:05:20 GMT

Haven't had time to think this through fully though...

think I may be right, check out this modified code, I think it replicates your issue:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
  
  <head>
    <title>Dynamic Layer</title>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=7,IE=9" />
    <link rel="stylesheet" type="text/css" href="http://serverapi.arcgisonline.com/jsapi/arcgis/3.2/js/dojo/dijit/themes/claro/claro.css">
    <link rel="stylesheet" type="text/css" href="http://serverapi.arcgisonline.com/jsapi/arcgis/3.2/js/esri/css/esri.css" />

    <script type="text/javascript">dojoConfig = { parseOnLoad: true };</script>

    <script type="text/javascript" src="http://serverapi.arcgisonline.com/jsapi/arcgis/?v=3.2"></script>
    <style>
    html, body, #mapDiv, .map.container {
      padding:0;
      margin:0;
      height:100%;
    }
    </style>
    <script type="text/javascript">
        dojo.require("esri.map");
        dojo.require("esri.layers.FeatureLayer");
        var map, featureLayer;

        function init() {

            esri.config.defaults.geometryService = new esri.tasks.GeometryService("http://tasks.arcgisonline.com/ArcGIS/rest/services/Geometry/GeometryServer");

            var initialExtent = new esri.geometry.Extent({
                "xmin": -167.3,
                "ymin": -69.59,
                "xmax": 160.32,
                "ymax": 71.91,
                "spatialReference": {
                    "wkid": 4326
                }
            });
            map = new esri.Map("mapDiv", {
                wrapAround180: true,
                extent: esri.geometry.geographicToWebMercator(initialExtent)
            });

            dojo.connect(map, 'onLoad', initOperationalLayer);

            //Add the World Imagery service as a basemap to the map
            var basemap = new esri.layers.ArcGISTiledMapServiceLayer("http://server.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer");
            map.addLayer(basemap);


        }

        function initOperationalLayer() {

            var content = "<b>Name</b>: ${NAME}" + "<br /><b>Area</b>: ${ss6.gdb.Lakes.AREA:NumberFormat(places:0)}";
            var infoTemplate = new esri.InfoTemplate("Dynamic Layer", content);

            //define the layer's data source from a table
            var dataSource = new esri.layers.TableDataSource();
            dataSource.workspaceId = "MyDatabaseWorkspaceIDSSR2";
            dataSource.dataSourceName = "ss6.gdb.Lakes";
            var layerSource = new esri.layers.LayerDataSource();
            layerSource.dataSource = dataSource;

            //create a new feature layer based on the table data source 
            featureLayer = new esri.layers.FeatureLayer('http://sampleserver6.arcgisonline.com/arcgis/rest/services/USA/MapServer/dynamicLayer', {
                mode: esri.layers.FeatureLayer.MODE_ONDEMAND,
                outFields: ["*"],
                infoTemplate: infoTemplate,
                source: layerSource
            });
            dojo.connect(featureLayer, "onLoad", function (layer) {
                //project the extent if the map's spatial reference is different that the layer's extent.
                var gs = esri.config.defaults.geometryService;
                var extent = layer.fullExtent;
                if (extent.spatialReference.wkid === map.spatialReference.wkid) {
                    map.setExtent(extent);
                } else {
                    gs.project([extent], map.spatialReference).then(function (results) {
                        map.setExtent(results[0]);
                    });
                }
            });

            var renderer = new esri.renderer.SimpleRenderer(
              new esri.symbol.SimpleFillSymbol("solid", null, new dojo.Color([255, 0, 255, 0.75]) // fuschia lakes!
            ));

            featureLayer.setRenderer(renderer);
            map.addLayer(featureLayer);
            map.infoWindow.resize(150, 105);


            dojo.connect(window, 'resize', map, map.resize);
        }
        dojo.addOnLoad(init);

        function removeFeatureLayer() {
            initOperationalLayer();  //Simulates the new layer call in your code
            map.removeLayer(featureLayer);
        }
        function removeFeatureLayer2() {
            initOperationalLayer(); //Simulates the new layer call in your code
            console.log(">>>>>>>>>>>>>>>  GL count: " + map.graphicsLayerIds.length);
            for (var j = 0, jl = map.graphicsLayerIds.length; j < jl; j++) {
                var currentGraphicsLayer = map.getLayer(map.graphicsLayerIds);
                //console.log("Graphics Layer ID: " + currentGraphicsLayer.id);
                map.removeLayer(currentGraphicsLayer);
            }
        }
    </script>
  </head>
  
  <body class='claro'>
    <div id="mapDiv"></div>
      <input type="button" value="Remove Feature Layer" style="position:absolute;bottom:40px;left:10px;" onclick="removeFeatureLayer()" />
      <input type="button" value="Remove Feature Layer 2" style="position:absolute;bottom:10px;left:10px;" onclick="removeFeatureLayer2()" />
  </body>

</html>

Re: Feature Layer and a Graphics Layer?!?

AaronWeier — Sat, 11 Dec 2021 08:05:23 GMT

Geos -

I really appreciate all the effort in helping me with this issue. I've been using IE Dev Tools since the site i'm working on will be a site page in SharePoint. All other code works with no errors, so i've only provided the necessary bits that handle the add and remove layer.

I think I've found the problem based on this statement

I think you may have indirectly changed the referenced layer

I did change the reference layer, right after 'onLoad', with this code (that i've now commented out).

//            dojo.connect(hvaFeatureLayer, "onUpdateStart", function () {
//                hvaFeatureLayer.id = hvaFeatureLayer.name;
//            });

Thanks again for all your assistance!

Aaron