topic Re: Populate combobox with a layer from a map service. in ArcGIS API for Flex Questions

Populate combobox with a layer from a map service.

JasonLevine — Wed, 08 Dec 2010 16:00:52 GMT

I've been searching for the proper way of doing this, but I've only found how to populate a combobox with the results from a query. Basically, I'd like to create an ArrayCollection that contains all of the features of a single layer in a map service and use it as the data provider for my combobox. When a user clicks a feature in that layer in the combobox, the map will zoom to that feature.

I've put together the following code, but I'm definitely on the wrong track. Any help is appreciated.

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
      xmlns:s="library://ns.adobe.com/flex/spark"
      xmlns:esri="http://www.esri.com/2008/ags"
      pageTitle="Map Extent and Mouse Coordinates" 
      creationComplete="combobox()">
 
 <fx:Script>
  <![CDATA[
   
   import mx.collections.ArrayCollection;
  
   private function combobox():void
   {
    var comboArray:ArrayCollection = new ArrayCollection();
    comboArray = comm_layer.layerInfos.Communities_Places //the specific layer in the map service
    cmb.dataProvider = comboArray;
    cmb.labelField = comboArray.comm_name_ //field within the Communities_Places layer
   }
     
  ]]>
 </fx:Script>
 
 <s:layout>
  <s:VerticalLayout paddingTop="6"/>
 </s:layout>
 
 <s:HGroup>
  <s:ComboBox id="cmb" right="250"/>
 </s:HGroup>
 
 <esri:Map id="myMap">
  <esri:extent>
   <esri:Extent xmin="-13338986.2116637" ymin="3926661.77417242" xmax="-13002755.460699" ymax="4152028.76378653">
    <esri:SpatialReference wkid="3857"/>
   </esri:Extent>
  </esri:extent>
  <esri:ArcGISDynamicMapServiceLayer id="comm_layer" url="http://10.2.8.73/ArcGIS/rest/services/ZNET_Public/city_maskForExtent/MapServer"/>
 </esri:Map>

</s:Application>

Thanks,
Jason

Re: Populate combobox with a layer from a map service.

RobertScheitlin__GISP — Wed, 08 Dec 2010 16:44:18 GMT

Jason,

I think you are missing something here... The only way you can get the attributes and geometry for a specific layer IS to use a query. LayerInfo only has the layer name and it's id, definitely does not contain it's geometry of each individual feature.

Re: Populate combobox with a layer from a map service.

JasonLevine — Wed, 08 Dec 2010 17:06:35 GMT

Yah, I was definitely missing something here. I figured it out.

Thanks for pointing me in the right direction,
Jason

Re: Populate combobox with a layer from a map service.

DasaPaddock — Fri, 10 Dec 2021 22:30:02 GMT

Here's a sample too:

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
               xmlns:s="library://ns.adobe.com/flex/spark"
               xmlns:esri="http://www.esri.com/2008/ags">

    <fx:Script>
        <![CDATA[
            import com.esri.ags.Graphic;
            import com.esri.ags.events.MapEvent;
            import com.esri.ags.events.QueryEvent;
            import com.esri.ags.geometry.Extent;
            import com.esri.ags.tasks.supportClasses.Query;

            import mx.collections.ArrayList;

            import spark.events.IndexChangeEvent;

            protected function map_loadHandler(event:MapEvent):void
            {
                var query:Query = new Query();
                query.outFields = [ "STATE_NAME" ];
                query.outSpatialReference = map.spatialReference;
                query.returnGeometry = true;
                query.where = "1=1";
                queryTask.execute(query);
            }

            protected function queryTask_executeCompleteHandler(event:QueryEvent):void
            {
                ddList.dataProvider = new ArrayList(event.featureSet.features);
            }

            protected function ddListLabelFunction(item:Graphic):String
            {
                return item.attributes["STATE_NAME"];
            }

            protected function ddList_changeHandler(event:IndexChangeEvent):void
            {
                var stateExtent:Extent = Graphic(ddList.selectedItem).geometry.extent;
                map.extent = stateExtent

                // make sure the whole extent is visible
                if (!map.extent.contains(stateExtent))
                {
                    map.level--;
                }
            }
        ]]>
    </fx:Script>

    <fx:Declarations>
        <esri:QueryTask id="queryTask"
                        executeComplete="queryTask_executeCompleteHandler(event)"
                        showBusyCursor="true"
                        url="http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Demographics/ESRI_Census_USA/MapServer/5"
                        useAMF="false"/>
    </fx:Declarations>

    <s:controlBarContent>
        <s:DropDownList id="ddList"
                        width="200"
                        change="ddList_changeHandler(event)"
                        labelFunction="ddListLabelFunction"
                        prompt="Choose a state to zoom to"/>
    </s:controlBarContent>

    <esri:Map id="map" load="map_loadHandler(event)">
        <esri:ArcGISTiledMapServiceLayer url="http://server.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer"/>
    </esri:Map>

</s:Application>

Re: Populate combobox with a layer from a map service.

JasonLevine — Fri, 10 Dec 2021 22:30:05 GMT

Hi Dasa,
I'm using a comboBox instead of a dropdown list. I managed to populate it correctly, but I can't seem to get my change function figured out:

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
      xmlns:s="library://ns.adobe.com/flex/spark"
      xmlns:esri="http://www.esri.com/2008/ags"
      pageTitle="Map Extent and Mouse Coordinates" 
      creationComplete="combobox()">
 
 <fx:Script>
  <![CDATA[
   import com.esri.ags.FeatureSet;
   import com.esri.ags.Graphic;
   import com.esri.ags.events.QueryEvent;
   import com.esri.ags.tasks.QueryTask;
   import com.esri.ags.tasks.supportClasses.Query;
   import com.esri.ags.utils.GraphicUtil;
   
   import mx.collections.ArrayCollection;
  
   private function combobox():void
   {
   var comboQueryTask:QueryTask = new QueryTask();
   comboQueryTask.url = "http://10.2.8.73/ArcGIS/rest/services/ZNET_Public/city_mask/MapServer/0";
   comboQueryTask.useAMF = false;
   var comboQuery:Query = new Query();
   comboQuery.returnGeometry = true;
   comboQuery.where = "1=1";
   comboQuery.outFields = ["CITY_COMM_"];
   comboQuery.outSpatialReference = myMap.spatialReference;
   comboQueryTask.execute(comboQuery);
   comboQueryTask.addEventListener(QueryEvent.EXECUTE_COMPLETE, onQueryComplete);
   }
   
   private var commExtent:Extent = new Extent();
   private function onQueryComplete(event:QueryEvent):void
   {
    var featureSet:FeatureSet = event.featureSet;
    var results:ArrayCollection = new ArrayCollection();
    for each (var graphic:Graphic in featureSet.features)
    {
     var fieldValue:String = graphic.attributes["CITY_COMM_"].toString();
     results.addItem({label: fieldValue, data: graphic});
    }
    cmb.labelField = "label";
    cmb.dataProvider = results;
    var graphicsExtent:Extent = GraphicUtil.getGraphicsExtent(featureSet.features);
    commExtent = graphicsExtent;
    
   }
   
   private function change():void
   {
    var extent2:Extent = Graphic(cmb.selectedItem).geometry.extent;
    myMap.extent = extent2;
   }
   
     
  ]]>
 </fx:Script>
 
 <s:layout>
  <s:VerticalLayout paddingTop="6"/>
 </s:layout>
 
 <s:HGroup>
  <s:ComboBox id="cmb" right="250" change="change()" width="350" selectedItem="{{label:'Select Your Community'}}"/>
 </s:HGroup>
 
 <esri:Map id="myMap">
  <esri:extent>
   <esri:Extent xmin="-13338986.2116637" ymin="3926661.77417242" xmax="-13002755.460699" ymax="4152028.76378653">
    <esri:SpatialReference wkid="3857"/>
   </esri:Extent>
  </esri:extent>
  <esri:ArcGISDynamicMapServiceLayer id="comm_layer" url="http://10.2.8.73/ArcGIS/rest/services/ZNET_Public/city_maskForExtent/MapServer"/>
 </esri:Map>

</s:Application>

What am I doing wrong?

Thanks,
Jason

Re: Populate combobox with a layer from a map service.

DasaPaddock — Wed, 08 Dec 2010 18:29:19 GMT

In my sample I'm putting the Graphics into the dataProvider. You're creating new Objects with a data property that points to the Graphic, so in your change handler try:

var extent2:Extent = Graphic(cmb.selectedItem.data).geometry.extent;

Re: Populate combobox with a layer from a map service.

JasonLevine — Wed, 08 Dec 2010 18:43:49 GMT

That makes complete sense. Thank you Dasa, and Robert, for your help with this.

-Jason

Re: Populate combobox with a layer from a map service.

LemvigKommune — Fri, 10 Dec 2021 22:30:08 GMT

Hi all

i've used this code and put it into a widget, with the corresponding xml-file.

and it's working well with just one Url, but i've would like it to iterate over more urls and put it all into the same arraycollection, but that i can't get to work.

this is a part of the xml-file.

<layer>
 <layerurl>http://gis.rksk.dk/ArcGIS/rest/services/AdresseLokalplan/MapServer/0</layerurl>
 <layeroutfield>ADR_NR_POST</layeroutfield>
 <layerzoomscale>1500</layerzoomscale>
</layer>

and this is a part of the mxml-file.

                                var lyrList:XMLList = configXML..layer;
    for (var i:int = 0; i < lyrList.length(); i++)
    {
     layerURL = lyrList.layerurl;
     layerOutField = lyrList.layeroutfield;
     layerZoomScale = lyrList.layerzoomscale;
    
    var comboQueryTask:QueryTask = new QueryTask();
    comboQueryTask.url = layerURL;
    comboQueryTask.useAMF = false;
    var comboQuery:Query = new Query();
    comboQuery.returnGeometry = true;
    comboQuery.where = "1=1";
    comboQuery.outFields = [layerOutField];
    comboQuery.outSpatialReference = map.spatialReference;
    comboQueryTask.execute(comboQuery);
    comboQueryTask.addEventListener(QueryEvent.EXECUTE_COMPLETE, onQueryComplete);
}

private function onQueryComplete(event:QueryEvent):void
   {
    var featureSet:FeatureSet = event.featureSet;
    for each (var graphic:Graphic in featureSet.features)
    {
     var fieldValue:String = graphic.attributes[layerOutField].toString();
     results.addItem({label: fieldValue, data: graphic});
    }   
    var graphicsExtent:Extent = GraphicUtil.getGraphicsExtent(featureSet.features);
    commExtent = graphicsExtent;    
   }

when i put more <layer> into the xml-file it fails

how do i get it to run the onQueryComplete function after each iteration ?

Thx in advance

Mads Gren
Lemvig
Denmark

Re: Populate combobox with a layer from a map service.

GeorgiannaStrode — Wed, 22 Dec 2010 19:14:16 GMT

Hi Paddock:

I tried your sample codes but it does not work well in my case.

I replaced STATE_NAME in your codes with the field name I want to query in, and replace the two urls with the url of the specific layer where the field is in, and the url of the map server. When I run it and click the icon, it keeps spinning. I dont know which part I am doing wrong.

I would really appreciate it if you could help me on that.

Re: Populate combobox with a layer from a map service.

JuneAcosta — Wed, 29 Dec 2010 14:32:56 GMT

Dasa,

I used the code you posted with a point layer. I get weird results with the zoom... does the code work for a point layer or just for a polygon layer?

june

Re: Populate combobox with a layer from a map service.

LemvigKommune — Wed, 29 Dec 2010 19:09:37 GMT

Hi June

I've got it to work with a autocompletebox from Hillel Corel (i think), i'll post the code and the widget in a few days, it works with points, lines and polygons.

i'm working on getting it to run multible queries, so that you can point to more than on layer in the config-file of the widget, so if you have a point-layer with adresses and a polygon-layer with parcel-numbers you can get it in the same list.

i'll hope for it to be complete just after new years eve.

Mads Gren
Lemvig
Denmark.

Re: Populate combobox with a layer from a map service.

DasaPaddock — Tue, 04 Jan 2011 22:35:34 GMT

Dasa,

I used the code you posted with a point layer. I get weird results with the zoom... does the code work for a point layer or just for a polygon layer?

june

My sample won't work as-is with a point layer since points don't have valid extents. See this code for an example of how to set the center and scale instead:

http://forums.arcgis.com/threads/20162-modify-Find-Task-Zoom-In-Results-Sample?p=65000&viewfull=1#post65000

Re: Populate combobox with a layer from a map service.

LemvigKommune — Wed, 12 Jan 2011 10:55:03 GMT

Dasa,

I used the code you posted with a point layer. I get weird results with the zoom... does the code work for a point layer or just for a polygon layer?

june

Hi June

I've put my AutocompleteSearch widget on arcgis.com - search for flex widget, hope it can help.

Mads Gren
Lemvig Kommune
Denmark