Creating an extent DropDownList

[JasonLevine]

Hello,
   I'm trying to create a bookmark drop down list in my flex app.  I've created the drop down bar with this code:

<s:DropDownList width="164" prompt="Select Your Community">
<s:ArrayCollection>
  <fx:String>Community #1</fx:String>
  <fx:String>Community #2</fx:String>
</s:ArrayCollection>
</s:DropDownList>

My two questions are:
1) Where do specify the extent values (minx, miny, etc...) for each community? Do I do that within the string tag, or do I create a separate xml file with the data?
2) How do I add a function that zooms the map to the extent specified when a city is selected from the drop down list?

Thanks for your help,
Jason

[KenBuja]

The first line in the try block (line 38) should be

var loader:URLLoader = URLLoader(event.target)

[KenBuja]

Have you stepped through the code using the debugger? I would put a breakpoint at the If statement and check your variables to make sure you have properly read in the XML file. I've attached a screenshot of the XML list variable I get from my code. In this particular project, I'm not using the Extents node, but I've expanded out one of the nodes I am using (which also populates a combobox)

[JasonLevine]

Hi Ken,
    I managed to compile it all without any errors, however, the values in the xml don't seem to be loading into the Combobox.  where do I call the init() function?  Is it something like this?:

<?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:mx="library://ns.adobe.com/flex/mx"
      xmlns:esri="http://www.esri.com/2008/ags" 
      xmlns:container="com.esri.ags.script.*" 
      initialize="init()" >

[KenBuja]

I have that in the creationComplete event

[JasonLevine]

I added it to the creationComplete event, and the xml values still don't load in the combobox.  See anything wrong with my code?

Thanks,
Jason

Here are the functions:

//the following two functions import the bookmarks.xml file
   private var xmlParameters:XML;    
   public var xmlProjectParameters:XMLList;
   
   private function init():void
   {
    var xmlLoader:URLLoader = new URLLoader();
    xmlLoader.load(new URLRequest("bookmarks.xml"));
    xmlLoader.addEventListener(Event.COMPLETE,init_onComplete);
   }
   
   private function init_onComplete(event:Event):void
   {
    var extentArray:ArrayCollection = new ArrayCollection;
    
    try
    {
     var loader:URLLoader = URLLoader(event.target)
     xmlParameters = new XML(loader.data)
     xmlProjectParameters = xmlParameters.communities.(@id=="communities")
     
     if (!(xmlParameters.extents == undefined))
     {
      dropdown.visible = true;
      for (var i:int = 0; i < xmlProjectParameters.extents.extent.length(); i++)
      {
       extentArray.addItem({label:xmlProjectParameters.extents.extent.@name.toString(), xmin: xmlProjectParameters.extents.extent.@xmin.toString(), ymin: xmlProjectParameters.extents.extent.@ymin.toString(), xmax: xmlProjectParameters.extents.extent.@xmax.toString(), ymax: xmlProjectParameters.extents.extent.@ymax.toString()});
      }
      dropdown.dataProvider = extentArray;
      
     }
    }
    catch(e:Error)
    {
     Alert.show("Error: " + e.message);
     return;
    }
   }
   
   //Zoom to your community tool   
   public function change():void
   {
    var extent:Extent = new Extent(Number(dropdown.selectedItem.xmin), Number(dropdown.selectedItem.ymin), Number(dropdown.selectedItem.xmax), Number(dropdown.selectedItem.ymax))
    myMap.extent = extent;
   }

Here is my bookmarks.xml file:

<bookmarks>
  <communities id="communities">
 <extents>
   <extent name="Community #1" xmin="-13181026" ymin="4010315" xmax="-13164974" ymax="4017443"/>
    </extents>
  </communities>
</bookmarks>

[JasonLevine]

Problem solved.  I removed the try and catch and shortened it up a bit:

private function init_onComplete(event:Event):void
   {
    var extentArray:ArrayCollection = new ArrayCollection;
    var loader:URLLoader = URLLoader(event.target)
    xmlParameters = new XML(loader.data)
    xmlProjectParameters = xmlParameters.communities.(@id=="communities")
    for (var i:int = 0; i < xmlProjectParameters.extents.extent.length(); i++)
    {
    extentArray.addItem({label:xmlProjectParameters.extents.extent.@name.toString(), xmin: xmlProjectParameters.extents.extent.@xmin.toString(), ymin: xmlProjectParameters.extents.extent.@ymin.toString(), xmax: xmlProjectParameters.extents.extent.@xmax.toString(), ymax: xmlProjectParameters.extents.extent.@ymax.toString()}); 
    }
    dropdown.dataProvider = extentArray;
   }

Thanks for your help,
Jason

[MarcGuidry]

Hi,
Sorry to dig up an old thread but...
I've got my combo box working but I was wondering how to get the combo box selection to reset after a selection has been made?  That way you can select the first extent, pan around, and go back to that first extent without having to select a different extent first.

[EvelynHernandez]

Add the features from the last choosen to an arraylist or arraycollection variable, then when u wanna go back u will pass those values to the zoom extent.

[denverweston]

Hey Jason,

Do you have the updated code for this drop down?  My combobox will still not populate using the code above.