Tuesday, December 15, 2009


I've been working for some time now with the Openscales AS3 library. Finally we have a Flex GIS client. The library is work in progress, but already offers really nice features and functions. At some point soon I will share some of my work and code. I've been busy customising core functional elements including adding Yahoo and Bing baselayers, restricting WFS rendering to scale, allowing WFS layers to be turned on and off, custom styling the interface and components. More to come.

Flex Web Services

I don't often use web services in Flex. But recetly found need to dip my toe in. The following I thought was an exellent simple example. taken from http://www.cflex.net/showFileDetails.cfm?ObjectID=582. Thanks Tracy.

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" xmlns="*"
creationComplete="getWeather()" >
import mx.controls.dataGridClasses.DataGridColumn;
import mx.rpc.events.ResultEvent;
import mx.managers.CursorManager;
import mx.controls.Alert;

default xml namespace = "http://www.webservicex.net"; //necessary to access the xml elements easily

[Bindable]private var _xmlResult:XML; //holds the result xml
[Bindable]private var _xlDayData:XMLList; //dataProvider for the day weather dataGrid
[Bindable]private var _sPlace:String;

/** invokes the web service operation to get the weather */
private function getWeather():void

/** called by the WebService result event. Sets the dataProviders as necessary */
private function onResult(oEvent:ResultEvent):void
_xmlResult = XML(oEvent.result);
var xmlResultNode:XML = _xmlResult.GetWeatherByZipCodeResult[0];
var xmlDetailsNode:XML = xmlResultNode.Details[0];
outputInfo.text = _xmlResult.toXMLString();
_sPlace = xmlResultNode.PlaceName.text() + ", " + xmlResultNode.StateCode.text();
_xlDayData = xmlDetailsNode.WeatherData;

/** labelFunction for DataGrid. It seems that the namespace on the xml makes
* using the DataGridColumn dataField not work. At least I couldn't get it to work. */
private function lfDayData(oItem:Object, dgc:DataGridColumn):String
var sReturn:String = "";
var xmlItem:XML = XML(oItem); //get the item object cast as an xml object
var sHeaderText:String = dgc.headerText; //get the header text for this column
switch (sHeaderText) //logic to determine which node to get the data from
case "Day":
sReturn = xmlItem.Day.text();
case "High":
sReturn = xmlItem.MaxTemperatureF.text();
case "Low":
sReturn = xmlItem.MinTemperatureF.text();

return sReturn;


<mx:WebService id="WS" wsdl="http://www.webservicex.net/WeatherForecast.asmx?WSDL"
fault="Alert.show(event.fault.faultString), 'Error'"
result="onResult(event)" >

<mx:operation name="GetWeatherByZipCode" resultFormat="e4x" >

<mx:Panel title="WebService Example" height="75%"
paddingTop="10" paddingBottom="10" paddingLeft="10" paddingRight="10" id="myPanel">
<mx:TextArea x="200" width="400" height="250" id="outputInfo" />
<mx:Label width="100%" color="blue"
text="Enter a zip code."/>
<mx:TextInput id="zipcode" text="30117"/>
<mx:Button label="Get weather" click="getWeather()"/>

<mx:Text id="txtPlace" htmlText="{_sPlace}"/>
<mx:DataGrid dataProvider="{_xlDayData}" height="180">
<mx:DataGridColumn labelFunction="lfDayData" headerText="Day" width="200" />
<mx:DataGridColumn labelFunction="lfDayData" headerText="High" width="100" />
<mx:DataGridColumn labelFunction="lfDayData" headerText="Low" width="100" />