Recipe 21.2. Handling Web Services Responses

Problem

You want to retrieve the return value from a web services method.

Solution

Add a result event listener to the web services method object.

Discussion

Web services methods are complex objects of type mx.rpc.soap.Operation, to which you can assign event listeners. When a web services method returns a value, the method object dispatches a result event of type mx.rpc.events.ResultEvent. If you want to handle the event, you can add a listener to the method object. For example, if webService is a WebService object that maps to a web service that defines a method called getAverages( ), you can add a listener as follows:

webService.getAverages.addEventListener(ResultEvent.RESULT, onGetAverages);

You then call the method normally:

webService.getAverages(  );

When the listener is called, it is passed a ResultEvent parameter. The ResultEvent class defines a property called result that contains the return value. Assuming the getAverages( ) web services method returns an associative array with two properties called flash and actionscript, the following displays those values in a text area called textArea:

private function onGetAverages(event:ResultEvent):void {
    textArea.text = "The averages for Flash and ActionScript are " + 
event.result.flash + " and " + event.result.actionscript;
}