Web Services, Part II: Calling Service Methods: Handling the event.result Object - Doc JavaScript

Web Services, Part II: Calling Service Methods

Handling the event.result Object

If you don't specify an event handler in the callService() method, you can get the result object as a property of the event object. You first specify the onresult event handler like here:

<BODY ID="webServiceCallerBody" onresult="onWSresult()"
  style="behavior:url(webservice.htc)">

The event handler onWSresult() first checks to see if there was an error during the Web service call:

if (event.result.error)

Notice that the result object is a property of the event object. The event handler also checks that the event ID, as it came from the Web service, is identical to the ID returned by the callService() function:

if (iCallID==event.result.id)

With these two checks you can write an event handler that processes the result object, checks for errors and matching IDs, and prints the result value.

When checking for errors, the errorDetail object is quite handy. It is a property of the result object, and it includes detailed information about the Web service transaction. Here are its properties:

code. A machine-readable error code that corresponds to a specific invocation of the callService() method.
raw. This property exposes the raw Simple Object Access Protocol (SOAP) data packet returned by the Web Service after invoking the callService() method.
string. A human-readable error message that corresponds to a specific invocation of the callService() method.

The onWSresult() function in the following example reads the above parameters of event.result and prints them in an easier to understand fashion:

<SCRIPT language="JavaScript">
<!--
// All these variables must be global,
// because they are used in both init() and onresult().
var iCallID = 0;
var intA = 5;
var intB = 6;
function init() {
  service.useService("/services/math.asmx?WSDL","MyMath");
  iCallID = service.MyMath.callService("add", intA, intB);
}
function onWSresult() {
  if((event.result.error)&&(iCallID==event.result.id)) {
    var xfaultcode   = event.result.errorDetail.code;
    var xfaultstring = event.result.errorDetail.string;
    var xfaultsoap   = event.result.errorDetail.raw;
  } else if((!event.result.error) &&
    (iCallID == event.result.id)) {
           alert(intA + ' + ' + intB + ' = '
             + event.result.value);
         } else {
             alert("Something else fired the event!");
           }
}
// -->
</SCRIPT>
<BODY onload="init()">
<DIV id="service" STYLE="behavior:url(webservice.htc)"
  onresult="onWSresult()">
</DIV>
</BODY>

Next: How to define the calling buttons

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Web Services, Part II: Calling Service Methods: Handling the event.result Object - Doc JavaScript

Web Services, Part II: Calling Service Methods

Handling the event.result Object

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