December 2, 2001 - Calling the EchoString Web Service | WebReference

December 2, 2001 - Calling the EchoString Web Service

Yehuda Shiran December 2, 2001
Calling the EchoString Web Service
Tips: December 2001

Yehuda Shiran, Ph.D.
Doc JavaScript

When calling a Web service, you need to pay close attention to its expected input data type. When the input is of type string, you may send a quoted string or a number. You send the input string to the Web service by assigning the third parameter of the callService() method. The following call will be successful:

iCallID = webServiceCallerBody.echo.callService(handleResult, "echoString", 
  "Asynchronous Call");
As well as the following call:

iCallID = webServiceCallerBody.echo.callService(handleResult, "echoString", 5.6);
If you send a non-quoted string, the JavaScript interpreter will assume it is a variable and will complain that the variable is undefined. Therefore, the following line of code will yield an error:

iCallID = webServiceCallerBody.echo.callService(handleResult, "echoString", abc);
Learn more about Web services in Column 96 (Web services, Part I: Introduction) and Column 97 (Web Services, Part II: Calling Service Methods).

Here is an HTML file that demonstrates calling a Web service. Copy it to your local disk, together with the WebService behavior (webservice.htc):

<HTML>
<BODY ID="webServiceCallerBody" onload="loadService()" 
  STYLE="behavior:url(webservice.htc);background-color:peachpuff;color:brown;font-size:18">
<SCRIPT LANGUAGE="JavaScript">
<!--
function loadService() {
	webServiceCallerBody.onserviceavailable = enableServiceCall;  //Used for the synchronous call.
	webServiceCallerBody.useService(
	  "https://soap.bluestone.com:80/interop/EchoService/EchoService.wsdl","echo");
}
function callAsynch() {
	iCallID = webServiceCallerBody.echo.callService(
	  handleResult, "echoString", "Asynchronous Call");
}
function callSynch() {
	var co = webServiceCallerBody.createCallOptions();
	co.funcName = "echoString";
	co.async = false;
	var oResult = webServiceCallerBody.echo.callService(co, "Synchronous Call");
	handleResult(oResult);
}
function enableServiceCall() {
	b2.disabled = false;
}
function handleResult(res) {
  if (!res.error) {
    alert("Successful call. Result is " + res.value);
  }
  else {
    alert("Unsuccessful call. Error is " + res.errorDetail.string);
  }
}
// -->
</SCRIPT>
<HR><H4>Calls to an echo service</H4><HR><BR><BR>
<BUTTON ID="b1" onclick="callAsynch()">Call Asynchronously</BUTTON><BR><BR>
<BUTTON ID="b2" onclick="callSynch()" disabled>Call Synchronously</BUTTON><BR><BR><BR><BR>
<A HREF="https://www.xmethods.net/ilab/">Interop Testing Site</A>
</BODY>
</HTML>