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Using the TemperatureService object

This line of code creates a property called

webServiceSend

that points to the

send()

function. This

procedure makes it possible to redefine

send()

without losing the original functionality:

TemperatureService.prototype.send = function (sZipcode) {

this.zipcode = sZipcode;

return this.webServiceSend();

};

The first thing the new

send()

method does is assign the

zipcode

property. Then, it returns the

result of the

webServiceSend()

method (which is a call to the original

send()

method). The

TemperatureService

object can be used like this:

var oService = new TemperatureService();

var fResult = oService.send(“90210”);

alert(“Temperature is “ + fResult + “degrees”);

Using the TemperatureService object

To recreate the temperature example one more time, the code is much simpler:

<html>

<head>

<title>Cross-Browser Web Service Example</title>

function callWebService() {

var sZip = document.getElementById(“txtZip”).value;

var oService = new TemperatureService();

var fResult = oService.send(sZip);

alert(“It is currently “ + fResult + “ degrees in that zip code.”);

}

</script>

</head>

<body>

</p>

</body>

</html>

As you can see, the

callWebService()

function is greatly simplified in this example. The zip code is

obtained from the text box; then the

TemperatureService

object is created, and the zip code is passed

into the

send()

method, which returns the temperature in degrees. An alert is then displayed indicating

the temperature.

529

Web Services

20_579088 ch17.qxd 3/28/05 11:42 AM Page 529