Web Services, Part X: Consuming the StockQuote - Doc JavaScript

Web Services, Part X: Consuming the StockQuote

In this column we continue our series on Web services. In Part I, we introduced you to this hot topic. In Part II, we showed you how to call Web services. In Part III, we presented the WebService behavior and its four supported methods. In Part IV, we continued our coverage of the WebService behavior by describing its objects and properties. In Part V, we dove into XML and XSLT. In Part VI, we started a miniseries on how to load and manipulate XML files from JavaScript. We continued this miniseries in Part VII, where we focused on the DOMDocument's nodes and node types. In Part VIII, we examined the world of document type definitions (DTDs). In Part IX we covered techniques for finding nodes on the DOMDocument tree. In this column, you'll exercise concepts and ideas from previous columns, by consuming the StockQuote Web service.

In this column we'll show you how to use the StockQuote Web service with the webservice DHTML behavior. We'll teach you how to assign a friendly name to the webservice behavior, how to call it, and how to handle its response. The Web service returns an XML object which we transform to HTML with an XSL file. We'll show you how to write the call and respond functions, what the XML response looks like, and how to write the XSL code that converts the XML response to HTML. Try it now. After the page loads, click the Get Quotes button and then wait patiently for a few seconds until a table shows up with the stock quote details of YHOO, IBM, and MSFT. This Web services example works only in IE5.5 and up. To get this page to work from our server, you need to enable the access data sources across domains option. First, invoke Internet Options from the browser's Tools menu. Select the Security tab and the Internet icon in the top window. Click the Custom Level button. Go to Miscellaneous->Access data sources across domains, and select Enable or Prompt. You need to enable this access because the page on our server is communicating with the Web service StockQuote in a different domain (eggheadcafe). If you are still experiencing difficulties in calling callstockquote.html from our server, download the zip file below and install all of the files on your client computer.

In this column you will learn:

• How to write the HTML section of the caller
• How to write the request handling function
• How to write the response handling function
• How to interpret the XML response
• How to convert the XML response to HTML

You can download all of the files shown here (callstockquote.html, webservice.htc, and stock.xsl) directly from this zipped file.

Next: How to write the HTML section of the caller