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:: Web Services :: XWebNews :: Implementation Guides ::

How-To Syndicate (RSS 2.0) Your News Using XSLT

The procedures in this implementation guide require that you have some knowledge of XML, XSLT and ASP.NET web development with the Microsoft Visual Basic.NET development tool.

The steps in this "how-to" implementation guide are:

• Add a "Web Reference" to the XWebNews Web Service
• Add a "Web Form" to the web application
• Write code in the "Codebehind" of the web form to retrieve News Articles by consuming the XWebNews Web Service
• Implement an XML Web Control to display the News Articles

To download the source code for this "how-to" implementation guide, as well as for additional hints and tips, please read our Final Notes.

Add a "Web Reference" to the XWebNews Web Service

• In your web project, add a Web Reference to the XWebNews web service. Here are 2 ways you can accomplish this:

  • Browse the Solution Explorer, right click on References and select Add Web Reference... from the drop down menu.
  • From the File Menu, select Project - Add Web Reference....

• The Add Web Reference pop-up window will open. In the URL textbox, enter the following URI:

  http://ws.xwebservices.com/XWebNews/XWebNews.asmx?wsdl

• Hit the Enter key or click the Go button located to the right of the URL textbox.
• Change the Web reference name to XWebNews for easier reference.
• Click the Add Reference button to complete this step.

Add a "Web Form" to the Web Application

• In your web project, add a Web Form. This Web Form will contain the RSS Feed we will use for syndicating the News Articles. Here are 2 ways you can accomplish this:

  • Browse the Solution Explorer, right click the name of your project, and select Add - Add Web Form....
  • From the File Menu, select Project - Add Web Form....
• Change the Name textbox in the Add New Item pop-up provided to rss.aspx.

Write code in the "Codebehind" of the web form to retrieve News Articles by consuming the XWebNews Web Service

Based on the documentation for the XWebNews web service, in order to successfully consume the web service, we will need to authenticate first using SOAP Headers. Here's how:

• Open the "Codebehind" of the rss.aspx web form we added to the web project in the previous step.

• Since the web service requires SOAP Headers for authentication purposes, we must first create a new instance of the class representing the SOAP Header and then populate the SOAP Header values:

  ' handle authentication
  Dim objAuth As New XWebNews.AuthHeader
  objAuth.LoginName = "<my_login_name>"
  objAuth.Password = "<my_password>"

  NOTE***: Instead of hard-coding the LoginName and Password values, you may want to dynamically read them from the web.config file (LOGIN_NAME and PASSWORD must be added to the <AppSettings> section of the web.config file):

  objAuth.LoginName = System.Configuration.ConfigurationSettings.AppSettings("LOGIN_NAME")
  objAuth.Password = System.Configuration.ConfigurationSettings.AppSettings("PASSWORD")

• Next, we need to create a new instance of the proxy class and assign the SOAP Header object to the member variable of the proxy class representing the SOAP Header:

  'create the XWebNews web service proxy
  Dim objNews As New XWebNews.XWebNews
  objNews.AuthHeaderValue = objAuth

• We are now ready to call the method on the proxy class that communicates with the Web Service method and returns the News Article records we want in the RSS feed. For this how-to guide we chose to display the newest 10 Articles already live:

  'store the result in a variable
  Dim strNewsXML As String = objNews.LoadArticles(#1/1/1900#, Now, 1, 10)

Implement an XML Web Control to display the News Articles

In the "Codebehind" of the rss.aspx web form, we need to declare an XML Web Control. Next, we need to set its DocumentContent property to the XML string we received from the SOAP method. Finally, we set the TransformSource property to the path of an XSL Stylesheet (please click here for an example) that will transform the XML string into the RSS 2.0 format we desire:

• Declare the XML Web Control in the Codebehind:

  Protected xmlNews As System.Web.UI.WebControls.XML

• Set the XML Web Control's DocumentContent property to the XML string from the previous step:

  'set the DocumentContent property
  xmlNews.DocumentContent = strNewsXML

• Set the XML Web Control's TransformSource property to the path of the XSL Stylesheet (substitute your own path):

  'set the TransformSource property
  xmlNews.TransformSource = "news.xslt"

The last thing we need to do in the "Codebehind" of the webform is set the web form's ContentType property to "text/xml" and the ContentEncoding property to UTF8:

Response.ContentType = "text/xml"
Response.ContentEncoding = System.Text.Encoding.UTF8

The only thing in the HTML Editor of the rss.aspx web form should be the declaration for the XML Web Control:

<asp:XML ID="xmlNews" Runat="server" />

Final Notes

The source code for this "how-to" implementation guide can be downloaded by clicking the link below (zip file, contains the source code for all "how-to" implementation guides for the XWebNews Web Service)

XWebNewsClient.zip

You may use the other SOAP methods exposed by the XWebNews web service to syndicate all your News Articles or News Articles posted within a specific date range (archive).

It's always good practice to implement a Try...Catch... error handling technique to handle some or all possible errors that may occur while the code is executing. We strongly recommend that you implement such a technique.