How to Build a URL-Based Portlet with HTML Filtering (v2)

Oracle9iAS Portal Developer Kit
How to Build a URL-Based Portlet with HTML Filtering

PDK Release 2 (9.0.2 and later)

In the article How to Build a URL-Based Portlet, you learned how to create a portlet that displayed the content of a URL-based application. The example used in that article was Google.com. In some situations, you may wish to display selective HTML content from the application on which your portlet is based. For example, you may wish to filter out unwanted header or footer information before displaying the application content within the portlet. The PDK enables you to apply such HTML filtering to your URL-based portlets.

This article describes how to build a URL-based portlet that uses HTML filtering. It extends the Google.com sample from the article How to Build a URL-Based Portlet. Specifically, it uses HTML filtering to filter all content from Google except for the search form. The resulting URL-based portlet will just show the text box, the "Google Search" and "I'm Feeling Lucky" buttons, and the few other links associated with a Google search.

ASSUMPTIONS

You have successfully installed the PDK framework by following the article Installing the PDK Framework and Samples.
You understand the steps required to display a URL-based portlet on a portal page. Refer to the article Installing the URL-Based PDK Samples.

CREATING AN XML PROVIDER DEFINITION

Using a text editor, create an XML file for your portlet provider. Use the headerTrimTag and footerTrimTag tags to specify how to filter your HTML content. You may use the sample xml file below (you must change the httpProxyHost and httpProxyPort values to point to your own proxy server and port). Please refer to the article Understanding provider.xml for URL-Based Portlets for an explanation of the required XML tags and their functions.

After you have created the file, save it on your file system and call it "provider.xml".

<?xml version = '1.0' encoding = 'UTF-8'?>
<?providerDefinition version="3.1"?>
<provider class="oracle.portal.provider.v2.http.URLProviderDefinition">
<providerInstanceClass>oracle.portal.provider.v2.http.URLProviderInstance</providerInstanceClass>
   <session>true</session>
   <proxyInfo class="oracle.portal.provider.v2.ProxyInformation">
      <httpProxyHost>www-proxy.us.oracle.com</httpProxyHost>
      <httpProxyPort>80</httpProxyPort>
   </proxyInfo>
   <portlet class="oracle.portal.provider.v2.http.URLPortletDefinition">
      <id>1</id>
      <name>Google.com Portlet</name>
      <title>Google.com Portlet</title>
      <description>Display Google.com as a portlet.</description>
      <timeout>100</timeout>
      <timeoutMessage>Timed out waiting for Google.com Portlet.</timeoutMessage>
      <acceptContentType>text/html</acceptContentType>
      <showEdit>false</showEdit>
      <showEditToPublic>false</showEditToPublic>
      <showEditDefault>false</showEditDefault>
      <showPreview>false</showPreview>
      <showDetails>false</showDetails>
      <hasHelp>false</hasHelp>
      <hasAbout>false</hasAbout>
      <renderer class="oracle.portal.provider.v2.render.RenderManager">
         <contentType>text/html</contentType>
         <showPage class="oracle.portal.provider.v2.render.http.URLRenderer">
            <contentType>text/html</contentType>
            <charSet>ISO-8859-1</charSet>
            <pageUrl>http://www.google.com</pageUrl>
            <filter class="oracle.portal.provider.v2.render.HtmlFilter">
               <headerTrimTag><form</headerTrimTag>
               <footerTrimTag>/form></footerTrimTag>
            </filter>
         </showPage>
      </renderer>
   </portlet>
</provider>

DEPLOYING YOUR PROVIDER ON OC4J

To configure and deploy your provider on OC4J, please see the section called "Deploying Your Provider on OC4J" in the article, How to Build a URL-Based Portlet.

At this point, you are ready to register your provider and then add your new portlet to a page. Please follow the appropriate steps for doing this as described in the Installing the URL-Based Portlet Samples article.

Now that you have successfully created URL-based portlet that uses HTML filtering, please look for other portlet development articles that describe how to add extra features to your portlet, including single sign-on to external URL-based applications, XML filtering and more.

Here are some reference articles to help you better understand the architecture and technical details of URL-based portlets:

A Primer on URL-Based Portlets

Understanding the PDK Runtime for URL-Based Portlets

Understanding the provider.xml for URL-Based Portlets

Revision History:

January 2002