2.2 Integration techniques and development options

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2.2 Integration techniques and development options

Developers wishing to expose Domino content and functionality within a portal environment have many integration techniques at their disposal. The integration techniques presented in this book have been categorized into four main groups, called development options. These development options are:

  1. Using existing portlets

  2. Domino JSP tag library

  3. Java

  4. Portlet builders

The integration techniques within each development option share many similar characteristics. These characteristics include:

  • The technologies and technical skill set required for implementation

  • Development time

  • The developer's level of control over the application functionality

This section provides a brief overview of the characteristics of each development option and outlines the integration techniques found within each option. Further details and implementation examples are provided for each option in subsequent chapters.

2.2.1 Using existing portlets

Note 

Chapter 3 provides a full description of this development option.

Description

There are many general-purpose portlets provided with WebSphere Portal that can be used to access Domino applications. Other general purpose portlets are available from third-party sources. If a portlet is available that meets your Domino application's needs, this is the most expedient option.

Advantages

Using an existing portlet is by far the simplest option to implement and requires the least amount of development time. Developers do not need to be familiar with Java or WebSphere Portal, or often even Domino development technologies, to implement this option.

Limitations

The developer is limited to the functional capabilities provided by the portlet being used. Customizing the functionality of an out-of-the-box or third party portlet is not always possible.

Integration Techniques

QuickLinks portlet

The QuickLinks portlet simply stores a configurable collection of URLs and URL labels. It is very easy to configure and deploy.

Applicable portlet patterns

The QuickLinks portlet is ideal for implementing the Link portal pattern.

Web Page portlet (IFrame)

By using the <IFRAME> tag to create a nested frameset, the WebBrowser portlet allows us to embed almost any HTML content, including Web-enabled Domino applications, within the portal context. It is a quick and easy way to provide custom content within a portal page, but has all of the caveats of using framesets in general.

Applicable portlet patterns

If framesets can be tolerated, the WebBrowser portlet can be used for the Link, Display, and Hybrid patterns. The behavior of content in this portlet is essentially outside of the portal framework, and should not be used if access to portal resources or inter-portlet communication is required.

Web Clipping portlet

The Web Clipping portlet takes content from a specified URL, extracts a selected subset of this Web page, and embeds the content into a portlet. Unlike the Web Page portlet, content is rendered within the portlet context. However, this portlet does not always work as intended with existing HTML. For example, JavaScript does not always function as intended, and much of the header information is lost.

Applicable portlet patterns

Simple Link or Display portlets can be implemented using the Web Clipping portlet.

Notes View portlet

The Notes View portlet provides access to a specified view in any Domino database. It is simple to implement and can be applied to any application. However, the interface cannot be customized.

Applicable portlet patterns

The Notes View portlet can be used to implement a basic Display portal pattern. However, it should not be used if any customized interface or additional functionality is required.

XML helper and RSS portlets

The Rich Site Summary (RSS) news format is a simple, common format for delivering news to portals and other Web sites. By default, the RSS Portlet renders XML data that conforms to the RSS DTD. However, it can be easily configured to render any XML data using any XSLT stylesheet.

Currently, the RSS portlet only allows for a single, static URL to be specified when the portlet is configured. This significantly reduces the usefullness of this portlet as an effective integration technique.

An XSLT stylesheet can be written to render DXL, Domino's native XML format. Or, a custom Domino view or agent can be developed that generates XML in the RSS format.

An XML/XSL helper portlet can be configured to get the XML from Domino and format it for presentation. This set of methods produces portlets by simply modifying your Domino application to serve up XML to the XML/XSL helper portlet. The style sheet used to render the view creates an HTML table out of the Domino XML (DXL) resulting from a ReadViewEntries request to the Domino database.

Applicable portlet patterns

Link and Display portlet patterns using a very small data set can be implemented using this RSS portlet. XML/XSL helper portlet can be used to implement Link and Display portlet patterns.

Using multiple existing portlets together

By combining the Web Clipping and Web Page portlets with some custom JavaScript and Domino development, it is possible to create a basic portal application which implements the integrated portlet pattern without custom Java or JSP development. The main advantage of this integration technique is that it is relatively quick and easy to implement. Its main limitation is that the developer is tied to the features provided by the portlets being used.

Applicable portlet patterns

Display portlet pattern and Integrated portlet pattern (with limited functionality)

2.2.2 Domino JSP tag libraries

Note 

Chapter 4 provides a full description of this development option and its integration techniques.

If the functionality provided by existing portlets is not adequate for your Domino portal integration requirements, the Domino JSP tag library is a good option to consider. JSPs and the Domino JSP tag library provide a rich set of development options that are quicker and easier to implement than the Java development option discussed in Chapter 5.

Note 

At the time of writing, the Domino JSP tag library implementation did not fully support a portal environment. Refer to the release notes of the new Domino versions to see if the support has been added.

Integration Techniques

Domino JSP Tag Libraries

JSP Tag Libraries provide developers with a quick and easy technique for giving a Web application the ability to incorporate complex Lotus Domino interactions, simply by adding custom Domino JSP tags to a JSP page. Because the WebSphere Portal framework and JSPs are both based on the J2EE environment, a developer can easily use Domino JSP tags to expose Domino data and functionality in a WebSphere Portal portlet.

A key drawback of the Domino JSP tag library is that it does not currently support session pooling for connections to Domino servers. This can result in performance limitations for heavily used portal applications.

Applicable portlet patterns

Link and display portal patterns can be implemented using the JSP tags, but are often more easily implemented using techniques described earlier in this chapter. Generally JSP tags are used when implementing integrated and migrated portlets.

A great number of options and techniques are available to the developer. Some of the options are:

  • J2EE development

  • JSPs

  • JSP tags

  • Custom Domino JSP tags

  • Click to Action

  • Collaborative components

2.2.3 Developing Domino portlets using Java

Note 

Chapter 5 provides a full description of the Java development option and its integration techniques.

While JSP tags provide developers significantly more power than using existing portlets, developers may still require specific functionality that is difficult or not possible to implement within the JSP tag model. Pure Java coding overcomes the development limitations of other integration technologies or options.

Java is the base programming language, ultimately used by all portlets running on WebSphere Portal. You are not limited by the functionality or the user interactions provided by portlet builders or existing portlets, or by any scalability limitations. When you are creating your own Java programs, you can deal with all of these issues, as well as others.

The disadvantages of developing in Java are that extensive Java programming skills and portlet programming skills are required, and in many cases the development time can be a lot longer than for other integration techniques.

A great number of options and techniques are available to the Java developer. Some of the options are:

  • The WebSphere Portlet API

  • Domino Java API, handling Rich Text in Domino

  • Corba mechanism and IIOP access to Domino databases

  • Implementing object pooling

  • Using the Struts framework with Domino and WebSphere Portal

  • Using JavaBeans

  • Portlet logging using the server-based log and log4j

2.2.4 Portlet builders

Note 

Chapter 6 provides a full description of the Portlet Builder development option and its integration techniques.

This option covers the tools and technologies available in the marketplace that attempt to bridge the gap between the limitations of the use of existing portlets and the complexity of the custom Java development options. It focuses on the technology offerings from vendors including IBM, Bowstreet, Conet, and others.

Portlet builder technologies provide a "middle-ground" approach to portlet development. They offer significantly more development capabilities than the use of existing portlet option. In addition, they promise a shorter development time and require less in-depth knowledge about custom portlet development than the more advanced custom development options of JSPs and Java.

The portlet builders that are included in our detailed discussion in Chapter 6 are:

  • IBM Portlet Builder for Domino

  • Bowstreet Portlet Factory for WebSphere

  • Conet Portlet Factory for Domino

Other portlet builders introduced in that chapter are:

  • Aptrix Portlet Connector

  • Sofor Interactive Portlet Builder for Domino

These tools vary in capability, development approach, user interface, strengths, and weaknesses.



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Portalizing Domino Applications for Websphere Portal
Portalizing Domino Applications for Websphere Portal
ISBN: 0738499811
EAN: 2147483647
Year: 2003
Pages: 103
Authors: IBM Redbooks

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