Un portail sur iSeries

What Portals Look Like

A portal is a browser-accessible Web site that usually has a sign-on page (some have a separate page from the initial portal view; others show a "public" view of the portal pages prior to logging in) as well as a main portal page that consists of these items:

Portlets are really the heart of portal technology, and we'll look at them in more detail later on.

AS400 portal

Figure 1: Here's a typical user page from Nexus, an iSeries-centric portal. The user can work with content within many portlets on the page, including business applications, a calendar, and information from external sites such as UPS.

How Portals Are Implemented

Portals run on Web servers. They are available from major manufacturers and run on any platform, including UNIX, Windows, and iSeries. Some are written in Java and require a Java Web server such as WebSphere, WebLogic, or Apache Tomcat to run on. Some are open source and written in PHP running on Apache HTTP. On the iSeries, both Java-centric and CGI-based portal products are available.

The portal software is usually a combination of Web server code running "beneath" the Web server and Web server extensions in the form of plug-ins. For example, some portals include modules that extend the Apache HTTP server itself for handling user authorization to documents or links inside the portal.

Signing On

Portals almost always have a single sign-on (SSO) mechanism. The various authentication techniques include full LDAP registration, an authentication list, or a database file that contains users. On the iSeries, a portal may have the ability to validate users against a combination of the iSeries user profiles and the portal's own user database.

Customized Presentation of Content

Once users log on to the portal, what they see and have access to is tightly controlled by their authority level and their place within the hierarchy of the portal user base configuration. For example, portals often use the concept of groups or communities. Certain users may belong to the "customer" community but not the "employee" community, so when they log on, they see portlets, links, and navigation menus that apply only to customers. A Web portal administrator can control what content all users see, or group administrators may control content for members of their groups.

Portail iSeries

Click image to enlarge

Figure 2: Plumtree's portal lets users customize the preferences for their portal settings. It also provides comprehensive Web-based help that explains these customization features.

User Management

The ability to manage portal users or subscribers is an important product feature. Each portal product has its own slant on how to accomplish this. They all have some sort of Web-based administration tool, though, and this tool usually provides functionality to manage users or groups of users, set levels of authority for users, and restrict the pages and portlets users can see. The concept of groups of users is important for effectively managing availability of information or applications through a portal. In many cases, you may need to have groups within groups. For example, you may have a general group called Vendors as well as subgroups of specific companies within that group. This allows you to provide all vendors with access to information that is common for all vendors but to restrict specific documents to specific vendors where appropriate.

Common Interface for Accessing Information and Applications

Portals provide a common and consistent user interface for accessing information. In this way, you can think of a portal as a "Web desktop" that's analogous to the way you use Windows on a PC to access local resources. Common elements include drop-down menus, portlets, tree-style navigations, links, and document viewers for PDF, Word, or Excel files.

Portlets

Portlets are the core components of portals. A portlet is a visual container for content or an application. Its features usually allow you to move its location on your pages, to minimize it, or to edit common or unique properties associated with the portlet. Portal products usually let you create your own portlets or instances of portlets that are shipped with the product initially. For example, a portal may have a calendar portlet. With instance support, you could create multiple versions of the calendar portlet so that, for example, you could have a separate vacation schedule calendar or conference room booking calendar.

Most portals also let you secure portlets by users or groups of users, either to prevent complete access or to limit editing capabilities for that portlet by that user or group.

These are some typical applications shipped with portals:

Cross-Server Accessibility

Portals typically run on a single server or a cluster of servers. However, one of the strengths of portals is their ability to disseminate information from other servers. This is usually done with one of two general technological approaches:


The first method is the most straightforward; you simply create a portlet that references a URL from another site. The second method is more involved to implement, but it's also more interesting. This approach involves having your portlet act as a Web services consumer of a provider from some other server. For example, if currency exchange rates play an important role in the financial management of your company, you may subscribe to a currency exchange quotation service. You could create a portlet that initiates calls to this service periodically to get real-time exchange rates and then display them in the portlet. Usually, this is done via an XML document exchange, although the structure of the transmitted data is not really important. What is important, though, is that portals allow you to bring together in a common view information from disparate and wide-ranging sources.

Enterprise Content Management (ECM) with Portals

Much of the vital information of an organization may reside on network resources in your own organization. With portals, instead of having your users rely on mapped network drives to access documents, you can provide them with a convenient view of the content store while hiding the underlying physical structure. In other words, you can impose a virtual view of the collection of documents that more closely corresponds to how the users are most likely to navigate the information. For example, you may have a tree view of HR and corporate policy documents. Behind the scenes, these documents may be scattered all over (and published in many forms, such as HTML, Word, or PDF). The user, though, sees a meaningful visual structure for these documents. Usually, some kind of search facility is included with ECM portlets. Look for ones with specialized keyword searches, as they can help users be more successful in finding information.

Security Implementation in Portals

The two primary areas of portal security, as with Web applications in general, are authentication and authorization. Authentication takes place during the login process. Authorization occurs when a user tries to access a document within the portal. Some portal products provide Web server extensions that let you customize authorization within the portal to impose security at the Web server level. This prevents a devious user from entering a URL into the browser's location toolbar to access a protected document.

Benefits of Running an iSeries Portal

While you can implement portals on most any platform, using an iSeries-based portal offers several benefits:

The Future of Portals

Enterprise Information Portals are a relatively new technology. Emerging standards, particularly around Java-based portals, will make sharing of portlets between portal products easier. (JSR 168 is a published standard for writing Java-based portlets.)

Another interesting development is interaction between portlets in the same portal: As a user changes something in one portlet, it affects information in another portlet. IBM is using this effectively in WebSphere Portal, while another iSeries portal product is using this approach for document management.

In addition, the enthusiasm surrounding SOA will have a strong impact on the power of portals as information exchange between organizations becomes more prevalent.

Just as science fiction often becomes science fact, expect to see exciting things happening with portals in the near future. This new window into the world of electronic information is just starting to open.

If you're ready to get started with portals, consider investigating these companies and products: IBM WebSphere Portal, Plumtree, Microsoft Sharepoint, Sun Java System Portal Server, Vignette Portal, PHP Nuke, and BCD Nexus.

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