UKOLN AHDS Enhancing Web Site Navigation Using The LINK Element



Introduction

This document provides advice on how the HTML <link> element can be used to improve the navigation of Web sites.

The LINK Element

About

The purpose of the HTML <link> element is to specify relationships with other documents. Although not widely used the <link> element provides a mechanism for improving the navigation of Web sites.

The <link> element should be included in the <head> of HTML documents. The syntax of the element is: <link rel=”relation” href=”url”>. The key relationships which can improve navigation are listed below.

Table 1: Key Link Relations
Relation Function
nextRefers to the next document in a linear sequence of documents.
prevRefers to the previous document in a linear sequence of documents.
homeRefers to the home page or the top of some hierarchy.
firstRefers to the first document in a collection of documents.
contentsRefers to a document serving as a table of contents.
helpRefers to a document offering help.
glossaryRefers to 1 document providing a glossary of terms that pertain to the current document.

Benefits

Use of the <link> element enables navigation to be provided in a consistent manner as part of the browser navigation area rather than being located in an arbitrary location in the Web page. This has accessibility benefits. In addition browsers can potential enhance the performance by pre-fetching the next page in a sequence.

Browser Support

A reason why <link> is not widely used has been the lack of browser support. This has changed recently and support is now provided in the latest versions of the Opera and Netscape/Mozilla browsers and by specialist browsers (e.g. iCab and Lynx).

Since the <link> element degrades gracefully (it does not cause problems for old browser) use of the <link> element will cause no problems for users of old browsers.

An illustration of how the <link> element is implemented in Opera is shown below.

Browser Support For The <link>Element
Figure 1: Browser Support For The <link> Element

In Figure 1 a menu of navigational aids is available. The highlighted options (Home, Contents, Previous and Next) are based on the relationships which have been defined in the document. Users can use these navigational options to access the appropriate pages, even though there may be no corresponding links provided in the HTML document.

Information Management Challenges

It is important that the link relationships are provided in a manageable way. It would not be advisable to create link relationships by manually embedding them in HTML pages if the information is liable to change.

It is advisable to spend time in defining the on key navigational locations, such as the Home page (is it the Web site entry point, or the top of a sub-area of the Web site). Such relationships may be added to templates included in SSIs. Server-side scripts are a useful mechanism for exploiting other relationships, such as Next and Previous - for example in search results pages.

Further Information

Additional information is provided at
<http://www.ukoln.ac.uk/qa-focus/documents/briefings/briefing-10/>.