XML in a Nutshell, 3rd Edition

Link Behavior

So far, we’ve been careful to talk in the abstract. We’ve said that an XLink describes a connection between two resources, but we haven’t said much about how that connection is presented to the end user or what it makes software reading the document do. That’s because there isn’t one answer to these questions. For instance, when the browser encounters a novel element that uses an http URL, clicking the link should probably load the text of the novel from the URL into the current window, thereby replacing the document that contained the link. Then again, maybe it should open a new window and show the user the new document in that window. The proper behavior for a browser encountering the novel element that uses an isbn URN is even less clear. Perhaps it should reserve the book with the specified ISBN at the local library for the user to walk in and pick up. Or perhaps it should order the book from an online bookstore. In other cases something else entirely may be called for. For instance, the content of some links are embedded directly in the linking document, as in this image element:

<image width="248" height="173" xlink:type="simple"
       xlink:href="http://www.turing.org.uk/turing/pi1/sark.jpg" />

Here, the author most likely intends the browser to download and display the image as soon as it finds the link. And rather than opening a new window for the image or replacing the current document with the image, the image should be embedded into the current document.

Just as ...