IBM Version 5 manual XML Pointer

￿“Choice 1: Beef Vindalooo" resolves to the URI

"http://airlines.org/mealchoices/choice1.xml"

￿“Choice 2: Chicken Laksa" resolves to the URI

"http://airlines.org/mealchoices/choice2.xml"

￿"Choice 3: United Airlines Burger" resolves to the URI

"http://airlines.org/mealchoices/choice2.xml"

As in XML, only Unicode characters are allowed in xml:base. But for the URI, non-ASCII characters, except for the hash, percentage and square brackets, are disallowed. All disallowed characters can be used provided they are converted to UTF-8 or hexadecimal notation of the byte value, or if the character is replaced by the character sequence.

The URI is resolved in the following priority:

1.The URI entry specified in the document

2.The URI of the encapsulating entity

3.The base URI is the URI used to retrieve the entity, or is defined by the application.

The base URI may consists three parts in this order:

a.The base URI dictated by the xml:base attribute

b.The base URI of the element’s parent

c.The base URI of the document entity containing the element

It is best to provide an xml:base attribute as close to where the relative paths are specified. If not, the xml:base attribute of the parent document comes into affect. If the parent document is not available, then there might by difficult to determine the absolute URI. For best results, the xml:base value should be provided either directly or via default attributes declared in the internal subset of the DTD. Visit W3C Web page to read more:

http://www.w3.org/TR/xmlbase/

XML Pointer

The XML Pointer specification is the final part of the XLink specification. Where XLink governs how you can insert links into your XML document and where the link can point to anything, XPointer allows the user to point to specific part of the document or a range, or area of the document. The user can then link the address from one point of the document to another point in the same document.

IN HTML, using the ‘A’ and ‘IMG’ allows you to point from one document to another, and only to a pre-determined spot. In an XML document, given its tree structure, you should be able to navigate down to a child element or to a part of a tree or from one part of a tree to another part of the tree.

Chapter 2. Technologies in XML 29