XML abc

The genetics of XML - in order to understand, there are a number of different layers of recognition:

• That a text is written in a particular alphabet: that jaqsohy is written in the Greek alphabet, but that frukt is in the Cyrillic alphabet.
• Which particular language within a given alphabet: ‘frucht’ and ‘fruta’ are respectively German and Portuguese, but the word ‘fruit’ is in which language? English? French? And is frukt Russian or Ukrainian? This starts to become a little trickier.
• The meaning of the particular string of characters that make up a word. In the previous example, we could make a stab at meaning, and make the reasonable assumption that ‘frucht’, ‘fruta’, and ‘fruit’ all mean the same thing in each of the four languages (as does frukt once you recognize that it is pronounced ‘frucht’). On the other hand, what are ‘plod’, ‘toradh’, ‘hedelmä’ and ‘gyümölcs’? And in which languages?
• In the case of words with multiple meanings, the specific intended meaning can often be deduced from context. If the French word avocat appears in a recipe book it is most likely to have a different meaning than if the same word appears in a legal tome.

The context provides valuable insight into the probable meaning in a particular situation.

XML is a standard that is designed to encode information in a structured and accessible manner. It is a stable and reliable standard, vendor-independent and managed by the World Wide Web Consortium (W3C) and supported by a wide range of application and system vendors. A number of related standards, each using the core XML standard itself, have also been developed to respond to the specific demands of information management.

Some of these additional standards have been criticized for their apparent complexity and for creating a potentially tangled web of dependencies that might make their deployment less effective or less straightforward. This overlooks the fact that it is in the ‘genetic’ makeup of XML to be evolutionary, and even more standards are likely to emerge. As with DNA, the complexity of an XML standard or an XML document that uses it is proportional to the complexity of the ‘organism’ or the task for which it has been designed. For simple tasks and simple document structures, XML can be deployed in a simple manner – this is the principle of extensibility that we find in the standard’s name.

To understand the anatomy of XML, we will look at an analogy using natural human language. A single alphabet or character set can underpin a range of languages. This is important of course to keyboard manufacturers, typeface copyright holders and anyone involved in displaying information to an end user. A character set on its own, however, does not constitute a language, any more than being able to recognize individual letters constitutes an ability to understand a language that uses the character set.

The entirety of the rules regarding the structure of a text or document type, as well as additional functions including further processing, linking and management, are themselves all written in XML. This lingua franca can be applied not only to the sharing of semantics between information content, but also to the sharing of meaning in respect to content processing and management.
All aspects of an integrated information management system could therefore be expressed in XML, including:

• Managing your information and documents themselves – the essence of XML:
• storing data in a neutral format
• Applying your business rules: your business processing ‘middleware’
• Constraining format and structure of data and documents, plus workflow and access
• Controlling user interfaces and information display, including user control over display without affecting underlying content
• Extracting knowledge from information