Wednesday, 17 November 2010

Fourth Task

 What is the current status of CSS?

CSS, Cascading style sheets which are used for presentation of XML and other documents written in a markup
language. As the current status of CSS is at level three it’s known as CSS3. Previous versions are 1.0, 2.0 and 2.1.

What is the current status of XSL?
The style sheet language solely made for XML documents, is Version 2.0, currently not all web browsers support XSL so it may be useful to use XSL in conjuction with CSS. However web browsers do accept XSLT, some accept XSL-FO and some dont. Both are components of XSL. Currently the versions for the components are:

XQuery 1.0
XPath 2.0
XSLT 2.0

What are the relative merits of CSS and XSL?
CSS is fairly simple to use, and is well known with web designers and web developers. CSS was developed alongside HTML which is why it’s mostly talked about with HTML. However its use is not only limited to HTML but can be used by XML by adding simple processing instructions. XSL is an XML application that has three components, XSL Transformations, XPath and XML FO making it far more powerful than using CSS with an XML document.

What are the implications of the concept of the document tree?
All XML documents when processed are processed into a hierarchical tree, that must start from the root element branching with the leaves. Every attribute and element in a document are represented in the tree hierarchy.


<?xml version="1.0" encoding="ISO-8859-1"?>
<note>  <to>Monica</to>
  <from>Brandy</from>
  <heading>Reminder</heading>
  <body>Reunion Special!</body>
</note>


This line is the root element, showing that the document is a note

These lines are the child elements

The below code explains for itself that all XML documents must have a root element, which branches out to the child elements and subchild elements and then must close with the root element. All elements can have attributes and text content.



 <root>
  <child>
    <subchild>.....</subchild>
  </child>
</root>

The below image represents an example of a CD entry in its hierarchical state

Refrences

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