XML Feeds

The material in this section is based on the XML Specification. This
is not an exhaustive list of all the constructs which appear in XML; it
provides an introduction to the key constructs most often encountered in
day-to-day use.

(Unicode) Character

By definition, an XML document is a string of characters. Almost every legal Unicode character may appear in an XML document.

Processor and Application

The processor analyzes the markup and passes structured information to an application.
The specification places requirements on what an XML processor must do
and not do, but the application is outside its scope. The processor (as
the specification calls it) is often referred to colloquially as an XML parser.

Markup and Content

The characters which make up an XML document are divided into markup and content.
Markup and content may be distinguished by the application of simple
syntactic rules. All strings which constitute markup either begin with
the character "<" and end with a ">", or begin with the character
"&" and end with a ";". Strings of characters which are not markup
are content.

Tag

A markup construct that begins with "<" and ends with ">". Tags come in three flavors: start-tags, for example <section>, end-tags, for example </section>, and empty-element tags, for example <line-break/>.

Element

A logical component of a document which either begins with a
start-tag and ends with a matching end-tag, or consists only of an
empty-element tag. The characters between the start- and end-tags, if
any, are the element's content, and may contain markup, including other elements, which are called child elements. An example of an element is <Greeting>Hello, world.</Greeting> (see hello world). Another is <line-break/>.

Attribute

A markup construct consisting of a name/value pair that exists
within a start-tag or empty-element tag. In the example (below) the
element img has two attributes, src and alt: <img src="madonna.jpg" alt='by Raphael'/>. Another example would be <step number="3">Connect A to B.</step> where the name of the attribute is "number" and the value is "3".

XML Declaration

XML documents may begin by declaring some information about themselves, as in the following example.

http://local-solicitors.com/backlinks/forum002.xml

http://local-solicitors.com/backlinks/forum001.xml

http://local-solicitors.com/backlinks/education001.xml

By Andy Bolton