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Created using a WYSIWYG XHTML editor

I originally created the document as an XHTML document using a WYSIWYG XHTML editor that behaves muchlike a word processor. (If you don't know what WYSIWYG means, Google it.) Of course, the document has since undergone quite a lot of editing so the finalXHTML version probably doesn't match the XHTML code in Listing 3.

Transform to CNXML

Later on, I used a Java program of my own design to transform the final XHTML document into anotherflavor of XML known as CNXML for publishing on the Connexions website.

That illustrates another characteristic of XML. Because the formats of certain flavors of XML documentsare well defined, it is often practical to transform them from one flavor to another flavor.

That makes it possible for me to create the document using a program that is very similar to a word processorand then transform the output of that program into a fairly cryptic format that satisfies the publishing requirements of the website.

Your browser is rendering the document

When you accessed the document from the Connexions website, it was transformed back into an XHTML document and sent to yourcomputer.

As you can see in Listing 3, viewing raw XHTML isn't very enjoyable. Fortunately, your browser isacting as a rendering engine to render the raw XHTML text into a much more pleasing presentation format.

Back to the book example

A book that is created and maintained as an XML document could be rendered in a variety of different ways. Whichever way it is rendered, however, it wouldprobably be useful to separate and number the chapters. Therefore, the value of the number attribute could be used by the rendering engine to present the chapter number for a specific rendering.

In some renderings, the number might appear on an otherwise blank page that begins a new chapter. In a different rendering, the chapter number might appearin the upper right or left-hand corner of each page.

Tell me again, what is an element?

As I explained earlier, an element usually consists of a start tag (with optional attributes and namespace information) , an end tag , and the content sandwiched in between as shown earlier in Listing 2.

Elements can be nested

Elements can be nested inside other elements as shown in Listing 4.

Listing 4 . Nested elements.
<book><chapter number="1">Content for Chapter 1</chapter><chapter number="2">Content for Chapter 2</chapter></book>

In Listing 4, two chapter elements are nested inside a book element.

Why does XML use elements?

It is probably fair to say that the element constitutes the fundamental unit of information in an XML document. For example, the element defines the type ofinformation, such as chapter in our book example.

Sandwiched in between the start tag and the end tag of an element, we find the raw information (content) that the XML document is designed to convey. For a text document, you are likely to find a lot of content between the tags. Forexample, in Listing 3, there are several lines of text between the paragraph tags identified by the p and the /p enclosed in angle brackets.

Once again, what is content?

Of the four terms mentioned earlier, (tags, elements, content, and attributes) , content is the easy one. Content is sandwiched in between the start tag and the end tag of an element. Usually the content of the elements containsthe information that the XML document is designed to convey. In other words, this is where we put the information for which the document was created. Thetags and attributes are there to create the structure.

For example, if the XML document is being used for the creation and maintenance of material for a newspaper, the content constitutes the news. Ifthe XML document is being used for the creation and maintenance of a Java programming textbook, the content contains the information about Javaprogramming that we want to convey to the student.

Why do we need structure?

One of the primary objectives of XML is to separate content from presentation. If we insert the raw material as content into a structure definedby the tags, elements, and attributes, then that raw material can be presented in a variety of ways.


This section contains a variety of miscellaneous materials.

Housekeeping material
  • Module name: XML - Tags, Elements, Content, and Attributes
  • File: FlexXhtml0082.htm
  • Revised: 12/02/14

Financial : Although the Connexions site makes it possible for you to download aPDF file for this module at no charge, and also makes it possiblefor you to purchase a pre-printed version of the PDF file, you should be aware that some of the HTML elements in this module maynot translate well into PDF.

I also want you to know that, I receive no financial compensation from the Connexions website even if you purchase the PDF version ofthe module.

In the past, unknown individuals have copied my modules from cnx.org, converted them to Kindle books, and placed them for sale onAmazon.com showing me as the author. I neither receive compensation for those sales nor do I know who does receive compensation. If youpurchase such a book, please be aware that it is a copy of a module that is freely available on cnx.org and that it was made andpublished without my prior knowledge.

Affiliation : I am a professor of Computer Information Technology at Austin Community College in Austin, TX.


Questions & Answers

how can chip be made from sand
Eke Reply
is this allso about nanoscale material
are nano particles real
Missy Reply
Hello, if I study Physics teacher in bachelor, can I study Nanotechnology in master?
Lale Reply
no can't
where is the latest information on a no technology how can I find it
where we get a research paper on Nano chemistry....?
Maira Reply
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
Application of nanotechnology in medicine
has a lot of application modern world
what is variations in raman spectra for nanomaterials
Jyoti Reply
ya I also want to know the raman spectra
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
yes that's correct
I think
Nasa has use it in the 60's, copper as water purification in the moon travel.
nanocopper obvius
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
analytical skills graphene is prepared to kill any type viruses .
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
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Source:  OpenStax, Introduction to xml. OpenStax CNX. Dec 02, 2014 Download for free at https://legacy.cnx.org/content/col11207/1.18
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