The first line of an XML page starts with:

<Code
  language="xml"
  text={`<?xml version="1.0" encoding="ISO-8859-1"?>`}
/>

This lets the viewing browser know what type of coding and what language character set is being used. ISO-8859-1 happens to be the Latin-1/West European set which is the most common.

<Code
  language="xml"
  text={`<?xml version="1.0" encoding="ISO-8859-1"?>
   <list_of_movies>
      <movie>
         <title> Finding Nemo </title>
         <age_group> Kids </age_group>
         <comments> Fish are friends, not food. </comments>
      </movie>

      <movie>
         <title> Monty Python Holy Grail </title>
         <age_group> Adult </age_group>
         <comments> A shrubbery for the Knights who say Nee! </comments>
      </movie>

      <movie>
         <title> Harry Potter </title>
         <age_group> All </age_group>
         <comments> Very popular for all ages. </comments>
      </movie>
</list_of_movies>`}
/>

Take a look at how you can build a webpage using XML.

My First XML Page

All these letters, abbreviations, meanings and so forth. What do they all mean and how do we use them? Here are some basics breakdown :

First we will start at the top. The VERY top. **SGML** stands for **S**tandard **G**eneralized **M**arkup **L**anguage. Simply put, it is the very root coding of coding. HTML is an application of SGML.

**XML** is a simplified subset of SGML. It stands for eXtensible Markup Language.

**DTD** stands for Document Type Declaration. It is a set of instructions that states what tags are usable and what (re)action they create. Each browser has a DTD set in it's programming set by the browser companies. This is how some tags will work in only one type of browser or version. It has the tags stated in it's DTD. XML makes it possible to create unique tag sets by applying it's own DTD. This makes the DTD more compatible with more browsers.

**XSLT** stands for eXtensible Stylesheet Language Transformation. It is a strong versions of CSS that formats the XML page for viewing.

Learn what XML, DTD, and XSLT are and how they can be used.

What is XML, DTD, and XSLT

Depending on who is teaching, different terms mean the same things...

The term **elements** means the tags.

The term **attributes** means properties.

<Code
  language="xml"
  text={`<tag property="value">`}
/>

Part of the previous example of XML looks like this:

<Code
  language="xml"
  text={`<movie>
      <title> Finding Nemo </title>
      <age_group> Kids </age_group>
      <comments> Fish are friends, not food. </comments>
</movie>`}
/>

Each piece of information is in its own element (tag). The child elements (nested tags) may be shown as attributes (properties) instead of elements. Here is the same example switching the TITLE tag into a property instead of being a full tag on its own...

<Code
  language="xml"
  text={`<movie title="Finding Nemo">
      <age_group> Kids </age_group>
      <comments> Fish are friends, not food. </comments>
</movie>`}
/>

The same effect can be done for any of the other child elements as well...

<Code
  language="xml"
  text={`<movie title="Finding Nemo" age_group="Kids" comments="Fish are friends, not food">
</movie>`}
/>

Technically, both styles of coding are correct. Having items as properties instead of tags though kinda defeats the purpose of modular XML processing.

Learn about how and why you'd use elements and attributes when working in XML.

Elements and Attributes

Normal CSS stylesheets may be used to control the display formatting of the information in an XML document. Here is a very simplified style sheet to use on our example...

<Code
  language="xml"
  text={`title, age_group ,comments {display:block;}
title {font-size:14px; color:#f00; text-decoration:underline;}`}
/>

The first line will make the contents of each element display in block formation. (it will take up the full line and put the next bit of information on the next full line).

The second line will format the information found within the **title** tags.

Saving that snippit as "example.css" we can then attach it to the XML example coding...

<Code
  language="xml"
  text={`<?xml version="1.0" encoding="ISO-8859-1"?>
<?xml-stylesheet type="text/css" href="example.css"?>
   <list_of_movies>
      <movie>
         <title> Finding Nemo </title>
         <age_group> Kids </age_group>
         <comments> Fish are friends, not food. </comments>
      </movie>

      <movie>
         <title> Monty Python Holy Grail </title>
         <age_group> Adult </age_group>
         <comments> A shrubbery for the Knights who say Nee! </comments>
      </movie>

      <movie>
         <title> Harry Potter </title>
         <age_group> All </age_group>
         <comments> Very popular for all ages. </comments>
      </movie>
</list_of_movies>`}
/>

Now that there is some formatting applied to the XML page, it will actually display the data only instead of all of the raw tags.

This example wont win any great awards, but it does its job by showing the example in action :)

XSL and XSLT is used to format an XML document correctly. CSS is good for HTML coding, but XSL will take our XML document to a much higher level of formatting.

Learn about how XSLT is used to style XML.

Styling XML

**XML**
- XML stands for eXtensible Markup Language.
- XML is similar to HTML.
- XML tags are not pre-defined. You create and define them using DTD.
- XML documents are saved as text files with the **.xml** extension.
The main difference between HTML and XML is action. XML will describe data, HTML will display data. XML will structure, store and send data information.

HTML uses a set of pre-defined tags. \<p\> \<div\> \<br\> and so forth. XML allows you to define and use your own tags.

<Code
  language="xml"
  text={`<my_code>
   <tag1>
      data information here
      <tag2>
         data information here
      </tag2>
   </tag1>
   <tag3>
      data information here
   </tag3>
</my_code>`}
/>

The tag names may be almost any word you can think of. It can be a combination of letters, numbers, and underscores. It should be descriptive to make it easy for you to understand what the area is. It cannot start with the letters XML and must start with a letter or underscore.

XML Syntax:
- There must be a "root" or main tag set surrounding all others.
- Correct nesting of tags is essential. No overlapping.
- CaPiTaLiZaTiOn is important.
- Property values must be "quoted"
- Ending of tags is required.
- XML comments are the same as HTML comments. \<!-- text --\>

XML

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