Explore XML

Explore XML

1. XML is a software- and hardware-independent tool for storing and transporting data.

   • XML Does Not Use Predefined Tags

2. XML Tree

   1. Root Element (Parent)

   2. Element (Child) - Attribute

        * Element (Sibling) 

   3. Text

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

   

3. Self-Describing Syntax

4. XML Syntax Rules

   1. XML Documents Must Have a Root Element

   2. The XML Prolog

        * <?xml version="1.0" encoding="UTF-8"?> 

   3. All XML Elements Must Have a Closing Tag

   4. XML Tags are Case Sensitive

   5. XML Elements Must be Properly Nested

   6. XML Attribute Values Must be Quoted

   7. White-space is Preserved in XML

5. XML Element - An element can contain:

   1. text

   2. attributes

   3. other elements

   4. a mix of the above

   5. Empty elements can have attributes.

6. XML Naming Rules

   1. Element names are case-sensitive

   2. Element names must start with a letter or underscore

   3. Element names cannot start with the letters xml (or XML, or Xml, etc)

   4. Element names can contain letters, digits, hyphens, underscores, and periods

   5. Element names cannot contain spaces

7. XML Namespaces - XML Namespaces provide a method to avoid element name conflicts.

8. XPath Path Expressions - XPath uses path expressions to select nodes or node-sets in an XML document. These path expressions look very much like the expressions you see when you work with a traditional computer file system.

9. XSLT (eXtensible Stylesheet Language Transformations) is the recommended style sheet language for XML. - With XSLT you can transform an XML document into HTML.

10. XQuery is About Querying XML - XQuery is a language for finding and extracting elements and attributes from XML documents.