XML Tutorials - Herong's Tutorial Examples - v5.25, by Herong Yang
Types of Information in XML Files
This section describes 6 types of information in an XML file: Processing Instruction, Comment, XML Element, Mixed Text, XML Entity, and CDATA Section.
There are 6 types of information in an XML file:
1. Processing Instruction: Used to pass an instruction to applications that processing this file. Processing instructions are written in the following syntax:
<?target instruction?>
where "target" is the name of a target group of applications expected to use this instruction, and "instruction" is the actual instruction to be passed to those applications.
2. Comments: Used only to comment the XML file. Comments will be ignored by application that processing this file. Comments are written in the following syntax:
<!--comment-->
where "comment" is the text of comment.
3. XML Elements: Used to present a unit of information, with a name, an optional body, and optional attributes. Elements are written in the following syntaxes:
<tag/> <tag attributes/> <tag>content</tag> <tag attributes>content</tag>
where "tag" is the name of the element, "content" is a string of text, or text mixed with XML elements, and "attributes" is a pair of name and value or a list of multiple pairs of name and value written in the following syntax:
name="value" name_1="value 1" name_2="value 2" ... name_n="value n"
4. Mixed Text: A string of text, or text mixed with XML elements, used as contents of elements. Examples of mixed text:
This mixed text only contains characters. This mixed text <br/>contains characters and <b s="1">elements</b>. This mixed text contains entities, &, <</b>.
5. XML Entities: Special escape sequences to represent XML reserved characters. XML entities can be used in element content and attribute values. These are XML pre-defined entities and reserved characters they are representing:
Entity Character & & ' ' > > < < "e; "
5. CDATA Section: A section of text in which any XML reserved characters should be treated as normal characters. CDATA sections are written in the following syntax:
<![CDATA[ text line ... ]]>
Table of Contents
Introduction of XML (eXtensible Markup Language)
►Types of Information in XML Files
The <?xml ...?> Processing Instruction
dictionary.xml - A Simple XML Sample File
DOM (Document Object Model) Programming Interface
SAX (Simple API for XML) Programming Interface
DTD (Document Type Definition) Introduction
Validating an XML Document against the Specified DTD Document Type
XSD (XML Schema Definition) Introduction
Validating XML Documents Against Specified XML Schemas
XSL (Extensible Stylesheet Language) Introduction
XSLT (XSL Transformations) Introduction
XSLT Elements as Programming Statements
Control and Generate XML Element in the Result
PHP Extensions for XML Manipulation
Processing XML with Python Scripts
XML Tools Plugin for Notepad++
XML Plugin Packages for Atom Editor