XML Configuration File

hello, Family , Today we are going to study XML The configuration file

Catalog

One . What is? XML？

Two .XML The role of

3、 ... and . Why should we use XML？

Four .XML Structure diagram

5、 ... and . The standard XML Format

6、 ... and .🥤🥤 Element definition

7、 ... and . Attribute definitions

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One . What is? XML？

XML Designed to transmit and store data ,XML Extensible markup language .

• XML Extensible markup language （EXtensible Markup Language）.
• XML It's like HTML The markup language of .
• XML The purpose of the design is to transmit data , Instead of showing the data .
• XML The label is not predefined . You need to define your own tags .
• XML Designed to be self-descriptive .
• XML yes W3C The recommended standard of

If you don't understand XML Right again XML If you are interested , You can click this link to see ：XML brief introduction – What is? XML？ | Novice tutorial XML brief introduction XML Designed to transmit and store data . HTML Designed to display data . XML Extensible markup language （eXtensible Markup Language）. Extensible markup language （ English ：Extensible Markup Language, abbreviation ：XML） It's a markup language , From standard General Markup Language （SGML） Simplified and modified from . It mainly uses extensible markup language 、 Extensible style language （XSL）、XBRL and XPath etc. . The basic knowledge that should be mastered As you continue to learn ..https://www.runoob.com/xml/xml-intro.html

Two .XML The role of

XML be applied to Web Many aspects of development , It is often used to simplify the storage and sharing of data

• XML The data from HTML Separate
• XML Simplify data sharing
• XML Simplify data transfer
• XML Simplify platform changes
• XML Make your data more useful
• XML For creating new internet languages

3、 ... and . Why should we use XML？

xml The ability to run between different system platforms and convert into different format object files makes it an excellent choice in content management application systems

Four .XML Structure diagram

 

5、 ... and . The standard XML Format

• There is and only one root element
• XML Labels are case sensitive
• Use the end tag correctly
• Nesting labels correctly
• Legal tag name used
• Define valid properties

6、 ... and .🥤🥤 Element definition

• The classification of elements

 

1. Empty elements

<!ELEMENT element-name EMPTY> // Empty elements 

2. Text elements

<!ELEMENT element-name (#PCDATA)>// Text elements 

3. Mixed elements

<!ELEMENT element-name(e1,e2)> // Mixed elements 

• The limitation of elements

And (,)                  Not (|)

Times are divided into ：

0 or 1	use ？ The sign means
0~N	use * The sign means
1~N	use + The sign means

• Case study

 

7、 ... and . Attribute definitions

grammar ：

<!ATTLIST element-name att_name type desc>

• Attribute types type

1. ID： To write elements, you must write this
2. ( male | Woman ) ： Only male or female
3. CDATA： Text attribute
4. IDREF： Quote someone else ID The value in
5. reference（ To use less ）
    

• Property description

#REQUIRED： Required

#IMPLIED： Not required

' The default value is '

Be careful ： Only type by ( male | Woman ) Type ,desc Can use the default value

• Case study

 

 

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