One, XML related definition
1,html is just a static document and cannot adapt to requirements. A set of specifications created by the Internet Consortium for XML, for software developers and content creators to organize information on Web pages, not only to meet the growing demand for network applications, but also to ensure good reliability and operability when interacting over the network. XML originates from SGML (Standard generalize Markup Language), which preserves the functionality of the sgml80% and reduces the complexity by 20%. It has the scalability and flexibility that HTML does not have. It is actually a definition language, that is, the consumer can define endless tags to describe any data elements in the file, thus breaking through the constraints of the HTML fixed tag set, making the file content richer and more complex and form a complete information system.
2,xml has 3 main elements: schema (Schema), XSL (Extensiblestylesheetlanguage), and XLL (Extensiblelinklanguage). Schemas define the logical structure of the XML file, defines the relationships between the elements in the XML file, the attributes of the elements, and the attributes of elements and elements, and it helps the XML Analyzer validate the validity of the XML file. XSL is the language used to specify the style of the XML document, which enables the Web browser to change the presentation of the document on the client. There is no need to communicate with the server again. XLL will further expand the existing simple links on the web.
3,xml provides a rule for making labels. Under this rule we produce a DTD (document Type Definition) file for browsers and readers to read. It is a markup language that describes the main semantics of a file structure. XML describes the structure and meaning of the file rather than the appearance (completed by style sheet).
Advantages of 4,xml
1 Define the markup language for the professional domain.
2 The General Data format (text format).
3 Easy for data exchange
4 structured data. You can specify the relationships between elements. It also provides a special mechanism for merging data from multiple sources and then displaying it as a single file. Can also be based on the user's action to determine the partial data display or hidden.
XSL, itself an XML file, is a style sheet specifically designed for XML that describes how XML appears. XLL is the link syntax for XML. including xlinks,xpointers
5,xml Standard specification.
Statement: XML version= "1.0" standalone= "yes"?> cannot have spaces or other characters before. Standalone refers to whether there is a matching DTD file.
<!----> Intermediate notes
When we start with XML and tag manage, we call it well-formed XML.
Second, XML syntax
1, the statement recommended to join. One of the processing instructions. Version is required and standalone,encoding (GB2312,BIG5,UTF8) is optional. If the label is written in Chinese, it must be GB2312
2, Element <tag>value</tag> a file has at least one root element (also known as a file tag).
Special characters in value (<>&.) Must be replaced with its entity reference.
There should be at least one tag in an XML file.
Case sensitive. The start and end tags must correspond strictly. If the unmarked body can use <tab param=value .../> says
Tag names can begin with an alphanumeric underline or a colon (not recommended). followed by an alphanumeric period colon underline or hyphen--but no spaces in the middle, and no tags can start with XML.
There are no restrictions on the number of attributes in the tag. The length of the tag name is theoretically unrestricted.
The property value must be enclosed in double quotes.
4,<! [cdata[* * * * *]]> the * * * * can be any character other than]]>.
<!--comment--> comment cannot appear-,--, >, nor can it be nested.
Third, the JSP XML syntax
<% @page param=value%> <jsp:derective.page param=value/>
<% @include file= "F"%> <jsp:derective.include file= "F"/>
The action element is originally an XML format and only needs to convert the traditional format of value= "<%=expression%>" to an XML-formatted value= "%=expression%" (used in standard or custom tags) when using the request time attribute.