xml – an introduction
DESCRIPTION
XML – An Introduction. What Is XML?. Extensible markup language Encoding objects based on their structure and meaning of content Convergence of three technologies: Document markup Data interchange World wide web. Why XML?. To address HTML limitations - PowerPoint PPT PresentationTRANSCRIPT
XML – An Introduction
What Is XML?
• Extensible markup language
• Encoding objects based on their structure and meaning of content
• Convergence of three technologies:– Document markup– Data interchange– World wide web
Why XML?
• To address HTML limitations
• Enabling technology for a business web
• Next generation web
Basic XML Process
XML Document
Application Specification
Object
Processing
Engine
Content, structure, meaning
What to do with XML
End Result
Processing XML
• Parsers• Parsers are commodity items• Two basic types:
– Tree based (DOM)– Event based (SAX)
• Your applications requirements decide which one to use
• Validating parsers
XML Validity
• Well-formed is not always enough.
• Provides higher level conformance.
• Include formal definition of data model.– Document type definition (DTD).– Schema.
• A DTD defines a document type.
XSL and XSLT
• XSL– XSLT – transformation stylesheet– XSL FO – formatting objects
• XSLTXML Document
XSLT Style sheet
XSLT Engine HTML Document
Very Simple Example
<person type=“fictional”>
<name>
<first>Peter</first>
<last>Pan</last>
<feature>flies</feature>
</person>
XSLT Engine
<xsl:stylesheet version=“1.0”>
<xsl:template match=“person”>
<html><p>
<xsl:apply-templates/>
</p></html>
</xsl:template>
</xsl:stylesheet>
<html><p>PeterPanflies</p></html>
XML Future
• Http & XML =.– Soap.– XML-RPC.– Can work across firewalls.– Platform independent.
• XML enabled data bases.• XML enabled search engines.• Industry standard XML vocabularies.