IBM WebSphere
software platform for
e-business
XML Review
Cao Xiao Qiang
Solution Enablement Center, IBM
May 19, 2001
Agenda
What is XML?
Why XML?
XML Technology
Types of XML Documents
DTD
XSL/XSLT
Available XML Tools from IBM
Competitive Perspectives
Summary
For More Information...
What is XML?
What is XML?
EXtensible Markup Language
New technology for web applications
Based on tags
User-defined tags identify the kind of data represented
Designed to easily represent data in a very portable manner
What is the key message of Java?
Code portability (i.e. Write Once, Run Anywhere)
What is the key message of XML?
Data portability
What is XML?
XML and Java technology
are the "yin and yang of
cross-platform computing"
-- Jon Bosak
"Father of XML"
Rob
Roy
1000
1000.25
What is XML?
XML tags are user defined
Can be enforced by rules (covered later)
Buffalo Wings
Sirloin Steak>
Peas
Ice Cream
Why XML?
XML provides a standard way of exchanging
data:
Business-to-Business (B2B)
B2B revenue $109 billion in 1999
B2B revenue $2.7 trillion by 2004 (Forrester)
How would B2B data exchange without XML?
EDI, TextFiles, PDF, proprietary messages?
XML certainly has applicability in non-B2B
environments as well
Bottom Line: XML simplifies B2B transactions
the web
What's wrong with just HTML?
HTML simply defines how something should be rendered
Does not define what the data is
Customer List
Customer: Rob Roy
Account # 1000
Balance: 1000.25
CustList.html
Why XML
Rob
Roy
1000
1000.25
CustList.xml
XML defines the data
Rendering can easily be applied to XML using Style Sheets
(XSL) (covered later)
Customer
List
Customer: Rob Ro
Account # 1000
Balance:
1000.25
CustList.html
Customer: Rob
Roy
Account # 1000
Balance:
1000.25
CustList.WML
Customer Rob Roy
Account List
Account # 1000
Acct Balance:
1000.25
CustList.doc
Key Benefits of XML
Vendor and Platform Independence
Easily model data at any level of complexity
Extremely Extensible
Define new tags as needed
Easily validate data to check for structural correctness
Media independence to publish content in multiple
formats:
e.g. HTML, WML, CompactHTML, etc.
Practical Uses for XML
B2B Communication
Company A wants to exchange information with
Company B
Company A doesn't need to understand how Company
B organizes their data
Company A simply follows some simple rules when
sending the data
These rules are defined in a DTD (covered later)
Smart Searches
Search Engines can't process HTML intelligently
e.g.: Search for Rock
Results: Rock Bands, Rock Candy, Rock the movie,
etc.
XML addresses data content
XML Technology
Anatomy of an XML Document
Rob
Roy
1000
1000.25
XML Comment
XML Prolog XML Element
XML Attribute
Legend
What are DTDs?
Document Type Definition
"Schema" definition for XML documents
Defines the structure of an XML document
Defines what tags can go in an XML document
Defines what tags can contain other flags
XML References DTD in XML prolog
...
CustList.xml
Anatomy of a DTD
DTD Symbols:
Symbol Meaning Example
ELEMENT Declaration of Element
ATTLIST Attribute List for an element
| OR operator
? Element is optional
+ Must be 1 or more elements
* Must be 0 or more elements
#PCDATA String Data
CustList.DTD
The OBCustomerList element contains 0 or more
customer elements
Anatomy of a DTD
CustList.DTD
The customer element contains:
1 cust-id element
1 cust-fname element
1 cust-lname element
1 cust-addr element
0 or 1 cust-email elements
0 or more account elements
Three Types of XML Documents
Well-formed Documents
Documents which follow the XML tag rules, but don't have
a DTD
Invalid Documents
Documents which doesn't follow the rules defined in its
DTD
Documents which are incorrect syntactically
Invalid:
Valid:
Valid Documents
Documents which follow the rules defined in their DTD
Interpreting (Parsing) XML Documents
XML Parsing is the mechanism used to interpret the
content of an XML document
Two Approaches to Parsing XML documents
Document Object Model (DOM)
Simple API for XML (SAX)
DOM is a standard of the World Wide Web Consortium
(W3C)
SAX is the "de-facto" standard for parsing XML
documents
DOM Parsing
DOM creates a tree view of your XML document
Recursion is used to navigate the tree
SAX Parsing
SAX is event driven
Events are sent as the
XML document is
parsed
e.g. StartDocument,
StartElement,
EndElement,
characters, etc.
Application program
determines what
elements are important
SAX vs. DOM
DOM has richer set of functions for interpreting content
in XML document than SAX
DOM should be used when you need to know a lot about
the structure of a document
In-memory tree constructed of XML document
SAX has a simpler programming model
Event driven (SAX) vs. recursion (DOM)
SAX uses less memory than DOM
SAX doesn't constuct the XML document in-memory
SAX vs. DOM
Use DOM when:
You need to use the information in an XML document
more than once
DOM creates an in-memory tree which you can
navigate many times while only parsing the XML
document once
You need to know a lot about the structure of a
document
e.g. Relationships between elements
Use SAX when:
You need to parse/navigate XML document once
You need only a few elements in XML document
Small memory requirements
XSL
XSL is a transformation and formatting language
An XSL stylesheet is used to transform XML into another
format
e.g. HTML, XML, etc
XSL stylesheets contain templates that define how the
XML elements should be transformed
XSL Example
Customer Found:
CustList.XSL
XML Element
Template Rule}
XSL Transformation
Where can the transformation happen?
Client Side (with XML/XSL capable browser):
XML document and style sheet are served to client
Microsoft Internet Explorer 5.0 support this
Server Side:
Server applies XSL style sheet to XML document and
sends the transformed document to the client
WebSphere with LotusXSL
AlphaWorks XML Enabler
A "third" program performs transformation and places
transformed document on server
XT or Microsoft msxsl tool
Server Side transformation are usually best
XML Tools from IBM
XML Tools from IBM
IBM XML Parser for Java
Industry leading DOM/SAX XML parser
LotusXSL
Server-side XSL processor
Available in WebSphere or AlphaWorks
XML Enabler
Uses LotusXSL to implement server-side XSL
processing
Visual XML Tools
Visual DTD
Visual XML Creation
Visual XML Transformation
Visual XML Query
XML Tools from IBM (continued)
Xeena
Visual XML authoring tool
XML Viewer
View XML/DTD from a single window
XML Generator
Generate XML test cases from a DTD
XML Security Suite
Digital Signature, element-wise encryption
XSL Editor
Visually edit/test XSL stylesheets
Alphaworks contains 40+ XML tools/solutions
What does VisualAge for Java Support?
Everything we've covered!
VisualAge for Java 3.5 ships with:
IBM XML Parser for Java
IBM XML Generator
Import LotusXSL to test/build XSL based solutions
Many of the AlphaWorks Java based tools can be
imported into VisualAge for Java as well
Launch External XML tools from Resources Page
IBM XML Tooling: Usage Scenario
Develop DTD
Primary Tool
IBM Visual XML Tools
Develop backend XML
application
Primary Tools
IBM VisualAge for Java
IBM XML Parser for Java
Generate XML Test
Cases
Primary Tools
IBM VisualAge for Java
IBM XML Generator
Unit Test XML
Application
Primary Tools
IBM VisualAge for Java
WebSphere Tes t Env .
Build XML
Primary Tools
IBM Xeena
IBM Visual XML Tools
Build XSL
Primary Tools
IBM XSL Editor
IBM Visual XML Tools
Deploy XML
Application
Primary Tools
IBM WebSphere Studio
IBM WebSphere AS
Competitive Perspectives
Competitive Perspectives
Microsoft making major investments in XML
Have XML, XSL, DTD solutions today
XML Software Development Kit (SDK)
XML support in (or coming):
Windows 2000
Windows DNA 2000
Microsoft BizTalk Server 2000 (may slip to 2001)
aka Microsoft XML Server
Microsoft SQL Server 7.0
Microsoft Office 2000
SOAP
.NET framework
I B M a n d M i c r o s o f t a r e t h e t w o
X M L l e a d e r s i n i n d u s t r y
Competitive Perspectives
IBM XML technology based primarily on Java
XML and Java offer great portability and openness
Microsoft technology not Java based
Linking XML technology with their product solutions
Summary
Summary - IBM and XML
IBM provides the most comprehensive XML solution in
industry:
Some key products enabled for XML:
WebSphere http://www-4.ibm.com/software/webservers/appserv
MQSeries
http://www2.itworld.com/cma/ett_article_frame/0,2848,1_245,00.html
DB2 UDB 7.1
http://www-4.ibm.com/software/data/db2/udb/pdfs/whatsnew.pdf
Industry leader in quality XML development tools
Why are they free from AlphaWorks? Leadership!
Tools are consistently ranked
very high by users
Microsoft XML tools in SDK include an xml parser, xsl
parser, and code examples
non-productive tools
Summary
XML is changing How companies manage/exchange data
In an open and portable manner
B2B data exchange will be a major factor in driving XML
The ultimate success of XML outside of high-end
applications may depend on easy-to-use tooling:
"XML is today where PostScript was before Adobe
Illustrator"
http://www.zdnet.com/zdnn/stories/comment/0,5859,2594206,00.html
IBM is positioned to be the leader in XML technology
For More Information...
For More Information...
http://www.ibm.com/xml
Links to all things XML
http://pdbeam.uwaterloo.ca
Several XML Tutorials
http://www.javaworld.com
Several articles on programming XML in Java
http://www.alphaworks.ibm.com
Many XML Tools
XML and Java - Developing Web Applications
Hiroshi Maruyama, Kent Tamura, Naohiko Uramoto
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