Repurpose Your Data! XSL Transformations in e-business solutions

Transcription

1 Repurpose Your Data! XSL Transformations in e-business solutions XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 1 Mark Colan e-business vangelist IBM Corporation mcolan@us.ibm.com ibm.com/developerworks/speakers/colan

2 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 2 Agenda This is an Overview to the use of XSLT, XPath, and XSL Formatting Objects Why do we need XSL Transformations? What is XSL? XSL in Application Architectures Tools for XSL Programming Q & A Solutions sessions on XSL and XSLT Tues, 3:30-5:45 Weds, 11:45-12:45 XSL by Example: An Introduction to XML Transformations (Colan) Transforming XML Documents with XSLT (Tidwell)

3 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 3 Part 1: Why do we need XSL Transformations? "A typical enterprise will devote 35-40% of its programming budget to develop and maintain 'extract and update' programs whose purpose is solely to transfer information between different database's of legacy systems." --Gartner Group

4 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 4 XML is about REPURPOSING data Data is expensive to enter, validate, update Data is a valueable asset! XML data is easy to repurpose and reuse...using standard tools for transformation XSL allows XML data to be restructured, restyled, or converted to another form: XML to HTML XML to XML (vocabulary translation) XML to Formatting Objects XML to non-xml (e.g. comma-separated files)

5 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 5 Alternatives to XSL XML Parser + Java DOM code infinitely flexible LOTS of code to develop and maintain does not address problem cited by Gartner Group statement PERL 5 + XML4P DOM access in a Perl environment suitable for server deployment XML4P available at xml.apache.org less code than Java, but more than XSL

6 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 6 <term>vocabulary</term> A definition of the names in the tags the arrangement of the tags (structure) the types, default values, valid values Written as: Old way: DTD (Document Type Definition) Better: XML Schema (adds type support) Industry-specific vocabularies are developed by cooperating companies, then registered at XML.ORG to become standard.

7 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 7 The XML.org catalog That's it for the letter "A"... as of Jan 2000, there are over 110 vocabularies in the catalog!

8 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 8 The Tower of Babel problem... Does the growing number of vocabularies represent a fragmentation which will subvert the goals of XML? Can I add my own tags to one of these vocabularies and still exchange data with others in my industry? My business processes are built on a model that is not well supported by the industrystandard vocabulary, so we wrote our own. How can we exchange data with others? What about a new version of a vocabulary?

9 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 9 Part 2 What is XSL? extensible Stylesheet Language is set of specifications from the W3C a language for stylesheets and transformations a presentation-oriented vocabulary An XSL processor is software that transforms and styles XML data, either at the client or on the server

10 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 10 XSL: Three parts XSL XSLT Formatting XPath Objects Transformation language a language for addressing parts of an XML document an XML Vocabulary for specifying formatting semantics

11 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 11 XSL Processing Overview Source XML document (data to be transformed) Apache Xalan, LotusXSL,... Source XML XSL Style Sheet XSLT Engine Result Tree app processing Result XML Stream one or more templates in the XSL syntax

12 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 12 XSLT: A Simple Example Problem: Display the title (only) in html as <h1> headline <book> <author>tom Wolfe</author> <title>the Right Stuff</title> <price>$6.00</price> </book> XML Input File: Book0.xml XSL PROCESSOR <xsl:stylesheet> <xsl:template match="title"> <h1> <xsl:apply-templates/> </h1> </xsl:template> </xsl:stylesheet> XSL Style Sheet Input File: Book0.xsl <h1> The Right Stuff </h1> HTML Output Book0.xml Book0.xsl

13 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 13 XSLT Features Multiple input files and output files using extension Named and pattern-based templates Declaration of variables and parameters Combined stylesheets Selecting Sorting Numbering Serialization control, including to non-xml Extension mechanism

14 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 14 XSLT is not intended to be a general-purpose programming language! Variables cannot be reassigned No counters or counted for-loop Best for reducing structure <Firstname> <Lastname> <FullName> <FullName> <Lastname> <Firstname> Extension can add needed logic for above These limitations allow XSLT to be optimizable and incremental.

15 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 15 What is XPath? a language for addressing parts of an XML doc represented as tree of DOM nodes separate specification: designed to be used by XSLT, XPointer, simple queries,... compact, non-xml syntax, can be used in URI's and XML attributes has a natural subset that can be used for pattern matching in XSLT

16 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 16 Why is it called XPath? Expressions describe a path to a given node or set of nodes Consider the DOS, Unix, or URI syntax for addressing files in a directory structure /publications/articles/transformations.xml this is called a pathname to the file it describes the path to follow, from the "root", thru a tree of directories (folders), to locate a given file XPath also uses a forward slash to separate components (nodes) of a path

17 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 17 XPath Features URL-like path selection Axis traversal semantics Predicates Basic data types: number, boolean, string, node-set Path expressions Math, string, boolean expressions Access by index Namespaces Variable use (but not declaration) Extension mechanism

18 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 18 XPath Examples title matches all <title> nodes /book/chapter/title matches all <title>s that are children of <chapter>s that are children of the <book> child::title and./title selects all <title>s that are children of the context node title[1] and title[last()] select first and last <title>s that are children of the context node /book/chapter[position() mod 2 = 0]/title matches <title>s of even-numbered <chapters>s speaker[firstname="mark"] matches <speaker>s whose first name is Mark

19 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 19 Formatting Objects A presentation-oriented vocabulary typically generated by XSLT Spec is "candidate recommendation": not yet "frozen" A Formatting Objects processor can render XSL FO result into PDF, HTML, or other forms Apache FOP translates a Formating Objects stream to PDF beta available at xml.apache.org

20 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 20 International Considerations The FO model has two layout types: inline: e.g. text arranged in lines blocks: groups of lines (e.g. paragraphs), pictures, title areas,... XSL FOs support any direction for blocks and inline text to accomodate all languages: left-to-right right-to-left top-to-bottom bottom-to-top

21 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 21 Summing up XSL Programming XSLT is a language for transformations looks for matches to a template changes data "by example" XPath specifies desired nodes works like a pathname of a file can be used to describe a query Formatting Objects define presentation can render international languages

22 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 22 Part 3: XSL in Application Architectures

23 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 23 XSL Processing Overview Source XML document (data to be transformed) Apache Xalan, LotusXSL,... Source XML XSL Style Sheet XSLT Engine Result Tree app processing Result XML Stream one or more templates in the XSL syntax

24 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 24 XSL is at home on the Client... HTML Stream XSL XML Stream Style Sheet query Client Server

25 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 25...and at work on the Server DB2 XML Extender HTML Stream XSL SQL Translator SQL Style Sheet Client IBM Websphere, Lotus Domino, Apache, etc Middle-tier Server DB2 Universal Database Legacy Data Store

26 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 26 Portals SAP The Web? XSL Server Legacy Data Store

27 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 27 Transcoding Hey! Traditional Print Media Hey! PDF Files Fax back XSL FOP Web content Hey! Hey! Handhelds 4 HEY! VoiceML Content Creation Transcoding Server ebook content

28 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 28 SABRE/Nokia Architecture using WebSphere Transcoding Publisher

29 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 29 Business-to-Business Company A External XSL External XSL Company B XSL at external server: internal to standard vocabulary transformation

30 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 30 Application Integration Manufacturer Parts Supplier Procurement Catalog Manager XSL XSL ERP: Pricing & Availability Product Info Management Departments function as separate entities Vocabularies may need XSL transformation for integration with catalog producer

31 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 31 SOAP Message Transformation Parse and SOAP Dispatch Incoming Message Parsed Message XSLT Message Handler Transformed Message

32 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 32 Layered Web Services Company A Virtual Company XSL Company B Virtual Company Company C XSL

33 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 33 Part 4: Tools and Resources: XSL Programming

34 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 34 xml.apache.org Xalan - XSL Processor Xalan-J: Java version 2.1 Xalan-C: C++ version 1.1 IBM also contributed: Xerces XML Parser, for Java and C++ XML4P (Xerces with Perl5 bindings) SOAP4J, first portable implementation of SOAP 1.1 specification.

35 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 35 Xalan 2.x for Java Available on xml.apache.org Version 2.1 released May, 2001 Xalan 2.2 D7 (developer release) released July, 2001 Features: Major performance enhancements over Xalan 1.0 TrAX/JAXP API Runs with Xerces Xalan 1.0 compatibility layer Xalan 2.2 features Document Table Model internal structures Version 2.1 is solid, stable: recommended for use in your products (rather than Xalan 1.x versions)

36 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 36 Xalan 1.x for C++ Xalan 1.1 released Feb 20, 2001 works with Xerces/C 1.4 grealy improved performance improved spec conformance new platforms: HP-UX and Solaris in addition to AIX, Linux, Win32 since 1.0 more samples many bug fixes

37 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 37 Other XSL Processors XT (by James Clark, now fading away) SAXON (from Michael Kay, author of XSLT Programmer's Reference) XSLTC stylesheet compiler from Apache IE5 (Microsoft) Oracle XML Dev Kit (Java, C++) ixslt (infoteria, C++) EZ/X (Activated Intelligence, Java) XML::XSLT (Geert Josten, Perl) XPort (TIMELUX, C++ COM Object)

38 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 38 Formatting Objects Processors Apache: FOP version 0.19 create a PDF from XSL:FO document supports XSL Candidate Recommendation 11/2000 not yet a full implementation Antenna House - FO to PDF (commercial) RenderX - FO to PDF (commercial)

39 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 39 XSL Resources from IBM ibm.com/alphaworks XML processors, tools, editors, diff tools XSLT processor, editor, trace ibm.com/developerworks/xml articles, tutorials, source code several tutorials on XSL www6.software.ibm.com/reg/xml/transformxml-i ibm.com/developerworks/speakers/colan XSL by Example presentation, companion files other presentations on XML and Web Services XSL by Example Tuesday 3:30-5:45pm

40 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 40 XSL Tools on Alphaworks ibm.com/alphaworks LotusXSL - Apache Xalan wrapped with Domino, DB2, generic db access features the older LotusXSL API XSL Editor (version 2.0 posted 1/13/00) XSL Trace Visual Transformation many other XML tools, software aids, etc XML Master (XMas) - generate custom Beans for working with a particular XML document from DTD VoiceXML - industry-defined voice markup language

41 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 41 XSL Editor 2.0 XML Source Stream XSL Templates...step and trace XML Result Stream

42 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 42 XSLT Resources W3C Specifications (XSL, XSLT, XPath) XSLT Programmer's Reference, Michael Kay, WROX Press XSLT in a Nutshell, Doug Tidwell, O'Reilly (coming August 2001) XSL Companion, Neil Bradley, Addison-Wesley Chapter 14 of XML Bible, Elliotte Rusty Harold, IDG Books, also available on web at metalab.unc.edu/xml/books/bible/updates/14.html Practical Transformation Using XSLT and XPath training materials, Ken Holman, Crane Softwrights Ltd (mailing list for general XSL questions) - various XSL-specific references

43 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 43 XSL Formatting Objects resources W3C Specifications (XSL, XSLT, XPath) Chapter 15 of XML Bible by Elliotte Rusty Harold IDG Books, July 1999, also available on web at: Formatting Object Processors (FO to PDF) open source: Apache FOP product: Antenna House product: RenderX

44 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 44 XSLT in IBM Products Xalan XSLT is integrated into Websphere Application Server proven, best-selling general-purpose middleware server ibm.com/websphere Lotus Domino Server middleware server with , shareable databases and several application design models lotus.com Websphere Transcoding Publisher server-side, easy-to-use solution for bridging data across multiple formats, markup languages and devices especially suitable for pervasive computing ibm.com/software/webservers/transcoding/

45 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 45 Websphere Transcoding Publisher ibm.com/software/webservers/transcoding/ server-side, easy-to-use solution for bridging data across multiple formats, markup languages and devices adapts, reformats, and filters content to make it suited for pervasive computing on a variety of devices conversion options: HTML to simplified HTML HTML to Wireless Markup Language (WML) HTML to imode (a variant of compact HTML) HTML to Handheld Device Markup Language (HDML) HTML to VoiceXML HTML to PalmOS HTML XML to XML variants using XSL stylesheets JPEG images to GIF and wireless bitmap GIF images to JPEG and wireless bitmap

46 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 46 W3C XSLT 2.0 Specification w3.org/style/xsl/ XSLT 2.0 has the following goals: <xsl:document> formalizes support for multiple output files Xalan, others currently have diverse mechanisms <xsl:script> for defining extension functions extension mechanisms varies for XSLT 1.0 implementations <xsl:apply-imports> element is allowed to have parameters (using <xsl:with-param> children) support for XML Base added result tree fragment data-type eliminated simplify manipulation of XML Schema-typed content simplify manipulation of string content support related XML standards improve ease of use, interoperability, i18n support maintain backward compatibility enable improved processor efficiency The following are explicitly not goals: simplify ability to parse unstructured information to produce structured results. turn XSLT into a general-purpose programming language

47 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 47 Summary XML is the language of e-business XSLT is a powerful transformation tool for business document and textual uses of XML, solves integration problems XSL Formatting Objects define a rich presentation format Many free and open source tools now available Apache Xalan is mature, robust, conformant...and your best choice.

48 XML One 2000 Repurpose your Data! The Role of XSL Transformations in e-business Architectures Page 48 Any Questions? XML Support sites ibm.com/alphaworks - site for free tools & emerging technologies from IBM. ibm.com/developerworks - site for tutorials, articles, code samples, news and other information to keep developers up to speed on XML, Web Services, Java, and other areas ibm.com/developerworks/speakers/colan Visit this site to find a PDF of this talk and the other XML and Web Services talks I give mcolan@us.ibm.com visit: ibm.com/developerworks/speakers/colan Presentation is available as a PDF at the web site listed above.