xml basics
DESCRIPTION
XML Basics. A technical introduction Felix Eickhoff [email protected]. Overview. Why XML XML Fundamentals Document Type Definitions XML Schemas Namespaces in XML XSL Transformations X P ath X L inks X P ointers. Why XML. W3C endorsed standard Generic syntax to mark up data - PowerPoint PPT PresentationTRANSCRIPT
A technical introductionA technical introduction
Felix EickhoffFelix Eickhoff
[email protected]@gmx.net
XML Basics
Overview
Why XMLWhy XML XML FundamentalsXML Fundamentals Document Type DefinitionsDocument Type Definitions XML SchemasXML Schemas Namespaces in XMLNamespaces in XML XSL TransformationsXSL Transformations XXPPathath XXLLinksinks XXPPointersointers
Why XML
W3C endorsed standardW3C endorsed standard Generic syntax to mark up dataGeneric syntax to mark up data More flexible than HTMLMore flexible than HTML Need for sharing dataNeed for sharing data
XML Fundamentals
XML Version, DoctypeXML Version, Doctype ElementsElements
Start and End TagStart and End Tag AttributesAttributes Case sensitiveCase sensitive Contain other elements or dataContain other elements or data
CommentsComments Well formednessWell formedness
XML Fundamentals - Example<?xml version=„1.0“?><?xml version=„1.0“?><?DOCTYPE address-book SYSTEM „address-book.dtd“?><?DOCTYPE address-book SYSTEM „address-book.dtd“?><address-book><address-book> <entry><entry> <PersonName honorific=„Ms.“><PersonName honorific=„Ms.“> <SingleName>Doe</SingleName><SingleName>Doe</SingleName> <PersonName/><PersonName/> <address><address> <street>34 Fountain Square Plaza</street><street>34 Fountain Square Plaza</street> <postal-code>45202</postal-code><postal-code>45202</postal-code> </address></address> <tel prefered=„true“>515-73737</tel><tel prefered=„true“>515-73737</tel> <tel>515-28378</tel><tel>515-28378</tel> <email href=„mailto:[email protected]“/><email href=„mailto:[email protected]“/> </entry></entry> <entry><entry> <PersonName honrorifc=„Mr.“><FirstName>Jack</FirstName><PersonName honrorifc=„Mr.“><FirstName>Jack</FirstName> <MiddleName>Phillip</MiddleName><MiddleName>Phillip</MiddleName> <LastName>Smith</LastName></PersonName><LastName>Smith</LastName></PersonName> <tel>737-378477</tel><tel>737-378477</tel> <email href=„mailto:[email protected]“/><email href=„mailto:[email protected]“/> </entry></entry></address-book></address-book>
XML Trees – Example
F irs tN am e M id d leN am e L as tN am e
P erson N am e te l em a il
en try
ad d ress -b ook
Document Type Definitions - DTD Defines language grammar for a particular Defines language grammar for a particular
XML applicationXML application
What for:What for: Specific XML applicationsSpecific XML applications Validation of XML-filesValidation of XML-files
DTD - Example<!ELEMENT address-book (entry+)><!ELEMENT address-book (entry+)><!ELEMENT entry (name, address*, tel*, fax*, email*)><!ELEMENT entry (name, address*, tel*, fax*, email*)>
<!ELEMENT PersonName (SingleName|(FirstName, MiddleName*, <!ELEMENT PersonName (SingleName|(FirstName, MiddleName*, LastName))>LastName))><!ELEMENT FirstName (#PCDATA)><!ELEMENT FirstName (#PCDATA)><!ELEMENT MiddleName (#PCDATA)><!ELEMENT MiddleName (#PCDATA)><!ELEMENT LastName (#PCDATA)><!ELEMENT LastName (#PCDATA)><!ELEMENT SingleName (#PCDATA)><!ELEMENT SingleName (#PCDATA)>
<!ELEMENT address (street, postal-code><!ELEMENT address (street, postal-code><!ELEMENT street (#PCDATA)><!ELEMENT street (#PCDATA)><!ELEMENT postal-code (#PCDATA)><!ELEMENT postal-code (#PCDATA)>
<!ELEMENT tel (#PCDATA)><!ELEMENT tel (#PCDATA)><!ATTLIST tel preferred (true | false) „false“><!ATTLIST tel preferred (true | false) „false“><!ELEMENT fax (#PCDATA)><!ELEMENT fax (#PCDATA)><!ATTLIST fax preferred (true | false) „false“><!ATTLIST fax preferred (true | false) „false“><!ELEMENT email EMPTY><!ELEMENT email EMPTY><!ELEMENT email href CDATA #REQUIRED<!ELEMENT email href CDATA #REQUIRED preferred (true|false) „false“>preferred (true|false) „false“>
Document Type Defintions
Element DeclarationElement Declaration #PCDATA, EMPTY, ANY#PCDATA, EMPTY, ANY
SequencesSequences Using regular Expressions (* , + ,| )Using regular Expressions (* , + ,| )
Attribute DeclarationAttribute Declaration CDATA, NMTOKEN, ENUMERATION, ENTITY, CDATA, NMTOKEN, ENUMERATION, ENTITY,
ID, IDREF, NOTATION, #REQUIRED, #IMPLIED, ID, IDREF, NOTATION, #REQUIRED, #IMPLIED, #FIXED#FIXED
EntitiesEntities Internal and ExternalInternal and External
XML Schemas
Alternative to DTDAlternative to DTD XML SyntaxXML Syntax Data TypingData Typing Content ModelsContent Models ExtensibleExtensible Dynamic SchemasDynamic Schemas Self DocumentingSelf Documenting
XML - Example<?xml version=„1.0“?><?xml version=„1.0“?><?DOCTYPE address-book SYSTEM „address-book.xsd“<?DOCTYPE address-book SYSTEM „address-book.xsd“<address-book><address-book> <entry><entry> <PersonName honorific=„Ms.“><PersonName honorific=„Ms.“> <SingleName>Doe</SingleName><SingleName>Doe</SingleName> <PersonName/><PersonName/> <address><address> <street>34 Fountain Square Plaza</street><street>34 Fountain Square Plaza</street> <postal-code>45202</postal-code><postal-code>45202</postal-code> </address></address> <tel prefered=„true“>515-73737</tel><tel prefered=„true“>515-73737</tel> <tel>515-28378</tel><tel>515-28378</tel> <email href=„mailto:[email protected]“/><email href=„mailto:[email protected]“/> </entry></entry> <entry><entry> <PersonName honorific=„Mr.“><FirstName>Jack</FirstName><PersonName honorific=„Mr.“><FirstName>Jack</FirstName> <MiddleName>Phillip</MiddleName><MiddleName>Phillip</MiddleName> <LastName>Smith</LastName></PersonName><LastName>Smith</LastName></PersonName> <tel>737-378477</tel><tel>737-378477</tel> <email href=„mailto:[email protected]“/><email href=„mailto:[email protected]“/> </entry></entry></address-book></address-book>
XML Schema - Example<?xml version=„1.0“ ?><schema xmlns=„http://www.w3.org/2000/10/XMLSchema“>
<simpleType name=„Person Title“> <restriction base=„string“> <enumeration value=„Mr.“/> <enumeration value=„Ms.“/> </restriction></simpleType>
<complexType name=„Text“ content=„textonly“> <restriction base=„string“ /></complexType>
XML Schema – Example (2)<element name=„PersonName“> <complexType content=„element“> <choice> <element name=„Single Name“ type=„Text“ minOccurs=„1“ maxOccurs=„1“/> <sequence> <element name=„FirstName“ type=„Text“ minOccurs=„1“ maxOccurs=„1“/> <element name=„MiddleName“type=„Text“ minOccurs=„1“ maxOccurs=„unbounded“/> <element name=„LastName“ type=„Text“ minOccurs=„1“ maxOccurs=„1“/> </sequence> </choice> <attribute name=„honorific“ ref=„PersonTitle“/> </complexType></element>
...
</schema>
Namespaces in XML
Distinguish between elements and attributes Distinguish between elements and attributes from different XML applicationsfrom different XML applications
Group related elements and attributes Group related elements and attributes togethertogether
Based on unique Domain-NamesBased on unique Domain-Names
Namespace - Example<?xml version=„1.0“ ?>
<catalog> <painting> <title>Memory of the Garden of Etten</title> <artist>Vincent Van Gogh</artist> <date>November, 1888</date> <description> Two women ... </description> </painting>
<!– Many more paintings... -->
</catalog>
Namespace – Example(2)<?xml version=„1.0“ ?>
<RDF> <Description about=„http://name.com/impressionists.html“> <title>Impressionists Paintings</title> <creator>Joe Doe</creator> <description> A list of famous impressionist paintings organized by painter and date </description> <date>2001-10-05</date> </Description></RDF>
Namespace – Example(3)<?xml version=„1.0“ ?><catalog> <RDF> <Description about=„http://name.com/impressionists.html“> <title>Impressionists Paintings</title> <creator>Joe Doe</creator> <description> A list of famous impressionist paintings organized by painter and date </description> <date>2001-10-05</date> </Description> </RDF> <painting> <title>Memory of the Garden of Etten</title> <artist>Vincent Van Gogh</artist> <date>November, 1888</date> <description> Two women ... </description> </painting></catalog>
Namespace – Example(4)<?xml version=„1.0“ ?><catalog> <rdf:RDF xmlns:rdf=„http://www.w3.org./TR/REC-rdf-synstax#“> <rdf:Description xlmns:dc=„http://purl.org/dc“ about=„http://name.com/impressionists.html“> <dc:title>Impressionists Paintings</dc:title> <dc:creator>Joe Doe</dc:creator> <dc:description> A list of famous impressionist paintings organized by painter and date </dc:description> <dc:date>2001-10-05</dc:date> </rdf:Description> </rdf:RDF> <painting> <title>Memory of the Garden of Etten</title> <artist>Vincent Van Gogh</artist> <date>November, 1888</date> <description> Two women ... </description> </painting></catalog>
XSL Transformations
High-level language for defining XML High-level language for defining XML TransformationsTransformations
Format information for DisplayFormat information for Display Useful for managing data exchangeUseful for managing data exchange Report WritingReport Writing Work done by Stylesheet processorsWork done by Stylesheet processors
Stylesheet – Example Input<?xml version=„1.0“ ?><people> <person born=„1912“ died=„1954“> <name> <first_name>Alan</first_name> <last_name>Turing</last_name> </name> <profession>computer scientist</profession> <profession>mathematican</profession> <profession>cryptographer</profession> </person>
<person born=„1918“ died=„1988“> <name> <first_name>Richard</first_name> <middle_initial>M</middle_initial> <last_name>Feyman</last_name> </name> <profession>physicist</profession> <hobby>Playing the bongoes</hobby> </person></people>
Stylesheet – Example<?xml version=„1.0“?><xsl:stylesheet version=„1.0“ xmlns:xsl=„http://www.w3.org/1999/XSL/Transform“> <xsl:template match=„people“> <html> <head><title>Famous Scientists</title></head> <body> <dl> <xls:apply-templates/> </dl> </body> </html> </xsl:template>
Stylesheet – Example (2) <xsl:template match=„person“> <dt><xsl:apply-templates select=„name“/></dt> <dd><ul> <li>Born: <xsl:apply-templates select=„@born“/></li> <li>Died: <xsl:apply-templates select=„@died“/></li> </ul></dd> </xsl:template>
<xsl:template match=„name“> <xsl:value-of select=„last_name“/> <xsl:value-of select=„first_name“/> </xsl:template>
</xsl:stylesheet>
Stylesheet – Example Output<html> <head> <title>Famous Scientists</title> </head> <body> <dl> <dt> Alan Turing </dt> <dd> <ul> <li>Born: 1912</li> <li>Died: 1954</li> </ul> </dd>
...
</dl> </body</html>
XSL – More features
Uses XPath functionsUses XPath functions If-statements, For each loopsIf-statements, For each loops Parameters for templatesParameters for templates
=> Query language=> Query language
XPath
Identifies particular parts of XML Identifies particular parts of XML documentsdocuments
Navigate on the tree structures of XML Navigate on the tree structures of XML documents like in a UNIX file systemdocuments like in a UNIX file system
Many built-in functionsMany built-in functions e.g.:round, starts-with, substring, ...e.g.:round, starts-with, substring, ...
Used by XSLT, XPointerUsed by XSLT, XPointer
XPath – Example
b orn = "1 9 1 4 "d ied = "1 9 5 2 "
A lan
< firs t_ n am e> ...< /firs t_ n am e>
Tu rin g
< las t_ n am e> ...< /las t_ n am e>
< n am e> ...< /n am e>
C op m u ter S c ien tis t
< p ro fess ion > ...< /p ro fess ion >
< p erson > ...< /p erson >
S u b tree fo rn ext p erson
< p erson > ...< /p erson >
< p eop le> ...< /p eop le>
Th e roo t /
<xsl:template match=„people“> <xsl:apply-template select=„person“/></xsl:template>
<xsl:template match=„person“> <xsl:value-of select=„name“/></xsl:template>
XPath – Example (2)
b orn = "1 9 1 4 "d ied = "1 9 5 2 "
A lan
< firs t_ n am e> ...< /firs t_ n am e>
Tu rin g
< las t_ n am e> ...< /las t_ n am e>
< n am e> ...< /n am e>
C op m u ter S c ien tis t
< p ro fess ion > ...< /p ro fess ion >
< p erson > ...< /p erson >
S u b tree fo rn ext p erson
< p erson > ...< /p erson >
< p eop le> ...< /p eop le>
Th e roo t /
<xsl:template match=„person“> <xsl:apply-templates select=„@*“/></xsl:template>
<xsl:template match=„last_name|profession“> <xsl:value-of select=„.“/></xsl:template>
XPath – Example (3)
b orn = "1 9 1 4 "d ied = "1 9 5 2 "
A lan
< firs t_ n am e> ...< /firs t_ n am e>
Tu rin g
< las t_ n am e> ...< /las t_ n am e>
< n am e> ...< /n am e>
C op m u ter S c ien tis t
< p ro fess ion > ...< /p ro fess ion >
< p erson > ...< /p erson >
S u b tree fo rn ext p erson
< p erson > ...< /p erson >
< p eop le> ...< /p eop le>
Th e roo t /
/people/person/name/first_name//last_name/../first_name
<xsl:template match=„//profession[.=‚Computer Scientist‘]“><xsl:apply-template select=„//person[@born<=1980“/>
XLink
Simple LinksSimple Links Like Links in HTMLLike Links in HTML
Extended LinksExtended Links More than one target possibleMore than one target possible Directed labeled graphDirected labeled graph Representation undecided yetRepresentation undecided yet
ArcsArcs Links between other recourcesLinks between other recources
XLink – Simple Link Example<?xml version=„1.0“?>
<novel xmlns:xlink=„http://www.w3.org/1999/xlink“ xlink:type=„simple“ xlink:href=„ftp://someserver.com/books/novels/wizoz.txt“ xlink:actuate=„onRequest“ xlink:show=„replace“ xlink:title=„A Link to the wonderful wizard ...“ xlink:role=„http://moreinfo.com“>
<title>The wonderful wizard of oz</title> <author>Frank Baum</author></novel>
XLink – Extended Link Example<?xml version=„1.0“?>
<novel xmlns:xlink=„http://www.w3.org/1999/xlink“ xlink:type=„extended“> <title>The wonderful wizard of oz</title> <author>Frank Baum</author>
<edition xlink:type=„locator“ xlink:href=„urn:isbn:123456“ xlink:title=„William Morrow“ xlink:role=„http://www.williammorrow.com/“ xlink:label=„ISBN123456“/> <edition xlink:type=„locator“ xlink:href=„urn:isbn:234567“ xlink:title=„Oxford University Press“ xlink:role=„http://www.oup-usa.org/“ xlink:label=„ISBN234567“/>
</novel>
XLink – Arcs Example<?xml version=„1.0“?><series xlink:type=„extended“ xmlns:xlink=„http://www.w3.org/1999/xlink“> <author>Frank Baum</author>
<!–- locator elements --> <novel xlink:type=„locator“ xlink:label=„oz1“ xlink:href=„ftp://someserver.com/wizoz.txt“> <title>The wonderful wizard of oz</title> </novel>
<novel xlink:type=„locator“ xlink:label=„oz2“ xlink:href=„ftp://someserver.com/ozland.txt“> <title>The marvelous land of oz</title> </novel>
<novel xlink:type=„locator“ xlink:label=„oz3“ xlink:href=„ftp://someserver.com/ooz.txt“> <title>Ozma of oz</title> </novel>
XLink – Arcs Example (2)<!–- arcs --> <next xlink:type=„arc“ xlink:from=„oz1“ xlink:to=„oz2“ /> <next xlink:type=„arc“ xlink:from=„oz2“ xlink:to=„oz3“ /> <next xlink:type=„arc“ xlink:from=„oz2“ xlink:to=„oz1“ /> <next xlink:type=„arc“ xlink:from=„oz3“ xlink:to=„oz2“ />
</series>
The wonderfulworld of oz
The marvelousland of oz
Ozma ofoz
XPointer
Locates points in XML documentsLocates points in XML documents Based on XPathBased on XPath
In XLinks:http://www.someserver.com/xml/people.xml#xpointer (//name[position()=1])
xpointer(/) to the rootxpointer(//first_name)Xpointer(//profession[.=„physicist“])
References
XML in a NutshellXML in a NutshellElliotte Rusty Harold & W. Scott MeansElliotte Rusty Harold & W. Scott MeansO‘ReillyO‘Reilly
Professional XML DatabasesProfessional XML DatabasesKevin WilliamsKevin WilliamsWROXWROX
http://xml.coverpages.orghttp://xml.coverpages.org