8/1/2016. XSL stands for EXtensible Stylesheet Language. CSS = Style Sheets for HTML XSL = Style Sheets for XML. XSL consists of four parts:

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1 XSL stands for EXtensible Stylesheet Language. CSS = Style Sheets for HTML XSL = Style Sheets for XML kasunkosala@yahoo.com 1 2 XSL consists of four parts: XSLT - a language for transforming XML documents XPath - a language for navigating in XML documents XSL-FO - a language for formatting XML documents (discontinued in 2013) XQuery - a language for querying XML documents XSLT (extensible Stylesheet Language Transformations) XSLT is the recommended style sheet language for XML. With XSLT you can transform an XML document into HTML. XSLT is far more sophisticated than CSS. With XSLT you can add/remove elements and attributes to or from the output file. You can also rearrange and sort elements, perform tests and make decisions about which elements to hide and display, and a lot more. 3 4 XSLT is a language for transforming XML documents into XHTML documents or to other XML documents. XSLT uses XPath to find information in an XML document. XSLT transforms an XML source-tree into an XML result-tree. <?xml version="1.0" encoding="utf-8"?> <?xml-stylesheet type="text/xsl" href="cdcatalog.xsl"?> <catalog> <cd> <title>empire Burlesque</title> <artist>bob Dylan</artist> <country>usa</country> <company>columbia</company> <price>10.90</price> <year>1985</year> </cd>.. </catalog> 5 6 1

2 <?xml version="1.0"?> <xsl:stylesheet version="1.0 xmlns:xsl=" <xsl:template match="/"> <h2>my CD Collection</h2> <table border="1"> <tr bgcolor="#9acd32"> <th>title</th> <th>artist</th> <xsl:for-each select="catalog/cd"> <tr> <td><xsl:value-of select="title"/></td> <td><xsl:value-of select="artist"/></td> </xsl:for-each> </table> </xsl:template> </xsl:stylesheet> <?xml version="1.0" encoding="utf-8"?> <xsl:stylesheet version="1.0" xmlns:xsl=" <xsl:template match="/"> <h2>my CD Collection</h2> <table border="1"> <tr bgcolor="#9acd32"> <th>title</th> <th>artist</th> <tr> <td>.</td> <td>.</td> </table> </xsl:template> </xsl:stylesheet> 7 8 The <xsl:value-of> element can be used to extract the value of an XML element and add it to the output stream of the transformation: <td> <xsl:value-of select="catalog/cd/title"/> </td> <td> <xsl:value-of select="catalog/cd/artist"/> </td> The XSL <xsl:for-each> element can be used to select every XML element of a specified node-set: <xsl:for-each select="catalog/cd"> <tr> <td><xsl:value-of select="title"/></td> <td><xsl:value-of select="artist"/></td> </xsl:for-each> 9 10 We can also filter the output from the XML file by adding a criterion to the select attribute in the <xsl:for-each> element. <xsl:for-each select="catalog/cd[artist='bob Dylan']"> Legal filter operators are: = (equal)!= (not equal) < less than > greater than The <xsl:sort> element is used to sort the output. <xsl:for-each select="catalog/cd"> <xsl:sort select="artist"/>..... </xsl:for-each>

3 The <xsl:if> element is used to put a conditional test against the content of the XML file. Syntax <xsl:if test="expression">...some output if the expression is true... </xsl:if> <xsl:if test="price > 10"> <tr> <td><xsl:value-of select="title"/></td> </xsl:if> The <xsl:choose> element is used in conjunction with <xsl:when> and <xsl:otherwise> to express multiple conditional tests. <xsl:choose> <xsl:when test="expression">... some output... </xsl:when> <xsl:otherwise>... some output... </xsl:otherwise> </xsl:choose> <xsl:choose> <xsl:when test="price > 10"> <td bgcolor="#ff00ff"> <xsl:value-of select="artist"/></td> </xsl:when> <xsl:otherwise> <td><xsl:value-of select="artist"/></td> </xsl:otherwise> </xsl:choose> XPath (the XML Path language) is a language for finding information in an XML document. XPath is a syntax for defining parts of an XML document XPath uses path expressions to navigate in XML documents XPath contains a library of standard functions XPath is a major element in XSLT XPath is also used in XQuery, XPointer and XLink XPath is a W3C recommendation XPath uses path expressions to select nodes or node-sets in an XML document. XPath expressions can also be used in JavaScript, Java, XML Schema, PHP, Python, C and C++, and lots of other languages. XPath is a major element in the XSLT standard

4 XPath Expression /bookstore/book[1] /bookstore/book[last()] /bookstore/book[last()-1] /bookstore/book[position()<3] /bookstore/book[price>35.00] Result First book element that is the child of the bookstore element Last book element that is the child of the bookstore element Last but one book element that is the child of the bookstore element First two book elements that are children of the bookstore element All the title elements that have an attribute named lang All the title elements that have a "lang" attribute with a value of "en" All the book elements of the bookstore element that have a price element with a value greater than All the title elements of the book elements of the /bookstore/book[price>35.00]/ bookstore element that have a price element with a value title greater than XLink is used to create hyperlinks in XML documents. Any element in an XML document can behave as a link With XLink, the links can be defined outside the linked files XLink is a W3C Recommendation 20 <?xml version="1.0" encoding="utf-8"?> <homepages xmlns:xlink=" <homepage xlink:type="simple" xlink:href=" </homepage> <homepage xlink:type="simple" xlink:href=" W3C </homepage> </homepages> W3Schools XPointer allows links to point to specific parts of an XML document XPointer uses XPath expressions to navigate in the XML document XPointer is a W3C Recommendation There is no browser support for XPointer. But XPointer is used in other XML languages XQuery is to XML what SQL is to database tables. XQuery is designed to query XML data - not just XML files, but anything that can appear as XML, including databases. You need an XQuery engine to "run" the query. Some blank space or other visible content exists before the <?xml?> declaration. Resolution: remove blank space or any other visible content before the XML declaration. Some invisible content exists before the <?xml?> declaration. Most commonly this is a Byte Order Mark (BOM). Resolution: Remove the BOM using techniques such as those suggested by the W3C page on the BOM in HTML. A stray <?xml?> declaration exists within the XML content. This can happen when XML files are combined programmatically or via cut-and-paste. There can only be one <?xml?> declaration in an XML file, and it can only be at the top. Resolution: Search for <?xml in a case-insensitive manner, and remove all but the top XML declaration from the file

5 XQuery is the language for querying XML data XQuery for XML is like SQL for databases XQuery is built on XPath expressions XQuery is supported by all major databases XQuery is a W3C Recommendation XQuery is a language for finding and extracting elements and attributes from XML documents. XQuery is compatible with several W3C standards, such as XML, Namespaces, XSLT, XPath, and XML Schema. Extract information to use in a Web Service Generate summary reports Transform XML data to XHTML Search Web documents for relevant information for $x in doc("books.xml")/bookstore/book where $x/price>30 return $x/title doc("books.xml")/bookstore/book/title The XQuery above will extract the following: <title lang="en">everyday Italian</title> <title lang="en">harry Potter</title> <title lang="en">xquery Kick Start</title> <title lang="en">learning XML</title> "Select all CD records with a price less than $10 from the CD collection stored in cd_catalog.xml" doc("books.xml")/bookstore/book[price<30] doc("books.xml")/bookstore/book[price>30]/t itle FLWOR (pronounced "flower") is an acronym for "For, Let, Where, Order by, Return". For - selects a sequence of nodes Let - binds a sequence to a variable Where - filters the nodes Order by - sorts the nodes Return - what to return (gets evaluated once for every node)

6 for $x in doc("books.xml")/bookstore/book where $x/price>30 return $x/title for $x in doc("books.xml")/bookstore/book where $x/price>30 return $x/title <ul> for $x in doc("books.xml")/bookstore/book/title order by $x return <li>$x}</li> } <ul> <li><title lang="en">everyday Italian</title></li> <li><title lang="en">harry Potter</title></li> <li><title lang="en">learning XML</title></li> <li><title lang="en">xquery Kick Start</title></li> <ul> for $x in doc("books.xml")/bookstore/book/title order by $x return <li>data($x)}</li> } <ul> <li>everyday Italian</li> <li>harry Potter</li> <li>learning XML</li> <li>xquery Kick Start</li> XQuery is case-sensitive XQuery elements, attributes, and variables must be valid XML names An XQuery string value can be in single or double quotes An XQuery variable is defined with a $ followed by a name, e.g. $bookstore XQuery comments are delimited by (: and :), e.g. (: XQuery Comment :)

7 for $x in doc("books.xml")/bookstore/book return if then <child>data($x/title)}</child> else <adult>data($x/title)}</adult> <adult>everyday Italian</adult> <child>harry Potter</child> <adult>xquery Kick Start</adult> <adult>learning XML</adult> In XQuery there are two ways of comparing values. 1. General comparisons: =,!=, <, <=, >, >= 2. Value comparisons: eq, ne, lt, le, gt, ge The following expression returns true if any q attributes have a value greater than 10: $bookstore//book/@q > 10 The following expression returns true if there is only one q attribute returned by the expression, and its value is greater than 10. If more than one q is returned, an error occurs: $bookstore//book/@q gt <h1>bookstore</h1> <ul> for $x in doc("books.xml")/bookstore/book return <li>data($x/title)}. Category: data($x/@category)}</li> } 40 <h1>bookstore</h1> <ul> <li>everyday Italian. Category: COOKING</li> <li>harry Potter. Category: CHILDREN</li> <li>learning XML. Category: WEB</li> <li>xquery Kick Start. Category: WEB</li> <h1>bookstore</h1> <ul> for $x in doc("books.xml")/bookstore/book return <li class="data($x/@category)}">data($x/title)}</li> }

8 <h1>bookstore</h1> <ul> <li class="cooking">everyday Italian</li> <li class="children">harry Potter</li> <li class="web">learning XML</li> <li class="web">xquery Kick Start</li> for $x in doc("books.xml")/bookstore/book where $x/price>30 return $x/title for $x in (1 to 5) return <test>$x}</test> Result: <test>1</test> <test>2</test> <test>3</test> <test>4</test> <test>5</test> for $x at $i in doc("books.xml")/bookstore/book/title return <book>$i}. data($x)}</book> Result: <book>1. Everyday Italian</book> <book>2. Harry Potter</book> <book>3. XQuery Kick Start</book> <book>4. Learning XML</book> Example 1: In an element <name>upper-case($booktitle)}</name> Example 2: In the predicate of a path expression doc("books.xml")/bookstore/book[substring(title, 1,5)='Harry'] Example 3: In a let clause let $name := (substring($booktitle,1,4)) declare function local:minprice($p as xs:decimal?,$d as xs:decimal?) as xs:decimal? let $disc := ($p * $d) div 100 return ($p - $disc) }; Below is an example of how to call the function above: <minprice>local:minprice($book/price,$book/discou nt)}</minprice>