06 - XML - XSLT

8/3/2019 06 - XML - XSLT

http://slidepdf.com/reader/full/06-xml-xslt 1/106

eXtensible Markup LanguageLectu rer : Phan Vo Minh Than g MSc.

eXtensible Markup Language

Using XSLT and XPath to Enhance HTMLDocuments

Thanks to Roger L. Costello

<?xml version=“1.0”><course startdate=“February 06, 2006”>

<title> eXtensible Markup Language </title><lecturer>Phan Vo Minh Thang</lecturer>

</course>

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<? xml version=“1.0”> <material> XML Lectures Notes <section id=“ 06 ”> XSLT </section> </material>

History

XSL

XSLXSLT

XSLTXPath

XLink/

XPointer

XQuery

XML

Schemas

(high-precision graphics, e.g., PDF)

(low-precision

graphics, e.g.,HTML,

text, XML)

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Note

For brevity, instead of using the term XSLT/XPath, I willsimply call it XSL.

? l i “1 0” t i l XML L t N t ti id “06” XSLT / ti / t i l

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Multiple Output Formats

XSL may be used to generate either HTML, XML, or text

XSL Processor

XSL

XML HTML (or XML or text)

? ml i “1 0” t i l XML Lect res Notes ti id “06” XSLT / ti / t i l

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xalan/xt/saxon

xalan: A free XSL processor, implemented in Java, from Apache(http://www.apache.org/)

xt: A free XSL processor, implemented in Java, from James Clark(http://www.jclark.com/)

saxon: A free XSL processor, implemented in Java, from Michael Kay(http://users.iclway.co.uk/mhkay/saxon

xalan/xt/saxon

XML XSL

HTML (or XML or text)

Invoking from a DOS command line:

run-xalan FitnessCenter.xml FitnessCenter.xsl FitnessCenter.htmlrun-xt FitnessCenter.xml FitnessCenter.xsl FitnessCenter.html

run-saxon FitnessCenter.xml FitnessCenter.xsl FitnessCenter.html

<?xml version “1 0”> <material> XML Lectures Notes <section id “06”> XSLT </section> </material>

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<? xml version= 1.0 > <material> XML Lectures Notes <section id= 06 > XSLT </section> </material>

Styling XML Documents using IE6 or Netscape7

Put a stylesheet PI at the top of your XML document. Now you can simply drop the XML document into the browser and the XML

will be automatically styled using the stylesheet referenced in the stylesheetPI.

<?xml version="1.0"?>

<?xml-stylesheet type="text/xsl" href="FitnessCenter.xsl"?>

<FitnessCenter><Member level="platinum">

<Name>Jeff</Name>

<Phone type="home">555-1234</Phone>

<Phone type="work">555-4321</Phone><FavoriteColor>lightgrey</FavoriteColor>

</Member>

</FitnessCenter>

Add this

stylesheetPI to the

top of

your XMLdocument

<?xml version=“1 0”> <material> XML Lectures Notes <section id=“06”> XSLT </section> </material>

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HTML Generation

We will first use XSL to generate HTML documents When generating HTML, XSL should be viewed as a tool to enhance

HTML documents.

• That is, the HTML documents may be enhanced by extracting dataout of XML documents

• XSL provides elements (tags) for extracting the XML data, thusallowing us to enhance HTML documents with data from an XML

document

<?xml version=“1 0”> <material> XML Lectures Notes <section id=“06”> XSLT </section> </material>

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Enhancing HTML Documents with XML Data

XMLDocument

HTML

Document(with embedded

XSL elements)

XSL element

XML data

XSLProcessor

XML data

<?xml version=“1.0”> <material> XML Lectures Notes <section id=“06”> XSLT </section> </material>

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<? xml version 1.0 > <material> XML Lectures Notes <section id 06 > XSLT </section> </material>

Enhancing HTML Documents with theFollowing XML Data

<?xml version="1.0"?><?xml-stylesheet type="text/xsl" href="FitnessCenter.xsl"?>

<FitnessCenter>

<Member level="platinum">

<Name>Jeff </ Name><Phone type="home">555-1234</ Phone>

<Phone type="work">555-4321</ Phone>

<FavoriteColor>lightgrey</ FavoriteColor></ Member>

</ FitnessCenter>

FitnessCenter.xml


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< e s o 0 > < ate a > ectu es otes <sect o d 06 > S </sect o > </ ate a >

Embed HTML Document in an XSL Template


<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"

version="1.0">

<xsl:output method="html"/>

<xsl:template match="/">

<HTML><HEAD>

<TITLE>Welcome</TITLE></HEAD><BODY>

Welcome!</BODY>

</HTML></xsl:template>

</xsl:stylesheet>

FitnessCenter.xsl (see html-example01)

Note how we

have the HTML

document

embedded withian XSL template


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Note

The HTML is embedded within an XSL template, which isan XML document

• Consequently, the HTML must be well formed, i.e.,

every start tag must have an end tag

Because the HTML is embedded within an XSL template,we are able to add XSL elements to the HTML, allowing

us to extract data out of XML documents

Let's customize the HTML welcome page by putting in themember's name. This is achieved by extracting the namefrom the XML document. We use an XSL element to dothis.


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Extracting the Member Name



version="1.0">



<HTML>

<HEAD>

<TITLE>Welcome</TITLE></HEAD>

<BODY>

Welcome <xsl:value-of select="/FitnessCenter/Member/Name"/>!</BODY>


</xsl:stylesheet>

(see html-example02)


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Note

Notice how we have enhanced the HTML document byusing data from the XML document!


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Extracting a Value from an XML Document,Navigating the XML Document

Extracting values:

• use the <xsl:value-of select="…"/> XSL element

Navigating:

• The slash ("/") indicates parent/child relationship

• A slash at the beginning of the path indicates that it isan absolute path, starting from the top of the XMLdocument

/FitnessCenter/Member/Name

"Start from the top of the XML document, go to the FitnessCenter element,

from there go to the Member element, and from there go to the Name element."


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Document /

PI<?xml version=“1.0”?>

ElementFitnessCenter

ElementMember

ElementName

ElementPhone

ElementPhone

ElementFavoriteColor

TextJeff

Text555-1234

Text555-4321

Textlightgrey


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Extract the FavoriteColor and use it as the bgcolor



version="1.0">



<HTML>

<HEAD>

<TITLE>Welcome</TITLE></HEAD>

<BODY bgcolor="{/FitnessCenter/Member/FavoriteColor}">Welcome <xsl:value-of select="/FitnessCenter/Member/Name"/>!

</BODY>


</xsl:stylesheet>



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Note

Attribute values cannot contain "<" nor ">"

- Consequently, the following is NOT valid:

<Body bgcolor="<xsl:value-of select='/FitnessCenter/Member/FavoriteColor'/>">

To extract the value of an XML element and use it as an attribute

value you must use curly braces:<Body bgcolor="{/FitnessCenter/Member/FavoriteColor}">

Evaluate the expression within

the curly braces. Assign the value

to the attribute.


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Extract the Home Phone Number

<?xml version="1.0"?><xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"

version="1.0">



<HTML>

<HEAD>

<TITLE>Welcome</TITLE>

</HEAD><BODY bgcolor="{/FitnessCenter/Member/FavoriteColor}">

Welcome <xsl:value-of select="/FitnessCenter/Member/Name"/>!

<BR/>

Your home phone number is:

<xsl:value-of select="/FitnessCenter/Member/Phone[@type='home']"/></BODY>

</HTML>

</xsl:template>

</xsl:stylesheet>



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Note

In this example we want "the Phone element where the value

of its type attribute equals 'home' ":

<xsl:value-of select="/FitnessCenter/Member/Phone[@type='home']"/>

The expression within […] is called a "predicate". Its purposeis to filter.

Note the use of the single quotes within the double quotes.select=" … ' …' …"


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Review - HTML Table

<table border=“1” width=“100%”>

</table>

<tr>

<tr>

<tr> </tr>

</tr>

</tr><th>

</th><th>

</th><th>

</th>

<td>

</td>

<td>

</td><td>

</td>

<td></td>

<td></td>

<td></td>

This will create a table with 3 rows - the first row contains a header

for each column. The next two rows contains the table data.


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<table border=“1” width=“75%”>

<tr><th>Fruit</th>

<th>Color</th>

</tr>

<tr>

<td>Papaya</td>

<td>Red</td>

</tr>

<tr>

<td>Banana</td>

<td>Yellow</td>

</tr>

</table>

Fruit Color

Papaya Red

Banana Yellow


C T bl f Ph N b

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Create a Table of Phone Numbers

Suppose that a Member has an arbitrary number of phonenumbers (home, work, cell, etc).

Create an HTML table comprised of the phone numbers.

On each row of the table put the type (home, work, cell,etc) in one column and the actual phone number in thenext column.


<? l i "1 0"?>

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version="1.0">



<HTML>

<HEAD>




<BR/>

Your phone numbers are:

<TABLE border="1" width="25%"><TR><TH>Type</TH><TH>Number</TH></TR><xsl:for-each select="/FitnessCenter/Member/Phone">

<TR><TD><xsl:value-of select="@type"/></TD><TD><xsl:value-of select="."/></TD>

</TR></xsl:for-each>

</TABLE></BODY>

</HTML>

</xsl:template>

</xsl:stylesheet>



It ti th h XML El t

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Iterating through XML Elements

<xsl:for-each select="/FitnessCenter/Member/Phone">

<!- - Within here we are at one of the Phone elements.

Thus, in <xsl:value-of select=" path", the value for

path is relative to where we are in the XMLdocument. The "." refers to the Phone element

that we are currently positioned at. - ->

</xsl:for-each>


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Absolute Path versus Relative Path

<xsl:value-of select="/FitnessCenter/Member/Phone[@type='home']"/

This is an absolute xPath expression

(we start from the top of the XML tree

and navigate down the tree)

<xsl:value-of select="@type"/>

This is a relative xPath expression (relative

to where we currently are located, give me

the value of the type attribute)

Do Lab1,

Parts 1-3


Special Offer to Platinum Members

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Special Offer to Platinum Members

Let's further enhance our example to provide a specialoffer to "platinum" members.

We need to check to see if the "level" attribute on the

Member element equals "platinum".


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<HTML>

<HEAD>




<BR/>

<xsl:if test="/FitnessCenter/Member/@level='platinum'">

Our special offer to platinum members today is ...<BR/>

</xsl:if>Your phone numbers are:

<TABLE border="1" width="25%">

<TR><TH>Type</TH><TH>Number</TH></TR><xsl:for-each select="/FitnessCenter/Member/Phone">

<TR>

<TD><xsl:value-of select="@type"/></TD>

<TD><xsl:value-of select="."/></TD>


</TABLE>

</BODY>

</HTML>



Conditional Processing

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Conditional Processing

Use the <xsl:if test="…"/> element to perform conditionalprocessing.

Do Lab1,

Part 4


Accessing Multiple Parts of the XML

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Accessing Multiple Parts of the XMLDocument Let's enhance the table to contain three columns - the

name of the Member, the type of the phone (home, work,cell, etc), and the actual phone number.


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<HTML>

<HEAD>




<BR/>

<xsl:if test="/FitnessCenter/Member/@level='platinum'">

Our special offer to platinum members today is ...<BR/>

</xsl:if>

Your phone numbers are:


<TR><TH>Name</TH><TH>Type</TH><TH>Number</TH></TR><xsl:for-each select="/FitnessCenter/Member/Phone">

<TR>

<TD><xsl:value-of select="../Name"/></TD><TD><xsl:value-of select="@type"/></TD>

<TD><xsl:value-of select="."/></TD>

</TR>

</xsl:for-each>

</TABLE>

</BODY>

</HTML>



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Getting the Name when accessing the

Phone

Member

Phone

555-1234

Phone

555-4321

Name

Jeff

Notice how

when in the for-eachloop we need to access

the Name which is "up

and over" with respect

to the Phone element

Bottom line: we can access elements in other parts of the XML tree via the “../” operator.


Other ways to Access the XML Data

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Other ways to Access the XML Data

<xsl:value-of select="/FitnessCenter/Member[1]/Name"/>

"Select the Name of the first Member"

<xsl:value-of select="/FitnessCenter/Member[position()=1]/Name"/>

"Select the Name of the first Member"

<xsl:value-of select="/FitnessCenter/Member[last()]/Name"/>

"Select the Name of the last Member"

<xsl:for-each select="/FitnessCenter/Member[not(position()=last())]">

<!- - Process all Members but the last - ->

</xsl:for-each>

Note: Assume that there are multiple Members


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Other ways to Access the XML Data (cont.)

<xsl:for-each select="/FitnessCenter/Member[position() != last())]">

<!- - Process all Members but the last - -></xsl:for-each>

<xsl:for-each select="/FitnessCenter/Member[position() >1]">

<!- - Process all Members but the first - ->

</xsl:for-each>

<xsl:for-each select="/FitnessCenter//Name"><!- - Process all Name elements which have FitnessCenter

as an ancestor - ->

</xsl:for-each>


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Other ways to Access the XML Data (cont.)

<!- - Iterate through a list of Member nodes - ->

<xsl:for-each select="/FitnessCenter/Member">

<!- - Output the Name of the "current" Member - ->

<xsl:value-of select="./Name"/>

</xsl:for-each>

<!- - Since a specific Member is not specified, all Member nodes - ->

<!- - all selected. That is, the Name node within each Member - ->

<xsl:for-each select="/FitnessCenter/Member/Name">

<xsl:value-of select="."/>

</xsl:for-each>


Nodelist

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Nodelist

This xPath expression:

/FitnessCenter/Member

selects a list of nodes (a list of Member nodes).This list of nodes is called a "nodelist".


Enhanced XML Document

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<FitnessCenter>

<Member id="1" level="platinum">

<Name>Jeff </ Name>

<Phone type="home">555-1234</ Phone>


<FavoriteColor>lightgrey</ FavoriteColor>

</ Member>

<Member id="2" level="gold">

<Name>David</ Name>

<Phone type="home">383-1234</ Phone><Phone type="work">383-4321</ Phone>

<FavoriteColor>lightblue</ FavoriteColor>

</ Member>


<Name>Roger</ Name><Phone type="home">888-1234</ Phone>


<FavoriteColor>lightyellow</ FavoriteColor>

</ Member>

</ FitnessCenter>

Note that each Member

now has a unique id

(the id attribute)


Review - HTML Hyperlinking

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Review HTML Hyperlinking

<A name="AnnaAndTheKing"></A>

…

<A href="#AnnaAndTheKing">Click Here</A>

...

This creates an internal hyperlink (the source "anchor" links to

the target anchor).


Hyperlink Name to Home Phone

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yp

Problem: create an HTML document that has two tables -a Member Name table, and a Member home Phonenumber table.

Hyperlink the Member's Name to his/her Phone.


<TABLE border "1" width "25%">

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<TR><TH>Name</TH></TR>


<TR>

<TD>

<A href="#{@id}">

<xsl:value-of select="Name"/></A>

</TD>

</TR>

</xsl:for-each>

</TABLE>

<BR/><BR/><BR/><BR/><BR/><TABLE border="1" width="25%">

<TR><TH>Home Phone Number</TH></TR>


<TR>

<TD><A name="{@id}"><xsl:value-of select="Phone[@type='home']"/>

</A></TD>


</TABLE>


Do Lab1,

Parts 5-6


Numbering

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Numbering

There is an XSL element that returns a numbercorresponding to the element's position in the set ofselected nodes



<xsl:number value="position()" format="1"/><xsl:text>. </xsl:text>

<xsl:value-of select="Name"/>

<BR/>

</xsl:for-each> Output:1. Jeff

2. David

3. Roger


Start Numbering from 0

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g

How would you start the numbering from zero, rather thanone?

<xsl:number value="position() - 1" format="1">


format attribute of xsl:number

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In the previous example we saw how to generatenumbers, and we saw that the generated numbers were 1,2, 3, etc.

With the format attribute we can specify the format of thegenerated number, i.e., 1, 2, 3 or I, II, III, or A, B, C, or …

• format=“1” generates the sequence: 1, 2, 3, …

• format=“01” generates: 01, 02, 03, …

• format=“A” generates: A, B, C, …

• format=“a” generates: a, b, c, …

• format=“I” generates: I, II, III, …

• format=“i” generates: i, ii, iii, ...


format attribute of xsl:number

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<xsl:number value="position()" format="A"/><xsl:text>. </xsl:text>

<xsl:value-of select="Name"/>

<BR/></xsl:for-each>

Output:A. Jeff

B. David

C. Roger


Sorting

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Sorting

There is an XSL element that sorts the elements thatyou extract from the XML document


<xsl:sort select="Name" order="ascending"/><xsl:value-of select="Name"/>

<BR/>

</xsl:for-each>

"For each Member, sort the Name elements"

Output:

DavidJeff

Roger



Sorting

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<xsl:sort select="Name" order="ascending"/><xsl:value-of select="Name"/>

<BR/>

</xsl:for-each>

The set of Member elements selected by xsl:for-each is

sorted using the Name child element. This occurs prior

to the first iteration of the loop. After the set of Memberelements are sorted then the looping begins.


concat() function

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concat(destination string , string to add )

Note: if you want to concatenate more than one string tothe destination string then simply add more arguments


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<xsl:value-of select="concat('Welcome ', Name, '!')"/>

<BR/>

</xsl:for-each>

Output:

Welcome Jeff!

Welcome David!

Welcome Roger!


xsl:variable

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Hello World

This XSL element allows you to create a variable to hold a value (which could

be a string or a subtree of the XML document).

The variable is referenced by $variable-name

<xsl:variable name=“hello” select=“'Hello World'”/>

This creates a variable called hello, that has a value which is the literal string, ‘Hello World’.

We could use this variable as follows:

Value = <xsl:value-of select=“$hello”/>

This will output:

Value = Hello World

hello

<? xml

version=“1.0”> <material> XML Lectures Notes

<section id=“ 06

”> XSLT

</section> </material>

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Member's Phone Numbers:<TABLE border="1" width="25%">

<TR><TH>Name</TH><TH>Type</TH><TH>Number</TH></TR>


<xsl:variable name="name" select="Name"/><xsl:for-each select="Phone">

<TR>

<TD><xsl:value-of select="$name"/></TD>


<TD><xsl:value-of select="."/></TD></TR>

</xsl:for-each>

</xsl:for-each>

</TABLE>


<? xml


<section id=“ 06

”> XSLT


xsl:variable

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<xsl:variable name=“member” select=“Member[1]”/>

This creates a variable called member, that has a value which is a subtree.

We could use this variable as follows:

Name = <xsl:value-of select=“$member/Name”/>

Home Phone = <xsl:value-of select=“$member/Phone[@type='home']”/>

This will result in generating:

Name = Jeff

Home Phone = 555-1234

Member

...Name Phone Phone

Jeff 555-1234 555-4321

<? xml


<section id=“ 06

”> XSLT


xsl:variable

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A variable is “write once, read many”.

• That is, you can assign a variable a value only once, but then youcan retrieve the value of the variable many times.

A variable has a scope limited to the XSL element that it isnested within. Its scope starts where it is defined andextends to the end of the XSL element that it is nestedwithin.

<? xml


<section id=“ 06

”> XSLT


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Member's Phone Numbers:<TABLE border="1" width="25%">

<TR><TD>Name</TD><TD>Type</TD><TD>Number</TD></TR>


<xsl:variable name="name" select="Name"/><xsl:for-each select="Phone">

<TR>

<TD><xsl:value-of select="$name"/></TD>


<TD><xsl:value-of select="."/></TD></TR>

</xsl:for-each>

</xsl:for-each>

</TABLE>

The name variable's life ends hereDo Lab2,

Part 1

<? xml


<section id=“ 06

”> XSLT


Global Variables

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You can create a variable outside of <xsl:template match="/">. Then,

the variable is global.



version="1.0">


<xsl:variable name="pi" select="'3.142857142857'"/>

<xsl:template match="/" >

<HTML>

<HEAD>

<TITLE>Value of Pi</TITLE>

</HEAD>

<BODY>

The value of pi = <xsl:value-of select="$pi"/></BODY>

</HTML>

</xsl:template>

<? xml


<section id=“ 06

”> XSLT


Problem

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Suppose that we want to create a variable, names, and we want this

variable to contain a list of the Member Names, with each nameseparated by a slash. How would you create such a variable?

Here’s what you might attempt to do:

Member's Names:

<xsl:variable name="names" select="/FitnessCenter/Member[1]/Name"/>

<xsl:for-each select="/FitnessCenter/Member[position() > 1]">

<xsl:variable name="names" select="concat($names, '/')"/><xsl:variable name="names" select="concat($names, Name)"/>

</xsl:for-each>

<xsl:value-of select="$names"/>

Output:

Jeff


<? xml


<section id=“ 06

”> XSLT


Let’s add some statements to trace this example

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<xsl:variable name="names" select="/FitnessCenter/Member[1]/Name"/>

<xsl:value-of select="$names"/><BR/>


<xsl:variable name="names" select="concat($names, '/')"/>


<xsl:variable name="names" select="concat($names, Name)"/>


</xsl:for-each><xsl:value-of select="$names"/>

Output:

Jeff Jeff/

Jeff/David

Jeff/ <--- Why did we loose the previous Name? That name went out of scope.

Jeff/Roger

Jeff Obviously, this approach doesn’t work. So how do we do it?


<? xml


<section id=“ 06

”> XSLT


Here’s what we would like to do

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names

Open up the

names box


Add this iteration’s Name and a slash to the open names box

</xsl:for-each>

Iterate through

each name, adding into

the open box

Jeff/David/RogerClose the box

names

Jeff … / … David … / … Roger

<? xml


<section id=“ 06

”> XSLT


Problem - Solution

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In all previous examples of creating a variable we declared the name of the

variable and then had a select attribute which gave the variable its value.

We can omit the select attribute:

<xsl:variable name=“names”>

- Do stuff in here. All output will go into the names “box”.

</xsl:variable>


Problem - Solution

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Member's Names:

<xsl:variable name="names"><xsl:value-of select="/FitnessCenter/Member[1]/Name"/>


<xsl:text>/</xsl:text>

<xsl:value-of select="Name"/></xsl:for-each>

</xsl:variable><xsl:value-of select="$names"/>


Output:

Member's Names: Jeff/David/Roger


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contains() function

contains(string to be tested, test string) returns true if

string to be tested contains test string

<xsl:if test=“contains($greeting, ‘welcome’)”>

$greeting contains ‘welcome’

</xsl:if>

Do Lab2,

Part 2


xsl:choose

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xsl:choose allows you to elegantly express multipleconditional tests. Here’s the structure:

<xsl:choose>

<xsl:when test='something>[action]

</xsl:when>

<xsl:when test='something'>

[action]

</xsl:when><xsl:otherwise>

[action]

</xsl:otherwise>

</xsl:choose>

The first xsl:when statement that

evaluates to true is executed. If

none evaluates to true then the

xsl:otherwise statement is

executed.


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Implementing an if-then-else

There is no if-then-else element in XSL.

However, there is an elegant way to do it:

<xsl:choose>

<xsl:when test="contains($member-list, 'Jeff')"><xsl:text>Jeff is a member</xsl:text>

</xsl:when>

<xsl:otherwise>

<xsl:text>No member by the name Jeff</xsl:text>

</xsl:otherwise></xsl:choose>


substring-before() String Function

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Here’s the form of this string function:

substring-before(string, pattern)

Example:

<xsl:variable name="phone" select="Phone"/>

<xsl:value-of select="substring-before($phone, '-')"/>

“Get the contents of Phone and put it into the variable

called ‘phone’. Then extract from the content of ‘phone’ the string

before the '-' (i.e., the telephone exchange)”.

555-1234substring-before($phone, ‘-’)

555

phone


substring-after() String Function

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substring-after(string, pattern)

Example:

<xsl:variable name="phone" select="Phone"/>

<xsl:value-of select="substring-after($phone, '-')"/>

“Get the contents of Phone and put it into the variable

called ‘phone’. Then extract from the content of ‘phone’ the string

after the '-'”.

555-1234substring-after($phone, ‘-’)

1234

phone


starts-with() String Function

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starts-with(string, pattern)

Example:

<xsl:if test="starts-with(Phone, '555')">

[action]

</xsl:if>

“If the Phone starts with the

string, ‘555’ then do [action]”.


substring() function

substring(string i len?) returns the substring of string that

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substring(string , i , len? ) returns the substring of string that

starts at the i th position and has length, len . The lengthargument (len ) is optional. If not present then this functionreturns the substring starting at the i th position all the way

to the end of the string. Note: the first character is atposition 1 (not 0 as with some languages)

substring(‘1234567890’, 2, 5) returns ‘23456’


string-length() function

string length(string) returns the length of the string

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string-length(string ) returns the length of the string

string-length(‘1234567890’) returns 10


translate() function

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translate(string, from-pattern, to-pattern)

Example. translate(“Hello”, “ABCDEFGHIJKLMNOPQRSTUVWXYZ”,

“abcdefghijklmnopqrstuvwxyz”);

this will convert Hello to hello (i.e., convert to lower case)

A better approach to the above problem is:

<xsl:variable name="upperCaseChars" select=" 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' "/>

<xsl:variable name="lowerCaseChars" select=" 'abcdefghijklmnopqrstuvwxyz' "/>

translate(“Hello”, $upperCaseChars, $lowerCaseChars)

Note: need to put the stringwithin (single) quotes, otherwise

the XSL Processor will try to

interpret it as an XML element.

Do Lab2,

Part 3


Boolean and Relational Operators

Boolean operators: not and or

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Boolean operators: not, and, or

Relational operators: <, >, =, <=, >=, !=

The less than and greater than signs are reserved

symbols, so they need to be escaped when you use them.Thus, the relational operators will appear in your XSL codelike this:

< > = <= >= !=

< > = <= >= !=

Want this:

Use this:


Arithmetic

The arithmetic operators available: + - * div mod

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The arithmetic operators available: +, -, , div, mod

(remainder from doing a division)

• Note: recall that an XML element can have a dash in the name.So, if you want to indicate subtraction, be sure to surround “-” with

blank spaces.


Arithmetic functions

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sum(node set ) this function sums up all the values in the set of nodes

floor(number ) returns the largest integer that is not greater than number • Example. floor(2.5) returns 2

ceiling(number ) returns the smallest integer that is not less thannumber

• Example. Ceiling(2.5) returns 3

round(number ) returns the integer closest to number

• Example. round(2.3) returns 2



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<FitnessCenter>


<Name>Jeff </ Name>


<Phone type="work">555-4321</ Phone><FavoriteColor>lightgrey</ FavoriteColor>

<MembershipFee>340</ MembershipFee>

</ Member>

<Member id="2" level="gold">

<Name>David</ Name>

<Phone type="home">383-1234</ Phone><Phone type="work">383-4321</ Phone>

<FavoriteColor>lightblue</ FavoriteColor>


</ Member>


<Name>Roger</ Name>



<FavoriteColor>lightyellow</ FavoriteColor>


</ Member></ FitnessCenter>

Note that each Member

now has MembershipFee

element


Compute Membership Revenue

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Membership Fee Revenue:

<xsl:value-of select="sum(//MembershipFee)"/>



xsl:attribute

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xsl:attribute

This XSL element is used by nesting it within an

output element. It enables you to create an attributefor the output element


Coloring alternate rows

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Member Names:


<xsl:for-each select="/FitnessCenter/Member"><TR>

<xsl:if test="position() mod 2 = 0"><xsl:attribute name="bgcolor">yellow</xsl:attribute>

</xsl:if><TD><xsl:value-of select="Name"/></TD>

</TR>

</xsl:for-each>

</TABLE>


For each even row of the table, the TR value will be:

<TR bgcolor="yellow">


count() function

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count(set of node) returns an integer representing the number

of nodes (i.e., XML elements) in the set.

Example.

Number of members =

<xsl:value-of select="count(//Member)"/>

Output:

Number of members = 5 Do Lab2,

Part 4


Selecting all Elements/Attributes

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<xsl:for-each select="@*">...

</xsl:for-each>

<xsl:for-each select="*">

...

</xsl:for-each></xsl:for-each>

For eachattribute do ...

For each

child element

do ...


Getting the Name of the Element/Attributeusing the name() Function

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<xsl:for-each select="/FitnessCenter/Member"><xsl:for-each select="@*">

Attribute = <xsl:value-of select="name(.)"/>

</xsl:for-each>

<xsl:for-each select="*">

Element = <xsl:value-of select="name(.)"/>

</xsl:for-each></xsl:for-each>


name(node) returns the name of "node"


When to use Curly Braces?

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“When I assign an attribute a value, when do I use curly braces and when do Inot use them?”

Use curly braces for these attributes:

- the attribute of a literal result element (where you literally type what shouldbe output)

Example: <a href=“#{@id}”>

- the name attribute of xsl:attribute

Example: <xsl:attribute name =“{@value}”>

- the name attribute of xsl:piExample: <xsl:pi name =“{@value}”>

- the name attribute of xsl:element

Example: <xsl:element name =“{@value}”>

- the optional attributes of xsl:sort:Example: <xsl:sort order =“{@value}”>

lang =“{@value}”>

data-type =“{@value}”>

case-order =“{@value}”>


document( ) Function

This function enables you to access other XML documents

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(besides the XML document that you specify when youinvoke the XSL Processor).

The format for using the document() function is:document(url ), where url is a URL to another XMLdocument


Fitness Centers Merger

Another fitness center has just merged with us. They have

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an xml document (FitnessCenter2.xml) containing theirMembers.

You are to create an XSL-enhanced HTML document thatcreates a single table comprised of all the Members fromboth fitness clubs.



<TR><TH>Name</TH><TH>Phone(home)</TH>...</TR>


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<TR><TD><xsl:value-of select="Name"/></TD>

<TD><xsl:value-of select="Phone[@type='home']"/></TD>

<TD><xsl:value-of select="Phone[@type='work']"/></TD>

<TD><xsl:value-of select="FavoriteColor"/></TD>

</TR>

</xsl:for-each>

<xsl:variable name="fitnessCenter2"select="document('file://localhost/xml-course/.../FitnessCenter2.xml')"/>

<xsl:for-each select="$fitnessCenter2/FitnessCenter/Member"><TR>

<TD><xsl:value-of select="Name"/></TD>

<TD><xsl:value-of select="Phone[@type='home']"/></TD>

<TD><xsl:value-of select="Phone[@type='work']"/></TD><TD><xsl:value-of select="FavoriteColor"/></TD>

</TR>

</xsl:for-each>

</TABLE>


Do Lab3,

Part 1


Parameterized Processing

You can create a subroutine (called a named template),

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and you can pass to it parameters.



<HTML>

<HEAD>

<TITLE>Fitness Center</TITLE>

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</HEAD><BODY>

<xsl:call-template name="displayNameWithFont">

<xsl:with-param name="fontFace" select="'Impact'"/><xsl:with-param name="name"

select="/FitnessCenter/Member[1]/Name"/></xsl:call-template>

<BR/>

...

</BODY>

</HTML>

</xsl:template>

<xsl:template name="displayNameWithFont"><xsl:param name="fontFace" select="'Braggadocio'"/> <xsl:param name="name"/><FONT face="{$fontFace}">

<xsl:value-of select="$name"/></FONT>

</xsl:template>(see html-example21)


Call by Reference

How do we create a named template that returns a value?

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Example: create a named template which, when passed anumber, it returns the number div 2.



<HTML>

<HEAD>

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<TITLE>Fitness Center</TITLE></HEAD>

<BODY>

16 / 2 =

<xsl:variable name="result"><xsl:call-template name="NumDiv2"><xsl:with-param name="N" select="16"/>

</xsl:call-template></xsl:variable>

<xsl:value-of select="$result"/></BODY>

</HTML>

</xsl:template>

<xsl:template name="NumDiv2">

<xsl:param name="N"/>

<xsl:value-of select="$N div 2"/>

</xsl:template>(see html-example22)


Problem: Determine if all <Number> valuesare <= 100

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<?xml version="1.0"?><NumberList>

<Number>23</Number>

<Number>41</Number>

<Number>70</Number><Number>103</Number>

<Number>99</Number>

<Number>6</Number></NumberList>

(see html-example22-1)



<xsl:text>All numbers in the list are less than or equal to 100: </xsl:text>

<xsl:variable name="result">

<xsl:call-template name="AllLessThan100">

<xsl:with-param name="numberList" select="NumberList/Number"/>

/ l ll l

Pass to the named

template a list of

b d

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</xsl:call-template></xsl:variable>

<xsl:value-of select="$result"/>

</xsl:template>

<xsl:template name="AllLessThan100">

<xsl:param name="numberList"/>

<xsl:choose><xsl:when test="not($numberList)">

<xsl:text>true</xsl:text>

</xsl:when>

<xsl:otherwise>

<xsl:choose>

<xsl:when test="$numberList[1] > 100">

<xsl:text>false</xsl:text>

</xsl:when>

<xsl:otherwise>

<xsl:call-template name="AllLessThan100">

<xsl:with-param name="numberList" select="$numberList[position() > 1]"/>

</xsl:call-template>

</xsl:otherwise></xsl:choose>

</xsl:otherwise>

</xsl:choose>

</xsl:template>

Do Lab3,Part 2

<Number> nodes,i.e., a nodelist.

This is a recursive routine

If the nodelist is empty

then return true

Check the first node onthe list. If it's greater

than 100, then return

false (and we're done).

Otherwise, recurse over theremaining nodes.


generate-id()

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Use this function to generate a unique string for a

node

Example. generate-id(/FitnessCenter/Member[1]) will return a unique id for the first Member


Using generate-id() to Uniquely IdentifyElements In html-example08 we created two tables - a table

t i i th M b N d t t bl

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containing the Members Names, and a separate tablecontaining home Phone numbers. Each Name washyperlinked to his/her home Phone. We used the id

attribute on each Member element to link the two tablestogether.

Suppose there is no id attribute. We can use generate-id()

to create a unique identifier.



<TR><TH>Name</TH></TR>


<TR>

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<TR><TD>

<A href="#{generate-id(.)}">

<xsl:value-of select="Name"/></A>

</TD></TR>

</xsl:for-each>

</TABLE>

<BR/><BR/><BR/><BR/><BR/>

<TABLE border="1" width="25%"><TR><TH>Home Phone Number</TH></TR>


<TR>

<TD>

<A name="{generate-id(.)}"><xsl:value-of select="Phone[@type='home']"/>

</A></TD>

</TR>

</xsl:for-each></TABLE>



Same (XML) Data, Multiple Views

In html-example24 I show how to create an HTML

d m t th t ll li t t i XML d m t i

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document that allows a client to view an XML document indifferent forms.

Look at html-example24. With the buttons on the left side

of the screen we can select which view is desired.


Multiple Stylesheets to provide the different views

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FitnessCenter.xml

ShowMembers.xsl ShowPlatinumMembers.xsl ShowGoldMembers.xsl ShowAll.xsl


FitnessCenter.html - comprised of two frames

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FitnessCenter.html

Controls.html Body.html

ShowMembers

ShowPlatinumMembers

ShowGoldMembers

ShowAll

RawXML


FitnessCenter.html

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<HTML>

<HEAD><TITLE>Welcome</TITLE>

</HEAD>

<FRAMESET cols="20%,80%">

<FRAME src="controls.html" name="controlsFrame"><FRAME src="body.html" name="bodyFrame">

</FRAMESET>

</HTML>

FitnessCenter.html

Two columns.

The first columnis 20% of the width

of the screen. The

second column is

80% of the width

of the screen.

NOTE: do NOT have a <BODY> element (it won't work if you do)


Body.html

<HTML>

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<HTML><HEAD>

<TITLE>Fitness Center</TITLE>

</HEAD><BODY>

</BODY>

</HTML>Body.html

This document is very simple - it's empty!The body will be filled in with the HTML that

is generated by styling the XML document


Controls.html(tracing through the actions that occur when a user selects "ShowGoldMembers")

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Press Show Gold Members button

Load ShowGoldMembers.xsl

Invoke the Javascript function, ShowGoldMembers()

Transform (the previously loaded) FitnessCenter.xml

using ShowGoldMembers.xsl

Set the body of Body.html to the generated html


Controls.html(code to ShowGoldMembers)

<FORM name="controlForm"><INPUT type "button" value "Show Gold Members" onclick "ShowGoldMembers

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<INPUT type= button value= Show Gold Members onclick= ShowGoldMembers

</FORM>

<SCRIPT language="JScript" defer="true">var xml = new ActiveXObject("Msxml2.DOMDocument.3.0");

xml.async = false;

xml.load("FitnessCenter.xml");

function ShowGoldMembers()

{

var xsl = new ActiveXObject("Msxml2.DOMDocument.3.0");

xsl.async = false;

xsl.load("ShowGoldMembers.xsl");

parent.bodyFrame.document.body.innerHTML = xml.transformNode(xsl);

}

</SCRIPT>

This is preloading

the XML document

Load the XSL

document

Transform the XML

document using the

stylesheet, and assign

the body of Body.html

to the generated html.


Using SAXON in a Browser(rather the XSL Processor built into IE)

The last example utilized the XSL Processor built into IE (msxml) to do the

transformations.

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transformations. Suppose the you would like to use a different XSL Processor, e.g., SAXON?

• Why would you want to do this? Answer: SAXON has several capabilities thatmsxml does not have.

SAXON comes with a Java applet that you can use to do XSL processingwithin a browser.

See html-example-24-a for details on how to use SAXON's Java applet to

implement the multi-button example. See html-example-24-b for an example of how to use SAXON as the XSL

Processor within a browser.


Inserting spaces into HTML output

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<xsl:text disable-output-escaping="yes"><![CDATA[ ]]></xsl:text>

Put one character

references for each

space required


Debugging your Stylesheets usingxsl:message xsl:message is used to display a message, and

(optionally) terminate execution of the stylesheet

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(optionally) terminate execution of the stylesheet.

The message is sent to the screen, not to the output file.

This provides a very nice way to monitor the flow of yourstylesheet, without impacting the output file.


Example using xsl:message

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version="1.0">



<HTML>

<BODY>

<xsl:for-each select="FitnessCenter/Member">

<xsl:if test="MembershipFee < 0">

<xsl:message terminate="yes"><xsl:text>Invalid MembershipFee</xsl:text>

</xsl:message>

</xsl:if></xsl:for-each>

<xsl:text>All the MembershipFee elements are valid</xsl:text>

</BODY>

</HTML>

</xsl:template>

</xsl:stylesheet>

Two possible values for

terminate - yes, or no.

terminate="yes" means that yo

want the message output to thescreen and then the program

stopped.

terminate="no" means that you

want the message output to the

screen and the program to

continue executing.

See html-example26


system-property() function

The system-property(property name ) function enables you

to obtain information about the XSL Processor that you are

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to obtain information about the XSL Processor that you areusing:

• xsl:vendor - if you specify this as the value for property name then

it will return the name of the XSL Processor vendor

• xsl:vendor - this provides the URL to the vendor's web site

• xsl:version - this indicates what version of the XSL spec is

implemented.


Recommended Practice

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version="1.0">



<xsl:message>XSLT Processor: <xsl:value-of select="system-property('xsl:vendor')"/>

</xsl:message><HTML>

<HEAD><TITLE>Welcome</TITLE>

</HEAD>

<BODY>

Welcome!

</BODY>


</xsl:stylesheet>

It is very good practice to add this to the

start of every stylesheet. This will give

you a message indicating which XSL

Processor you are using.

When might you be uncertain which XSL

Processor is being used? Java comes

bundled with xalan. Suppose that you

want to write a Java program whichuses Saxon instead. You will definitely

want to use the above to ensure that you

are invoking Saxon and not the built-in

xalan. (I know. I have made the mistake

of thinking that I was using Saxon when

in fact I was using xalan.)

See html-example27


Embedded Stylesheets

You can embed a stylesheet within an XML document.

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<!DOCTYPE FitnessCenter [

<!ATTLIST xsl:stylesheet id ID #REQUIRED>

]>

<?xml-stylesheet type="text/xml" href="#embed"?><FitnessCenter>


<Name>Jeff</Name>


<Phone type="work">555-4321</Phone>

<FavoriteColor>lightgrey</FavoriteColor>

</Member>

...<xsl:stylesheet id="embed"

xmlns:xsl="http://www.w3.org/1999/XSL/Transform"

version="1.0">

...

</xsl:stylesheet>

</FitnessCenter>

Stylesheet embedded within

the XML document


Embedded Stylesheets

<?xml version="1 0"?>

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<?xml version= 1.0 ?>

<!DOCTYPE FitnessCenter [

<!ATTLIST xsl:stylesheet id ID #REQUIRED>]>

<?xml-stylesheet type="text/xml" href="#embed"?><FitnessCenter>


<Name>Jeff</Name>


<Phone type="work">555-4321</Phone>

<FavoriteColor>lightgrey</FavoriteColor></Member>

...

<xsl:stylesheet id="embed"xmlns:xsl="http://www.w3.org/1999/XSL/Transform"

version="1.0">

...

</xsl:stylesheet>

</FitnessCenter>

Add an id attribute to the

xsl:stylesheet element.

The stylesheet PI referencesthe embeded stylesheet (as

indicated by the"#" sign)

You must indicate

that the id attribute

is of type ID.

See html-example28 (Note: not all XSL Processors support embedded stylesheets)


Info

Course name:

Special Selected Topic in

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Special Selected Topic in

Information System Section: XSLT

Number of slides: 106

Updated date: 12/02/2006

Contact: Mr.Phan Vo Minh Thang

([email protected])