XSL Unit 6 November 2
Download
Report
Transcript XSL Unit 6 November 2
XSL
Unit 6
November 2
XSL
• XSL
– eXtensible Stylesheet Language
– Basically a stylesheet for XML documents
• XSL has three parts:
– XSLT
– XPath
– XSL-FO
XSLT
• The most important bit of XSL
• XSLT allows us to transform an XML
document into another XML document
– For instance, transform an XML document
into an XHTML document
• XSLT relies on using XPath
– We’re going to use it, but not cover it
– Don’t have to go into detail in order to create
simple, effective XSL documents
XSLT Basics
• The whole idea behind XSLT is template
matching
• What’s a template?
– Let’s say we have a list of students like what we’ve
done in class:
<student>
<firstName>Marky</firstName>
<lastName>Mark</lastName>
<studentNumber>2001-22222</studentNumber>
</student>
Templates, cont.
• We know what one student “looks” like
• All students follow the same format:
Student:
first name
last name
student number
• Every single one of the students in our XML
document are described in exactly the same
manner
• We can use a template to identify and use the
parts of each student
Templates, cont.
<studentList>
<student>
<firstName>Marky </firstName>
<lastName>Mark </lastName>
<studentNumber>200122222 </lastname>
</student>
<student>
<firstName>Selma </firstName>
<lastName>Blair </lastName>
<studentNumber>200133333 </lastname>
</student>
……
</studentList>
Creating a New XSL Stylesheet
• Created with a text editor
• Saved with file extension “.xsl”
• Just like with HTML, we have to put some
“bits” at the top of our XSL file
• Again, you do not have to have these
memorized completely
– I will provide a blank version online when/if
needed
Creating an XSL Stylesheet, cont.
<?xml version="1.0" encoding="ISO-8859-1"?>
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
Or
<?xml version="1.0" encoding="ISO-8859-1"?>
<xsl:transform version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
• You can use either “xls:stylesheet” or “xls:transform”, they are
identical
Linking the XSL file to the XML file
• The top of our XML file should read
something like this:
<?xml version="1.0" encoding="ISO-8859-1"?>
<?xml-stylesheet type="text/xsl"
href=“studentlist.xsl"?>
• This is nearly identical to how we link HTML
pages to CSS files
• Again, an empty file will be provided for you if
needed
– But! You do need to know how to link to an XSL file
xsl:template
• xsl:template is an XSL element
• We are going to use it to apply rules when
the template match is found
• <xsl:template match = “/”>
– match = “/” means that we’ll apply the
template to the entire XML document
• This is the next line of our XSL file
XSL File, so far
<?xml version="1.0" encoding="ISO-8859-1"?>
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match = “/”>
……….
</xsl:template>
</xsl:stylesheet>
Beginning the Transformation to
HTML
• What do we need for an html file?
– <html>
– <body>
– Maybe a <head> tag?
• This is what we’ll add next to our XSL file
Beginning HTML
<?xml version="1.0" encoding="ISO-8859-1"?>
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match = “/”>
<html>
<head><title>XML Example</title></head>
<body>
……….
</body>
</html>
</xsl:template>
</xsl:stylesheet>
In-Class Example
• Adding some HTML
How do we add data?
• <xsl:value-of> gives us the value of a certain bit of our
xml file
• Which bit?
– We’ll use the select property and the information about our tag
• <xsl:value-of select =“studentList/student/first_name”/>
• This long value for select is based on the structure of our
XML document
–
–
–
–
<studentList> is our root element
<student> is contained within <studentList>
<first_name> is the data we’re interested in
Just like paths for URLs
In class Example
• Adding some data to our html
• Using more html tags
More than Student?
• We can get the data for a single student,
but what about our list of 3 students?
– Or 300 for that matter?
– We don’t want to cut and paste for every
student
• What if the number of students changes?
• We can use the <xsl:for-each> element to
loop through each of our students
– Can use it to look through any “sets” of data
nodes (think items with (+) marks)
Using <xsl:for-each>
• <xsl:for-each> requires the use of the select
attribute
• <xsl:for-each select = “some expression”>
• But what to use?
– Depends on the repeat of the data
– In the case of having a list of students
• select = “studentList/student”
• Basically you can read this as “for each student, apply these
rules below”
• <xsl:for-each select=“studentList/student”>
In Class Example
• Adding for-each to loop through the
students in the XML document
• Reversing last and first name
• Changing the format of the data
Sorting the Data
• We can sort the data in our XML files
– For instance, we can alphabetize our student
list
– Even if it’s not alphabetical in the XML file, the
HTML output will have the items in
alphabetical order
• We are going to use the element
<xsl:sort>
Using <xsl:sort>
• We can specify what we are sorting on
– First name?
– Last name?
– <xsl:sort select=“last_name”>
• Default is to sort ascending (A, B…Z)
– But we can reverse it by using the order
property:
<xsl:sort select=“last_name” order=“descending”/>
In Class Example
• Sorting the student list ascending and
descending
– Using both first and last name
• Another XML file with products
Questions?