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[XSL-LIST Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] Re: XSLT repetition constructs comparison
 I would personally only use xsl:iterate where you need something that
xsl:for-each can't do, such as early exit, or accumulation of parameter
values. But an xsl:iterate with no parameters, no xsl:break, no
xsl:on-completion is equivalent to xsl:for-each so there's no intrinsic reason
to prefer one over the other. There may be implementation differences but
that's processor-specific.
If you need some of the features of xsl:iterate and also want sorting, then I
would normally use the sort() function:
<xsl:iterate select="sort(student, (), function($s){$s/(fName, lName))">...
or if that's not possible (e.g because you need a descending sort), then sort
first (into a variable) using xsl:perform-sort.
Michael Kay
Saxonica
> On 14 Jan 2021, at 09:05, Mukul Gandhi mukulg@xxxxxxxxxxxxxxxxx
<xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hi all,
> I'm comparing the functionality of, XSLT repetition constructs
xsl:for-each and xsl:iterate (versions 2.0 & 3.0). Below is my example use
case, and the corresponding XSLT solutions from my side,
>
> XML input document:
>
> <?xml version="1.0"?>
> <students>
> <student>
> <rollNo>1</rollNo>
> <fName>Sharon</fName>
> <lName>Adler</lName>
> </student>
> <student>
> <rollNo>2</rollNo>
> <fName>Anders</fName>
> <lName>Berglund</lName>
> </student>
> <student>
> <rollNo>3</rollNo>
> <fName>Norm</fName>
> <lName>Walsh</lName>
> </student>
> <student>
> <rollNo>4</rollNo>
> <fName>Michael</fName>
> <lName>Sperberg-McQueen</lName>
> </student>
> <student>
> <rollNo>5</rollNo>
> <fName>Florent</fName>
> <lName>Georges</lName>
> </student>
> </students>
>
> I wish to transform, the above XML data into HTML, using XSLT. The resulting
HTML, needs to have a table containing rows representing each XML input
"student" element, and a total record count at the bottom of HTML output.
>
> Below are my various XSLT solutions,
>
> (1) An XSLT 2.0 solution, with sorting (sorting by fName & lName):
>
> <?xml version="1.0"?>
> <xsl:stylesheet version="2.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform
<http://www.w3.org/1999/XSL/Transform>">
>
> <xsl:output method="html" indent="yes"/>
>
> <xsl:template match="students">
> <html>
> <head>
> <title>Student list</title>
> </head>
> <body>
> <table>
> <tr>
> <td><b>Roll No.</b></td>
> <td><b>First name</b></td>
> <td><b>Last name</b></td>
> </tr>
> <xsl:for-each select="student">
> <xsl:sort select="fName"/>
> <xsl:sort select="lName"/>
> <tr>
> <td align="center"><xsl:value-of
select="rollNo"/>.</td>
> <td><xsl:value-of select="fName"/></td>
> <td><xsl:value-of select="lName"/></td>
> </tr>
> </xsl:for-each>
> <tr>
> <td colspan="3"> </td>
> </tr>
> <tr>
> <td colspan="2"><b>Total no of students</b> : </td>
> <td><xsl:value-of select="count(student)"/></td>
> </tr>
> </table>
> </body>
> </html>
> </xsl:template>
>
> </xsl:stylesheet>
>
> (2) An XSLT 3.0 solution, without sorting:
>
> <?xml version="1.0"?>
> <xsl:stylesheet version="3.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform
<http://www.w3.org/1999/XSL/Transform>"
>
xmlns:xs="http://www.w3.org/2001/XMLSchema
<http://www.w3.org/2001/XMLSchema>"
>
exclude-result-prefixes="xs">
>
> <xsl:output method="html" indent="yes"/>
>
> <xsl:template match="students">
> <html>
> <head>
> <title>Student list</title>
> </head>
> <body>
> <table>
> <tr>
> <td><b>Roll No.</b></td>
> <td><b>First name</b></td>
> <td><b>Last name</b></td>
> </tr>
> <xsl:iterate select="student">
> <xsl:param name="total" select="0" as="xs:integer"/>
> <xsl:on-completion>
> <tr>
> <td colspan="3"> </td>
> </tr>
> <tr>
> <td colspan="2"><b>Total no of students</b> : </td>
> <td><xsl:value-of select="$total"/></td>
> </tr>
> </xsl:on-completion>
> <tr>
> <td align="center"><xsl:value-of
select="rollNo"/>.</td>
> <td><xsl:value-of select="fName"/></td>
> <td><xsl:value-of select="lName"/></td>
> </tr>
> <xsl:next-iteration>
> <xsl:with-param name="total" select="$total + 1"/>
> </xsl:next-iteration>
> </xsl:iterate>
> </table>
> </body>
> </html>
> </xsl:template>
>
> </xsl:stylesheet>
>
> (3) An XSLT 3.0 solution, with sorting:
>
> <?xml version="1.0"?>
> <xsl:stylesheet version="3.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform
<http://www.w3.org/1999/XSL/Transform>"
>
xmlns:xs="http://www.w3.org/2001/XMLSchema
<http://www.w3.org/2001/XMLSchema>"
>
exclude-result-prefixes="xs">
>
> <xsl:output method="html" indent="yes"/>
>
> <xsl:template match="students">
> <html>
> <head>
> <title>Student list</title>
> </head>
> <body>
> <table>
> <tr>
> <td><b>Roll No.</b></td>
> <td><b>First name</b></td>
> <td><b>Last name</b></td>
> </tr>
> <xsl:variable name="result_1" as="element(tr)*">
> <xsl:iterate select="student">
> <xsl:param name="total" select="0" as="xs:integer"/>
> <xsl:on-completion>
> <tr>
> <td colspan="3"> </td>
> </tr>
> <tr>
> <td colspan="2"><b>Total no of students</b> :
</td>
> <td><xsl:value-of select="$total"/></td>
> </tr>
> </xsl:on-completion>
> <tr>
> <td align="center"><xsl:value-of
select="rollNo"/>.</td>
> <td><xsl:value-of select="fName"/></td>
> <td><xsl:value-of select="lName"/></td>
> </tr>
> <xsl:next-iteration>
> <xsl:with-param name="total" select="$total + 1"/>
> </xsl:next-iteration>
> </xsl:iterate>
> </xsl:variable>
> <xsl:perform-sort select="$result_1[position() le
(count($result_1)-2)]">
> <xsl:sort select="td[2]"/>
> <xsl:sort select="td[3]"/>
> </xsl:perform-sort>
> <xsl:copy-of select="$result_1[position() gt
(count($result_1)-2)]"/>
> </table>
> </body>
> </html>
> </xsl:template>
>
> </xsl:stylesheet>
>
> I haven't mentioned the solution, where we could use xsl:apply-templates
instead of xsl:for-each or xsl:iterate.
>
> Firstly, I find xsl:iterate much more functionally rich (except that it
doesn't provide native sorting support) than xsl:for-each, if there's a
requirement of XSLT sequential looping. If there's no requirement for sorting,
then in XSLT 3.0 environment, I'd opt to use xsl:iterate. If there's
requirement for sorting, then in XSLT 3.0 environment, I might opt to use
xsl:for-each instead of xsl:iterate (does anybody differ?). When using XSLT
3.0 xsl:iterate, with a requirement of sorting, can anyone suggest a different
(and possibly better as well) solution than (3) above?
>
> Any thoughts, about performance aspects of various XSLT solutions relevant
to this thread, would also be useful to know.
>
>
>
> --
> Regards,
> Mukul Gandhi
> XSL-List info and archive <http://www.mulberrytech.com/xsl/xsl-list>
> EasyUnsubscribe <http://lists.mulberrytech.com/unsub/xsl-list/293509> (by
email <>)
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