Aug 13 2008

Tokenizing Delimited String inside an XSL

If your requirement is to split a node value in an XML, that contains a delimited string of value, into individual items, then you have reached the right place … have a look at the example below. If you are familiar with a little bit of XML and XSL … I don’t think you would need any explanation.
Also, this example includes usage of XSL functions like xsl:call-template , xsl:substring-before, xsl:substring-after, if that’s what you are after.

XML to be transformed (food.xml):-
Assume the task is to tokenize the string delimited by comma, in the the tag “keywords”

<?xml version="1.0" encoding="ISO-8859-1"?>
<?xml-stylesheet type="text/xsl" href="food.xsl"?>
<food>
<date>July 2008</date>
<description>All about things we eat everyday</description>
<keywords>Fruits, Vegetables, Pulses, Meat, Cereals </keywords>
</food>

XSL (food.xsl):-

<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="html" encoding="utf-8" doctype-public="-//W3C//DTD XHTML 1.0 Transitional//EN" doctype-system="http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"/>
<xsl:template match="/">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title>XSL 1.0 Delimited String Tokeniser</title>
</head>
<body>
<xsl:value-of select="food/meta"/>
<div >
<xsl:call-template name="tokenize">
<xsl:with-param name="string" select="food/keywords" />
<xsl:with-param name="delimitr" select="','" />
</xsl:call-template>

</div>
</body>
</html>
</xsl:template>
<xsl:template name="tokenize">
<xsl:param name="string" />
<xsl:param name="delimitr" />
<xsl:choose>
<xsl:when test="contains($string, $delimitr)">
<div style="border:1px solid red;">
<h3><xsl:value-of select="substring-before($string,$delimitr)" /></h3>
<xsl:variable name="data" select="substring-before($string,$delimitr)"/>
</div>
<xsl:call-template name="tokenize">
<xsl:with-param name="string" select="substring-after($string, $delimitr)" /><xsl:with-param name="delimitr" select="$delimitr" /></xsl:call-template>
</xsl:when>
<xsl:otherwise>
<div style="border:1px solid red;">
<h3><xsl:value-of select="$string" /></h3>
</div>
</xsl:otherwise>
</xsl:choose>
</xsl:template>
</xsl:stylesheet>

Resultant output HTML :-

<div>
<div style="border: 1px solid red;">
<h3>Fruits</h3>
</div>
<div style="border: 1px solid red;">
<h3> Vegetables</h3>
</div>
<div style="border: 1px solid red;">
<h3> Pulses</h3>
</div>
<div style="border: 1px solid red;">
<h3> Meat</h3>
</div>
<div style="border: 1px solid red;">
<h3> Cereals </h3>
</div>
</div>

Needless to say … just change the parameter “delimitr” to the delimiter of your choice


Aug 4 2008

A problem with position() in XSL … or is it?

I had this strage problem while creating a XSL today. Looked for answers throughout the net, but couldnt find any …. Actually I guess! I dint know what my problem was, so what do I look for?

Anyway! Just in case you have this very same problem too and somehow by the power of the FORCE you managed to land on this page … you would thank me tons … And if you have accidently landed on this page for some strange fate and you happen to be a XSL developer , DO MAKE A NOTE OF THIS NOW, FOR THE FUTURE cause, If some day, you face this issue, then the FORCE might not be with you.

Problem statement:
I have this XML , where there are two nodes with multiple items in it and the items between these two nodes have a one to one correspondence. In the example below, each item in the node <array name=”PLAYURL” /> relates( corresponding position) to an item in the node <array name=”SITENAME” />

<?xml version="1.0" encoding="utf-8"?>
<myplaylists>
<playlist>
<title>Best of Rest </title>
<array name="SITENAME">
<str>www.musicindiaonline.com</str>
<str>www.dhingana.com</str>
<str>www.raaga.com</str>
<str>www.smashits.com</str>
<str>www.desimusic.com</str>
<str>www.musicplug.in</str>
</array>
<array name="PLAYURL">
<str>http://www.musicindiaonline.com/123/</str>
<str>http://www.dhingana.com/play/123</str>
<str>http://www.raaga.com/123</str>
<str>http://ww.smashits.com/123</str>
<str>http://www.desimusic.com/123</str>
<str>http://www.musicplug.in/123</str>
</array>
</playlist>
</myplaylists>

Now, I have a loop , where i loop through <array name=”SITENAME”>, and I want to get the related item( at the corresponding position) in <array name=”PLAYURL”>,

What you would normaly try do is …

<xsl:for-each select="myplaylists/playlist/array[@name='SITENAME']/str">
play from : <a href="{../../array[@name='PLAY']/str[position()]}"/> <xsl:value-of select="." /></a>
</xsl:for-each>

SORRY!! THIS WONT WORK … Ah!!!! Surpised …

Now you would probably want to try , something like this …

<xsl:for-each select="myplaylists/playlist/array[@name='SITENAME']/str">
<xsl:variable name="pos"> <xsl:value-of select="position()"/></xsl:variable>
play from : <a href="{../../array[@name='PLAY']/str[$pos]}"/> <xsl:value-of select="." /></a>
</xsl:for-each>

And Again this wont work … Now you scratching your head, trying to contact everyone who you think knows some XSL and could be of any help … you try every other option … and still it wont work … Well! Thats what happened to me atleast …

DONT DESPAIR !!! TRY THIS

<xsl:for-each select="myplaylists/playlist/array[@name='SITENAME']/str">
<xsl:variable name="pos-int" select="position()" />
play from : <a href="{../../array[@name='PLAY']/str[$
pos-int]}"/> <xsl:value-of select="." /></a>
</xsl:for-each>

DONT ASK ME WHY IT WORKS. Cause i dont have a right reason… if you do! Please do drop a comment. It might be pretty usefull. Also! if you have better TITLE for this post, do drop me a line :)


May 4 2008

Include XSL inside XSL

If XML/XSL Transforms is your domian, then there are times when we want a peice of Dynamic code to be used library item(to be made re-usable). What I mean , probably could be made more clear with this example scenario.

Imagine you are creating a website (and using XML, XSL transfroms ofcourse) and most of the pages would have a Comments Module . Well! then either you copy or paste this code into every page template (which I dont have say, but make maintenance and rework a nightmare) or even better, you create an INCLUDE file which could be pulled in where ever you want it in your page(s)…
So HOW DO WE CREATE a XSL INCLUDE file and include it inside another XSL file? Here is how…

Just to make things clear … here is quick list of files that you would create … here , we will be including info about fruits and vegetables into a parent page called food.

1. food.xml – xml data file on which the transformation will be applied
2. food.xsl  -  main XSL file, which will transform our food.xml
3. inc_fruits.xsl – XSL include file that will render fruits data
4. inc_vegtables.xsl – XSL include file that will render vetetables data

I dont think I have explain much , the codes for above elements , will be self explanatory…

FOOD.XML


<?xml version="1.0" encoding="ISO-8859-1"?>
<?xml-stylesheet type="text/xsl" href="food.xsl"?>
<food>
<date>July 2008</date>
<description>All about things we eat everyday</description>
<fruits type="tropical">
<item name="mango" moreinfo="http://www.mango.com">Mango is the king of fruits</item>
<item name="banana" moreinfo="http://www.banana.com">Banana once a day , keeps the doctor away</item>
<item name="orange" moreinfo="http://www.orange.com">Orange is the color and rich in vitamin C</item>
<item name="Papaya" moreinfo="http://www.papaya.com">Papaya - Hot when raw, cold when ripe</item>
</fruits>

<vegetables>
<item name="spinach" moreinfo="http://www.spinach.com">Spinach is full of iron</item>
<item name="asparagus" moreinfo="http://www.asparagus.com">Asparagus contains loads of vitamin D </item>
<item name="fenugreek" moreinfo="http://www.fenugreek.com">Fenugreek is rich in vitamin C</item>
</vegetables>
</food>


FOOD.XSL


<?xml version="1.0" encoding="ISO-8859-1"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:include href="inc_fruits.xsl" />
<xsl:include href="inc_vegetables.xsl" />
<xsl:template match="/">
<html>
<head>
<title>Title</title>
</head>
<body>
<h3><xsl:value-of select="/food/description" /></h3>
Modification Date : <xsl:value-of select="/food/date" />
<hr/>
<h5> About Fruits</h5>
<xsl:call-template name="about_fruits"/>

<hr/>
<h5> About Vegetables</h5>
<xsl:call-template name="about_vegetables"/>

<hr/>
</body>
</html>
</xsl:template>
</xsl:stylesheet>

 


INC_FRUITS.XSL

<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="html" encoding="iso-8859-1" />
<xsl:template name="about_fruits">
<xsl:for-each select="/food/fruits/item/@*">
attribute name : <xsl:value-of select="name()"/> 
attribute value : <xsl:value-of select="."/> <br />
</xsl:for-each>
</xsl:template>
</xsl:stylesheet>


INC_VEGETABLES.XSL

<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="html" encoding="iso-8859-1" />
<xsl:template name="about_vegetables">
<xsl:for-each select="/food/vegetables/item/@*">
attribute name : <xsl:value-of select="name()"/> 
attribute value : <xsl:value-of select="."/> <br/>
</xsl:for-each>
</xsl:template>
</xsl:stylesheet>

Download all the above files here (68 downloads)


Apr 4 2008

Working with XML Node Attributes in XSLT

If you use XML and XSL, then you might have come across a time , when you have to play around with attributes and values of XML nodes in you XSL. They are loads of sites with long winded info about this, but none I found were brief and precise … This is NO XML/XSL TUTORIAL,but my attempt to put-together some sort of cheat list …

The sample XML that we will working with looks like this…

<?xml version="1.0" encoding="ISO-8859-1"?>
<?xml-stylesheet type="text/xsl" href="food.xsl"?>
<food>
<fruits type="tropical">
<item name="mango" moreinfo="http://www.mango.com">Mango is the king of fruits</item>
<item name="banana" moreinfo="http://www.banana.com">Banana once a day , keeps the doctor away</item>
<item name="orange" moreinfo="http://www.orange.com">Orange is the color and rich in vitamin C</item>
<item name="Papaya" moreinfo="http://www.papaya.com">Papaya - Hot when raw, cold when ripe</item>
</fruits>
</food>

So Lets begin transforming our above XML using XSL

Example 1 : Displaying value at a chosen Attribute

<xsl:value-of select="/food/fruits/item[@name='orange']" /><br />
to get more information about <a href="{/food/fruits/item[@name='orange']/@moreinfo}" target="new" ><xsl:value-of select="/food/fruits/item[@name='orange']/@name" /> </a>

HTML result will look like

Orange is the color and rich in vitamin C,
to get more information about <a href="http://www.orange.com" target="new">


Example 2 : Looping through and displaying all XML Attribute Names and their Values

<xsl:for-each select="/food/fruits/item/@*">
attribute name : <xsl:value-of select="name()"/>, 
attribute value : <xsl:value-of select="."/>  <br />
</xsl:for-each>

HTML result will look like


attribute name : name, attribute value : mango
attribute name : moreinfo, attribute value : http://www.mango.com
attribute name : name, attribute value : banana
attribute name : moreinfo, attribute value : http://www.banana.com
attribute name : name, attribute value : orange
attribute name : moreinfo, attribute value : http://www.orange.com
attribute name : name, attribute value : Papaya
attribute name : moreinfo, attribute value : http://www.papaya.com


Download all the above files here (88 downloads)



Watch this space, I’ll keep updating this with new findings…


 
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