Expressing IT » XSL http://developer.expressionz.in/blogs User Interface : just another, but a serious developers weblog Thu, 20 May 2010 18:05:48 +0000 http://wordpress.org/?v=2.9.2 en hourly 1 A problem with position() in XSL … or is it? http://developer.expressionz.in/blogs/2008/08/04/problem-with-position-in-xsl/ http://developer.expressionz.in/blogs/2008/08/04/problem-with-position-in-xsl/#comments Mon, 04 Aug 2008 13:33:59 +0000 Nikhil http://developer.expressionz.in/blogs/?p=17

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 :)

]]> http://developer.expressionz.in/blogs/2008/08/04/problem-with-position-in-xsl/feed/ 0 Setting the DOCTYPE in XSL http://developer.expressionz.in/blogs/2008/08/02/setting-the-doctype-in-xsl/ http://developer.expressionz.in/blogs/2008/08/02/setting-the-doctype-in-xsl/#comments Sun, 03 Aug 2008 05:28:33 +0000 Nikhil http://developer.expressionz.in/blogs/?p=14

Last week I created a progessive HTML/CSS layout for a client, tested it in IE6, IE7 and FF 3, seemed perfectly fine… UNTIL! the layout went further down the manufacting cycle. It failed. Page layout elements just went all over the place when the HTML layout was converted into  XSL and  XML applied to it … Bummer!!!

Could not sleep ok over the weekend, in anticipation of Monday morning, when I’ll have to fix this SH**. But now having a little experince in dealing with these kind of situations ( Browser Quirks, I mean), I knew it had to do with nothing else but DOCTYPE…. and It WAS…

The Problem:
You want control over the DOCTYPE, since your transformation will include a default DOCTYPE explicitly, and you layout will be out for a toss.

The Solution:
XSLT specs provides output methods to set a the DOCTYPE of choise. Also, for us UI developers, the topics of interest would be HTML output methods and XML output methods.

Well! before you get bored , here is the fix.

For eg., if you had the following DOCTYPE in your HTML version :-

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

Then in the XSL you would have to have the following :-

<xsl:output method="html" doctype-system="http://www.w3.org/TR/html4/loose.dtd" doctype-public="-//W3C//DTD HTML 4.01 Transitional//EN" indent="yes" />

and Finally! do make sure your XSLT output obeys the DOCTYPE  you have chosen.

]]> http://developer.expressionz.in/blogs/2008/08/02/setting-the-doctype-in-xsl/feed/ 1 Include XSL inside XSL http://developer.expressionz.in/blogs/2008/05/04/include-xsl-inside-xsl/ http://developer.expressionz.in/blogs/2008/05/04/include-xsl-inside-xsl/#comments Sun, 04 May 2008 09:48:51 +0000 Nikhil http://developer.expressionz.in/blogs/?p=16 Comments Module . Well! then either you copy or paste this code into every page template or even better you create an INCLUDE file can call it where ever you want it in your main page template...So HOW DO WE INCLUDE a XSL file inside another XSL file? Here is how...]]>

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 (88 downloads)

]]> http://developer.expressionz.in/blogs/2008/05/04/include-xsl-inside-xsl/feed/ 0 Working with XML Node Attributes in XSLT http://developer.expressionz.in/blogs/2008/04/04/working-with-xml-node-attributes-in-xslt/ http://developer.expressionz.in/blogs/2008/04/04/working-with-xml-node-attributes-in-xslt/#comments Fri, 04 Apr 2008 08:17:25 +0000 Nikhil http://developer.expressionz.in/blogs/?p=15

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 (111 downloads)



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

]]> http://developer.expressionz.in/blogs/2008/04/04/working-with-xml-node-attributes-in-xslt/feed/ 0