Recusion in XSL with nested XML

[oooooo0000000]

I have an XML file of varying nesting depth...

<catalouge>
<item id="1">
<name/>
<item id="23">
<name/>
<item id="55">
<name/>
</item>
</item>
<item id="7">
<name/>
</item>
</catalouge>

So, each item can contain many items.

I'm trying to get my XSLT to recursivly loop through each item to print it out in block quotes eg 1 name 23 name 55 name 7 name

How can I get a <xsl:for-each> loop to go through the whole tree?

Thanks

Yours, in confusion

o0

 

[Johannes Koch]

I have an XML file of varying nesting depth...

<catalouge>
<item id="1">
<name/>
<item id="23">
<name/>
<item id="55">
<name/>
</item>
</item>
<item id="7">
<name/>
</item>
</catalouge>

So, each item can contain many items.

I'm trying to get my XSLT to recursivly loop through each item to print it out in block quotes eg

I hope you don't mean the HTML blockquote element, which is semantically most probably inappropriate for this purpose (as the name says, it's for a long block of quotation). Nested lists (ol/ul) would be much better. If you want to indent text, use CSS.

 

[Marrow (2)]

Hi,

Whenever you are dealing with common elements that appear at nested levels it is usually best to avoid for-each and go for a recursive push approach using applied templates, e.g....

<?xml version="1.0"?>
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> <xslutput method="html" indent="yes"/> <xsl:template match="catalouge"> <html> <body> <xsl:apply-templates select="item"/> </body> </html> </xsl:template>

<xsl:template match="item">
<blockquote>
<xsl:value-of select="@id"/>
<xsl:text> </xsl:text>
<xsl:value-of select="name"/>
<xsl:apply-templates select="item"/>
</blockquote>
</xsl:template>
</xsl:stylesheet>

HTH
Marrow
http://www.marrowsoft.com - home of Xselerator (XSLT IDE and debugger) http://www.topxml.com/Xselerator

 

[Robin Johnson]

I have an XML file of varying nesting depth...

<catalouge>
<item id="1">
<name/>
<item id="23">
<name/>
<item id="55">
<name/>
</item>
</item>
<item id="7">
<name/>
</item>
</catalouge>

So, each item can contain many items.

I'm trying to get my XSLT to recursivly loop through each item to print it out in block quotes eg 1 name 23 name 55 name 7 name

How can I get a <xsl:for-each> loop to go through the whole tree?

Easy; don't. Use apply-templates. If you make this a general habit you will write much more efficient code. I think this does it in 1.0:

(A quick hack, and untested; there is probably a more efficient way even if it works, but you get the idea.)

<xsl:template match="item">
<xsl:apply-templates select="*">
</xsl:template>

<!-- if you're doing what I think you're doing (?) -->
<xsl:template match="item/*[not(self::item)]">
<!--
one of the few occasions I'll use for-each,
and even then I'd be more inclined to use a 'repeat'
subtemplate with count(ancestor::item) supplied as a parameter
-->
<xsl:for-each select="ancestor::item">
<xsl:text> </xsl:text>
</xsl:for-each>

<xsl:value-of select="concat(parent::item/@id, ' ', name)"/> <xsl:text> </xsl:text><!-- output an EOL character - I hate breaking indent style to do that, so I usually use a global text variable called $EOL or similar --> </xsl:template>

 

[oooooo0000000]

I have an XML file of varying nesting depth...

How can I get a <xsl:for-each> loop to go through the whole tree?

Ok, so I can use <xsl:for-each select="//item"> to pick up all of the items (hurrah!) and I can use other XPATHs to get all the children of a particular node.

But, how do I go about "unbalancing" the blockquotes?

I want

parent
child
grandchild
other child

etc. so I tried to use

<xsl:template match="/">
<xsl:for-each select="//item">
<BLOCKQUOTE>
<xsl:value-of select="title"/>
</xsl:for-each>
</BLOCKQUOTE>
</xsl:template>

and, of course, with the tags out of order it doesn't work. My brain is telling me I'm missing something staggeringly obvious... any clues?

Thank

o0

 

[kahrs]

Hello,

it is interesting to see that you are talking
about recursion although such XML structures
are just ordinary trees. Below you find a non-
recursive solution.

I'm trying to get my XSLT to recursivly loop through each item to print it out in block quotes eg 1 name 23 name 55 name 7 name

You asked for a solution in XSL.
I hope you wont flame me if I post a solution
in a different language. This is a GNU AWK
script which I have tested:

BEGIN { XMLMODE=1 }
XMLSTARTELEM { Depth++ }
XMLSTARTELEM == "item" { id=XMLATTR["id"] }
XMLSTARTELEM == "name" { printf("%*s %s\n", 2*Depth, id, "name" ) } XMLENDELEM { Depth-- }

As I said, this one is tested and works, producing
correctly indented lines:

1 name
23 name
55 name
7 name

How can I get a <xsl:for-each> loop to go through the whole tree?

In AWK, traversing the tree is the default behavior,
therefore no recursion is needed.

 

[Marrow (2)]

Errrrmmm, don't use for-each to begin with?

(oooooo0000000) wrote:

Ok, so I can use <xsl:for-each select="//item"> to pick up all of the items (hurrah!) and I can use other XPATHs to get all the children of a particular node.

But, how do I go about "unbalancing" the blockquotes?

I want

parent
child
grandchild
other child

etc. so I tried to use

<xsl:template match="/">
<xsl:for-each select="//item">
<BLOCKQUOTE>
<xsl:value-of select="title"/>
</xsl:for-each>
</BLOCKQUOTE>
</xsl:template>

and, of course, with the tags out of order it doesn't work. My brain is telling me I'm missing something staggeringly obvious... any clues?

Thank

o0

 

[William Park]

I have an XML file of varying nesting depth...

<catalouge>
<item id="1">
<name/>
<item id="23">
<name/>
<item id="55">
<name/>
</item>
</item>
<item id="7">
<name/>
</item>
</catalouge>

So, each item can contain many items.

I'm trying to get my XSLT to recursivly loop through each item to print it out in block quotes eg 1 name 23 name 55 name 7 name

How can I get a <xsl:for-each> loop to go through the whole tree?

Thanks

You've been given other answers. If you're adventurous, here is Bash shell solution.

start {
case $1 in
item) declare "$@"; itemid=$id ;;
name) printf "%*c %s name\n" $XML_ELEMENT_DEPTH ' ' $itemid ;; esac } xml -s start "<catalouge>...</catalouge>"

Ref:
man 3 printf
http://freshmeat.net/projects/bashdiff/
help xml