Nest elements

carlosaml · October 11th, 2007, 12:23 PM

Hi all

I'm a noob in XSLT and I need help for doing something...

I have a XML like this:

Code:

<country name="Test">
    <page id="a">
        <banner id="1">
        </banner>
    </page>
    <page id="b">
        <banner id="1">
        </banner>
    </page>
</country>
<attribute banner_id="1" name="description">This is a test</attribute>
<attribute banner_id="1" name="url">This is an URL</attribute>

What I need to is to "nest" the <attribute>'s elements to every banner that matches the ID, and then delete all the <attribute>'s that are not nested... The resulting XML must be like this:

Code:

<country name="Test">
    <page id="a">
        <banner id="1">
            <attribute banner_id="1" name="description">This is a test</attribute>
            <attribute banner_id="1" name="url">This is an URL</attribute>
        </banner>
    </page>
    <page id="b">
        <banner id="1">
            <attribute banner_id="1" name="description">This is a test</attribute>
            <attribute banner_id="1" name="url">This is an URL</attribute>
        </banner>
    </page>
</country>

I can have the same many times spread in many different pages, but I'll have the banner attrributes only once, in the of my XML...

Thanks!

joefawcett · October 11th, 2007, 01:02 PM

Assuming you have a surrounding document element, countries perhaps then you can use the identity template. Add an empty xsl:template for countries/attribute, this will get rid of the attribute elements, then add a template to process the banner elements:

Code:

<countries><country name="Test">
  <page id="a">
    <banner id="1">
    </banner>
  </page>
  <page id="b">
    <banner id="1">
    </banner>
  </page>
</country>
<attribute banner_id="1" name="description">This is a test</attribute>
<attribute banner_id="1" name="url">This is an URL</attribute>
</countries>


<?xml version="1.0" encoding="UTF-8" ?>
<xsl:stylesheet version="1.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:template match="@*|node()">
    <xsl:copy>
      <xsl:apply-templates select="@*|node()"/>
    </xsl:copy>
  </xsl:template>

  <xsl:template match="banner">
    <banner id="{@id}">
      <xsl:copy-of select="/countries/attribute[@banner_id = current()/@id]" />
    </banner>    
  </xsl:template>

  <xsl:template match="countries/attribute" />
</xsl:stylesheet>

--

Joe (Microsoft MVP - XML)

carlosaml · October 11th, 2007, 01:55 PM

Hmmm... Thanks... I'm trying to test this solution, but my machine is so slow, and my XML has 13MB approximately... o.O

Another thing... Is it possible to remove the banner_id from <attribute> when it is moved? After all, the <attribute> will be inside his banner... :)

Thank you.

mhkay · October 11th, 2007, 03:07 PM

You can speed up your transformation either

(a) by using a processor such as Saxon-SA that optimizes joins, or

(b) by optimizing them "by hand" using keys.

Where you have an expression like /a/b[c=$x], change it to key('k', $x) where the key is defined as

<xsl:key name="k" match="a/b" use="c"/>

Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference

carlosaml · October 15th, 2007, 10:35 AM

Quote:

quote:Originally posted by mhkay
You can speed up your transformation either

(a) by using a processor such as Saxon-SA that optimizes joins, or

(b) by optimizing them "by hand" using keys.

Where you have an expression like /a/b[c=$x], change it to key('k', $x) where the key is defined as

<xsl:key name="k" match="a/b" use="c"/>

Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference

I've used Saxon-SA to apply the template and it worked. (But it was soooo slow).

Now I want to remove the "banner_id" attribute from copied attributes, because they will already be inside their banner in the end...

Thanks

samjudson · October 16th, 2007, 01:53 AM

Instead of <xsl:copy-of select="/countries/attribute[@banner_id = current()/@id]" /> change it too:

<xsl:apply-templates select="/countries/attribute[@banner_id = current()/@id]" mode="move"/>

Then define the identify template to copy everything over, and one to stop the banner_id being copied over:

Code:

<xsl:template match="@*|node()" mode="move">
  <xsl:copy>
    <xsl:apply-templates  select="@*|node()"/>     
  </xsl:copy>
</xsl:template>
<xsl:template match="@banner_id" mode="move" priority="2"/>

/- Sam Judson : Wrox Technical Editor -/