Extracting Subset of XML

[smyles]

Hi, I've run into a problem when trying to extract a subset of a large XML based on a reference file.

- The large XML format cannot change
- The reference file can be in whatever format (i'm creating this)

What I want to do is extract the relevant pieces from the large XML file and output this in the same format in a smaller XML file.

Below is the source XML:

Code: Select all

<?xml version="1.0" encoding="UTF-8"?>

<database>

    <record type="a">

        <value name="1"/>

        <value name="2"/>

        <value name="3"/>

        <value name="4"/>

        <value name="5"/>

        <value name="6"/>

        <value name="7"/>

        <value name="8"/>

        <value name="9"/>

        <value name="10"/>

    </record>

    <record type="b">

        <value name="1"/>

        <value name="2"/>

        <value name="3"/>

        <value name="4"/>

        <value name="5"/>

        <value name="6"/>

        <value name="7"/>

        <value name="8"/>

        <value name="9"/>

        <value name="10"/>

    </record>

    <record type="c">

        <value name="1"/>

        <value name="2"/>

        <value name="3"/>

        <value name="4"/>

        <value name="5"/>

        <value name="6"/>

        <value name="7"/>

        <value name="8"/>

        <value name="9"/>

        <value name="10"/>

    </record>

    <record type="d">

        <value name="1"/>

        <value name="2"/>

        <value name="3"/>

        <value name="4"/>

        <value name="5"/>

        <value name="6"/>

        <value name="7"/>

        <value name="8"/>

        <value name="9"/>

        <value name="10"/>

    </record>

</database>

The reference file I have is another XML, in it I enumerate bits I need from each section:

Code: Select all

<?xml version="1.0" encoding="UTF-8"?>

<record>

    <index type="a">

        <values>

            <value>1</value>

            <value>2</value>

            <value>3</value>

        </values>

    </index>

    <index type="c">

        <values>

            <value>1</value>

            <value>3</value>

            <value>6</value>

            <value>7</value>

        </values>

    </index>

    <index type="d">

        <values>

            <value>2</value>

            <value>3</value>

        </values>

    </index>

</record>

The following is the stylesheet I have tried so far, which is not working..

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<?xml version="1.0" encoding="UTF-8"?>

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">

    <xsl:output method="xml" indent="yes"/>

    <xsl:template match="/">

        <record>

            <record-indices>

                <xsl:for-each select="document('Test_Reference.xml')/record/index">

                     <xsl:variable name="first" select="."/>

                    <xsl:for-each select="//database/record">

                        <xsl:variable name="second" select="."/>

                        <xsl:if test="$first/@type=$second/@type">

                            <record-index type="{$second/@type}"/>

                        </xsl:if>

                    </xsl:for-each>

                </xsl:for-each>

            </record-indices>

        </record>

    </xsl:template>

</xsl:stylesheet>

What I've found is that if I nest the for-each with the document() function inside the the other one that I get the output I need, but I then cannot extract only the children elements I need for each of the index types, which is why I need to nest this way.

I'm pretty new to xslt so there may be a basic principal I'm missing. Any advice would be greatly appreciated.

...if there's something that I haven't explained properly just ask. I know that it makes complete sense in my head what I want to do but that might not translate to paper!!!

[smyles]

Is this actually a particularly difficult issue or am I making some fundamental mistake?