When XSLT for-each is in a loop. How can I add an attribute or node to that XML based on other XML value. USING XSLT

Question

Can any one help me to sort this problem?

I have an XML and filtering the values based on some condition. Storing the filtered xml in a variable. While filtering the condition, I'm trying to add an attribute or node to the filtered xml but it is not working for me..

Input XML:

    <root>
        <a id="13">
            <b>XXX1</b>
            <c>YYY1</c>
        </a>
        <a id="2">
            <b>XXX2</b>
            <c>YYY2</c>
        </a>
        <a id="15">
            <b>XXX3</b>
            <c>YYY3</c>
        </a>
        <a id="37">
            <b>XXX4</b>
            <c>YYY4</c>
        </a>
        <a id="51">
            <b>XXX5</b>
            <c>YYY5</c>
        </a>
    </root>

Another XML which is stored in a variable called "data" (this is for filtering):

<sample>
    <con id="37" order="1"/>
    <con id="13" order="2"/>
    <con id="51" order="3"/>
    <con id="2" order="4"/>
    <con id="15" order="5"/>
</sample>

Using XSLT, I'm trying to filter & add a element in this way.

<xsl:variable name="filteredData">
    <newroot>
      <xsl:for-each select="/root/a[@id > 14]">
        <xsl:if test="msxsl:node-set($data)/sample/con[@id = current()/@id]/@id = current()/@id">
          <xsl:element name="order">
            <xsl:value-of select="msxsl:node-set($data)/sample/con[@id = current()/@id]/@order"/>
          </xsl:element>
        </xsl:if>
      </xsl:for-each>
    </newroot>
</xsl:variable>

OUTPUT XML (i.e., "filteredData" variable should contain below XML):

     <newroot>
        <a id="15">
            <b>XXX3</b>
            <c>YYY3</c>
            <order>5</order>
        </a>
        <a id="37">
            <b>XXX4</b>
            <c>YYY4</c>
            <order>1</order>
        </a>
        <a id="51">
            <b>XXX5</b>
            <c>YYY5</c>
            <order>3</order>
        </a>
    </newroot>

Answer 1

Try using a lookup table with the key function as in this example Tip: XSLT Lookup Table

I was able to get the following snippet to produce an xml document which matched your output above. The filtering data in the xslt below has been loaded from a separate document but it should be easy to adapt.

<xsl:key name="id-lookup" match="con" use="@id"/>

<xsl:variable name="id-top" select="document('<lookup file>')/sample"/>

<xsl:template match="root">
    <newroot>
        <xsl:for-each select="a[@id > 14]">
            <xsl:copy>
                <xsl:copy-of select="@*|node()"/>

                <xsl:element name="order">
                    <xsl:apply-templates select="$id-top">
                        <xsl:with-param name="curr-label" select="."/>
                    </xsl:apply-templates>
                </xsl:element>
            </xsl:copy>
        </xsl:for-each>
    </newroot>
</xsl:template>


<xsl:template match="sample">
    <xsl:param name="curr-label"/>
    <xsl:value-of select="key('id-lookup', $curr-label/@id)/@order"/>
</xsl:template>