XSLT how to remove unwanted output - xslt

Question

I have an xsl stylesheet giving just about what is needed, except there are values outputted outside the tags, . Is there a way to remove them? The scenario is that the desired output is a total invoice amount for invoices that appear more than once. Each time the xslt is executed the parameter p1 contains the InvoiceNumber to total. The code below shows that parameter, p1, hardcoded to '351510'.
<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output omit-xml-declaration="yes" indent="yes"/>
<xsl:strip-space elements="*"/>
<xsl:template match="/Invoices/Invoice[InvoiceNumber=351510][1]/InvoiceNumber">
<xsl:copy>
<xsl:apply-templates select="/Invoices/Invoice[InvoiceNumber=351510][1]/InvoiceAmount"/>
</xsl:copy>
</xsl:template>
<xsl:param name="tempvar"/>
<xsl:template name="InvTotal" match="/Invoices/Invoice[InvoiceNumber=351510][1]/InvoiceNumber">
<xsl:variable name="p1" select="351510" />
<xsl:if test="/Invoices/Invoice/InvoiceNumber[. = $p1]">
<!--<xsl:if test="$test = $p1" >-->
<InvoiceAmount>
<xsl:value-of select="sum(../../Invoice[InvoiceNumber=351510]/InvoiceAmount)"/>
</InvoiceAmount>
</xsl:if>
</xsl:template>
</xsl:stylesheet>
Here is the input:
<Invoices>
- <Invoice>
<InvoiceNumber>351510</InvoiceNumber>
<InvoiceAmount>137.00</InvoiceAmount>
</Invoice>
- <Invoice>
<InvoiceNumber>351510</InvoiceNumber>
<InvoiceAmount>363.00</InvoiceAmount>
</Invoice>
- <Invoice>
<InvoiceNumber>351511</InvoiceNumber>
<InvoiceAmount>239.50</InvoiceAmount>
</Invoice>
</Invoices>
Here is the output:
<InvoiceAmount>500</InvoiceAmount>137.00351510363.00351511239.50
Here is desired output:
<InvoiceAmount>500</InvoiceAmount>
Also, thank you goes to lwburk who got me this far.

Answer 1

Adding
<xsl:template match="text()"/>
should help.

Answer 2

I do not get the same results as you posted (only 351510137.00351510363.00351511239.50, all the text nodes), and I do not know the purpose of tempvar (unused).
Since it appears that all you need is the sum of InvoiceAmount values for a specific InvoiceNumber, just keep it simple and ignore everything else:
<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output omit-xml-declaration="yes" indent="yes"/>
<xsl:param name="invoiceNumber"/>
<xsl:template match="/">
<InvoiceAmount>
<xsl:value-of select="sum(/Invoices/Invoice[InvoiceNumber=$invoiceNumber]/InvoiceAmount)"/>
</InvoiceAmount>
</xsl:template>
</xsl:stylesheet>
You can pass the InvoiceNumber to process via the parameter invoiceNumber, or you can hardcode it if you like (see version 1).
Note: should you prefer a number format like e.g. #.00 (fixed decimals) for the sum, then you can also use the format-number(…) function.

Answer 3

This transformation:
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output omit-xml-declaration="yes" indent="yes"/>
<xsl:strip-space elements="*"/>
<xsl:param name="pNum" select="351510"/>
<xsl:key name="kInvAmmtByNumber" match="InvoiceAmount"
use="../InvoiceNumber"/>
<xsl:variable name="vInvoiceAmounts" select=
"key('kInvAmmtByNumber', $pNum)"/>
<xsl:variable name="vIdInvAmount1" select=
"generate-id($vInvoiceAmounts[1])"/>
<xsl:template match="InvoiceAmount">
<xsl:if test="generate-id() = $vIdInvAmount1">
<InvoiceAmount>
<xsl:value-of select="sum($vInvoiceAmounts)"/>
</InvoiceAmount>
</xsl:if>
</xsl:template>
<xsl:template match="text()"/>
</xsl:stylesheet>
when applied on the provided XML file:
<Invoices>
<Invoice>
<InvoiceNumber>351510</InvoiceNumber>
<InvoiceAmount>137.50</InvoiceAmount>
</Invoice>
<Invoice>
<InvoiceNumber>351510</InvoiceNumber>
<InvoiceAmount>362.50</InvoiceAmount>
</Invoice>
<Invoice>
<InvoiceNumber>351511</InvoiceNumber>
<InvoiceAmount>239.50</InvoiceAmount>
</Invoice>
</Invoices>
produces exactly the wanted, correct result:
<InvoiceAmount>500</InvoiceAmount>
Explanation:
The wanted invoice number is passed to the transformation as the value of the external/global parameter $pNum .
We use a key that indexes all InvoiceAmount elements by their corresponding InvoiceNumber values.
Using that key we define the variable $vInvoiceAmounts that contains the node-set of all InvoiceAmount elements the value of whose corresponding InvoiceNumber element is the same as the value of the external parameter $pNum.
We also define a variable ($vIdInvAmount1) that contains a unique Id of the first such InvoiceAmount element.
There is a template that matches any InvoiceAmount element. It checks if the matched element is the first of the elements contained in the node-set $vInvoiceAmounts. If so, a InvoiceAmount element is generated with a single text-node child, whose value is the sum of all InvoiceAmount elements contained in $vInvoiceAmounts. Otherwise nothing is done.
Finally, there is a second template that matches any text node and does nothing (deletes it in the output), effectively overriding the unwanted side effect of the default XSLT processing -- the outputting of unwanted text.