Best way to use for-each inside if in XSLT - xslt

Question

I have the below XML data as input to my XSLT:
<?xml version="1.0" encoding="UTF-8"?>
<Application>
<Data>
<Data1>
<name>Michale</name>
<age>65</age>
<Info>
<Alias name="M">
<Contactmail>abc#gmail.com</Contactmail>
<ContactPh>8988900009</ContactPh>
</Alias>
<Alias name="Q">
<Contactmail>abc#gmail.com</Contactmail>
<ContactPh>8988900009</ContactPh>
</Alias>
</Info>
</Data1>
<Data1>
<name>Albert</name>
<age>69</age>
<Info>
<Alias name="A">
<Contactmail>xyz#gmail.com</Contactmail>
<ContactPh>89889908709</ContactPh>
</Alias>
<Alias name="P">
<Contactmail>pqr#gmail.com</Contactmail>
<ContactPh>8988988779</ContactPh>
</Alias>
</Info>
</Data1>
</Data>
</Application>
And I want to pass the Data1 block whose Alias name matches with "M", i.e.:
<Application>
<Data>
<Data1>
<name>Michale</name>
<age>65</age>
<Info>
<Alias name=M>
<Contactmail>abc#gmail.com</Contactmail>
<ContactPh>8988900009</ContactPh>
</Alias>
<Alias name=Q>
<Contactmail>abc#gmail.com</Contactmail>
<ContactPh>8988900009</ContactPh>
</Alias>
</Info>
</Data1>
</Data>
</Application>
I am stuck as to how to access an loop(ie Alias) inside a test condition?
Is there any better way to do this xslt?
<xsl:for-each select="./*[local-name() = 'Application']/*[local-name() = 'Data']">
<xsl:if test="">
....
</xsl:if>
</xsl:for-each>

Answer 1

The following template will do the job. The explanations are in the code.
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="xml" indent="yes"/>
<xsl:strip-space elements="*" /> <!-- Removes unnecessary space between elements -->
<!-- identity template --> <!-- Copies all nodes not matched by other templates -->
<xsl:template match="node()|#*">
<xsl:copy>
<xsl:apply-templates select="node()|#*" />
</xsl:copy>
</xsl:template>
<xsl:template match="Data1[Info/Alias/#name != 'M']" /> <!-- Ignores all Data1 elements which don't have an #name='M' attribute child -->
<xsl:template match="Data1[Info/Alias/#name = 'M']"> <!-- Matches all Data1 elements which have the desired child attribute -->
<xsl:copy>
<xsl:apply-templates select="node()|#*" />
</xsl:copy>
</xsl:template>
</xsl:stylesheet>
Its output is:
<?xml version="1.0"?>
<Application>
<Data>
<Data1>
<name>Michale</name>
<age>65</age>
<Info>
<Alias name="M">
<Contactmail>abc#gmail.com</Contactmail>
<ContactPh>8988900009</ContactPh>
</Alias>
<Alias name="Q">
<Contactmail>abc#gmail.com</Contactmail>
<ContactPh>8988900009</ContactPh>
</Alias>
</Info>
</Data1>
</Data>
</Application>

Answer 2

<xsl:strip-space elements="*"/>
<xsl:template match="#*|node()">
<xsl:copy>
<xsl:apply-templates select="#*|node()"/>
</xsl:copy>
</xsl:template>
<xsl:template match="Application">
<xsl:copy>
<xsl:for-each select="Data/Data1">
<xsl:if test="Info/Alias[#name='M']">
<Data>
<Data1>
<xsl:apply-templates/>
</Data1>
</Data>
</xsl:if>
</xsl:for-each>
</xsl:copy>
</xsl:template>
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