Question

I am beginner in XSLT 1.0. I am using XSLT to transform XML to XML.
I would like to get first 5 unique Airline from the received XML.

Source XML:

<Response>
    <Flights>
        <Flight>
            <Segments>
                <Segment>
                    <Airline>AB</Airline>
                </Segment>
            </Segments>
        </Flight>
        <Flight>
            <Segments>
                <Segment>
                    <Airline>CD</Airline>
                </Segment>
            </Segments>
        </Flight>
        <Flight>
            <Segments>
                <Segment>
                    <Airline>EF</Airline>
                </Segment>
            </Segments>
        </Flight>
        <Flight>
            <Segments>
                <Segment>
                    <Airline>EF</Airline>
                </Segment>
            </Segments>
        </Flight>
        <Flight>
            <Segments>
                <Segment>
                    <Airline>EF</Airline>
                </Segment>
            </Segments>
        </Flight>
        <Flight>
            <Segments>
                <Segment>
                    <Airline>EF</Airline>
                </Segment>
            </Segments>
        </Flight>
        <Flight>
            <Segments>
                <Segment>
                    <Airline>SD</Airline>
                </Segment>
            </Segments>
        </Flight>
    </Flights>
    <OtherRecommens>
        <RecommFlight>
            <Airline>XY</Airline>
        </RecommFlight>
        <RecommFlight>
            <Airline>ZZ</Airline>
        </RecommFlight>
        <RecommFlight>
            <Airline>XY</Airline>
        </RecommFlight>
        <RecommFlight>
            <Airline>AB</Airline>
        </RecommFlight>
    </OtherRecommens>
</Response>

XSLT:

<?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="Response">
        <xsl:element name="Root">
            <xsl:variable name="Airlines" select="//Airline"/>
            <xsl:for-each select="$Airlines">
                <xsl:if test="not(preceding::Airline[.=current()/text()])">
                    <xsl:element name="SpecificAirline">
                        <xsl:value-of select="text()"/>
                    </xsl:element>
                </xsl:if>
            </xsl:for-each>
        </xsl:element>
    </xsl:template>
</xsl:stylesheet>

By applying above XSLT i get the below output:

Output:

<Root>
  <SpecificAirline>AB</SpecificAirline>
  <SpecificAirline>CD</SpecificAirline>
  <SpecificAirline>EF</SpecificAirline>
  <SpecificAirline>SD</SpecificAirline>
  <SpecificAirline>XY</SpecificAirline>
  <SpecificAirline>ZZ</SpecificAirline>
</Root>

As per my requirement i need to get only first five airlines

Expected Output:

<Root>
  <SpecificAirline>AB</SpecificAirline>
  <SpecificAirline>CD</SpecificAirline>
  <SpecificAirline>EF</SpecificAirline>
  <SpecificAirline>SD</SpecificAirline>
  <SpecificAirline>XY</SpecificAirline>
</Root>

Please help. Thanks.

Answer 1

I have used a grouping described here: how to apply group by on xslt elements

And array index limitation 5 >= position() described here: http://www.w3schools.com/xpath/xpath_functions.asp#context

<?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:key name="airlinetext" match="Airline" use="text()" />

    <xsl:template match="Response">
        <xsl:element name="Root">
            <xsl:apply-templates select="(//Airline[generate-id(.)=generate-id(key('airlinetext',text())[1])])[5&gt;=position()]"/>
        </xsl:element>
    </xsl:template>

    <xsl:template match="Airline">
                <xsl:element name="SpecificAirline">
                    <xsl:value-of select="text()"/>
                </xsl:element>
    </xsl:template>

</xsl:stylesheet>