CODEWITHSUNDEEP
xslt
Petras
Petras

Reputation: 591

How to find start(min) and end(max) date in xml file?

I have an XML file. I should find for same field2 start(min) date and End(max) date from field3. Maybe xsl have some function to find it.Because I try do it trying to find min month and min day and max month, max day. XML:

<document>
    <line id="0">
        <field id="2">X111</field>
        <field id="3">2011-03-31</field>
    </line>
    <line id="1">
        <field id="2">X111</field>
        <field id="3">2011-04-04</field>
    </line>
    <line id="2">
        <field id="2">X111</field>
        <field id="3">2011-04-02</field>
    </line>
    <line id="3">
        <field id="2">X222</field>
        <field id="3">2011-04-04</field>
    </line>
    <line id="4">
        <field id="2">X222</field>
        <field id="3">2011-04-01</field>
    </line>
    <line id="4">
        <field id="2">X333</field>
        <field id="3">2011-04-01</field>
    </line>
</document>

Output:

<document>
<Message>
    <ID>X111</ID>
    <dateStart>2011-03-31</dateStart>
    <dateEnd>2011-04-04</dateEnd>
</Message>
<Message>
    <ID>X222</ID>
    <dateStart>2011-04-01</dateStart>
    <dateEnd>2011-04-04</dateEnd>
</Message>
<Message>
    <ID>X333</ID>
    <dateStart>2011-04-01</dateStart>
    <dateEnd>2011-04-01</dateEnd>
</Message>
</document>

Please help to solve it. I'm working with stylesheet version="1.0".

Upvotes: 2

Views: 3779

Answers (3)

Wayne
Wayne

Reputation: 60424

I upvoted @mousio's answer, but I'd prefer to see the first of each line type handled in its own template. So, in the spirit of TMTOWTDI, here's how I would have done it:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output method="xml" indent="yes" omit-xml-declaration="yes" />
    <xsl:key name="byField2" match="line" use="field[@id=2]" />
    <xsl:template match="/">
        <document>
            <xsl:apply-templates select="document/line" />
        </document>
    </xsl:template>
    <xsl:template match="line[count(.|key('byField2', field[@id=2])[1])=1]">
        <Message>
            <ID><xsl:value-of select="field[@id=2]" /></ID>
            <xsl:apply-templates select="key('byField2', field[@id=2])" mode="m">
                <xsl:sort select="field[@id=3]" />
            </xsl:apply-templates>
        </Message>
    </xsl:template>
    <xsl:template match="line" mode="m">
        <xsl:if test="position()=1">
            <dateStart><xsl:value-of select="field[@id=3]" /></dateStart>
        </xsl:if>
        <xsl:if test="position()=last()">
            <dateEnd><xsl:value-of select="field[@id=3]" /></dateEnd>
        </xsl:if>
    </xsl:template>
    <xsl:template match="line" />
</xsl:stylesheet>

I think this is easier to read (and probably more efficient on large documents, since it doesn't abuse //).

Upvotes: 2

Dimitre Novatchev
Dimitre Novatchev

Reputation: 243599

This transformation shows how to find the wanted minimum and maximum:

<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="/*">
     <xsl:apply-templates select="line">
       <xsl:sort select="field[@id=3]"/>
     </xsl:apply-templates>
 </xsl:template>

 <xsl:template match="line">
  <xsl:if test="position()=1">
   Earliest:
   <xsl:copy-of select="."/>
  </xsl:if>
  <xsl:if test="position()=last()">
   Latest:
   <xsl:copy-of select="."/>
  </xsl:if>
 </xsl:template>
</xsl:stylesheet>

when applied on the provided XML document:

<document>
    <line id="0">
        <field id="2">X111</field>
        <field id="3">2011-03-31</field>
    </line>
    <line id="1">
        <field id="2">X111</field>
        <field id="3">2011-04-04</field>
    </line>
    <line id="2">
        <field id="2">X111</field>
        <field id="3">2011-04-02</field>
    </line>
    <line id="3">
        <field id="2">X222</field>
        <field id="3">2011-04-04</field>
    </line>
    <line id="4">
        <field id="2">X222</field>
        <field id="3">2011-04-01</field>
    </line>
    <line id="4">
        <field id="2">X333</field>
        <field id="3">2011-04-01</field>
    </line>
</document>

produces:

   Earliest:
   <line id="0">
   <field id="2">X111</field>
   <field id="3">2011-03-31</field>
</line>
   Latest:
   <line id="3">
   <field id="2">X222</field>
   <field id="3">2011-04-04</field>
</line>

Explanation:

Choosing the first and last element from the sorted node-list. The dates are in a "good" format, so they are sorted just as strings.

Upvotes: 0

mousio
mousio

Reputation: 10337

This can probably be optimized but it returns the requested results:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output method="xml" indent="yes" omit-xml-declaration="yes"/>
    <xsl:key name="test" match="line" use="field[@id=2]"/>
    <xsl:template match="/">
        <document>
            <xsl:for-each select="//line[generate-id()=generate-id(key('test',field[@id=2]))]">
                <xsl:sort select="field[@id=2]"/>
                <Message>
                    <ID>
                        <xsl:value-of select="field[@id=2]"/>
                    </ID>
                    <xsl:apply-templates select="key('test',field[@id=2])">
                        <xsl:sort select="field[@id=3]"/>
                    </xsl:apply-templates>
                </Message>
            </xsl:for-each>
        </document>
    </xsl:template>
    <xsl:template match="line">
        <xsl:if test="position()=1">
            <dateStart>
                <xsl:value-of select="field[@id=3]"/>
            </dateStart>
        </xsl:if>
        <xsl:if test="position()=last()">
            <dateEnd>
                <xsl:value-of select="field[@id=3]"/>
            </dateEnd>
        </xsl:if>
    </xsl:template>
</xsl:stylesheet>

Upvotes: 3

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