使用XSLT将XML转换为CSV

Question

I am looking for an intelligent efficient XSLT which does convert an XML document to CSV data. It should take care of all possible elements in the child nodes. For example, the XML looks like this

<?xml version="1.0" encoding="ISO-8859-1"?>
<sObjects>
   <sObject>
     <Name>Raagu</Name>
     <BillingStreet>Hoskote</BillingStreet>
   </sObject>
   <sObject>
      <Name>Rajath</Name>
      <BillingStreet>BTM</BillingStreet>
      <age>25</age>
   </sObject>
   <sObject>
      <Name>Sarath</Name>
      <BillingStreet>Murgesh</BillingStreet>
      <location>Bangalore</location>
   </sObject>
</sObjects>

And my out put CSV should look like this

Name,BillingStreet,age,location
Raagu,Hoskote,,
Rajath,BTM,25,
Sarath,Murgesh,,Bangalore

All the rows should have fields for all the keys in the CSV even though if the XML does have a value for it.

Following is the XSLT code I came up with by looking at different examples over here.

This is the XSLT I have come up with

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output method="text"/>
    <xsl:variable name="delimiter" select="','"/>

    <xsl:key name="field" match="sObject/*" use="name()"/>

    <xsl:template match="/">

        <xsl:for-each select="/*/*/*[generate-id()=generate-id(key('field', name())[1])]">
            <xsl:value-of select="name()"/>

            <xsl:if test="position() != last()">
                <xsl:value-of select="$delimiter"/>
            </xsl:if>
         </xsl:for-each>

        <xsl:text>&#xa;</xsl:text>

        <xsl:for-each select="/*/sObject">

            <xsl:variable name="property" select="." />
            <xsl:for-each select="$property/*">

                <xsl:variable name="value" select="." />
                <xsl:value-of select="$value"/>
                <xsl:if test="position() != last()">
                    <xsl:value-of select="$delimiter"/>
                </xsl:if>
                <xsl:if test="position() = last()">
                    <xsl:text>&#xa;</xsl:text>
                </xsl:if>

             </xsl:for-each>

        </xsl:for-each>


     </xsl:template>
 </xsl:stylesheet>

and it print this out put

Name,BillingStreet,age,location
Raagu,Hoskote
Rajath,BTM,25
Sarath,Murgesh,Bangalore

But I wanted all the rows should contain values for those many times for all the keys on the first row.

Could you please help me achieve this using XSLT code ?

Answer 1

How about this for a two-step solution

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output method="text"/>
    <xsl:variable name="delimiter" select="','"/>

    <xsl:key name="field" match="/*/*/*" use="local-name()"/>

    <!-- variable containing the first occurrence of each field -->
    <xsl:variable name="allFields"
         select="/*/*/*[generate-id()=generate-id(key('field', local-name())[1])]" />

    <xsl:template match="/">
        <xsl:for-each select="$allFields">
            <xsl:value-of select="local-name()" />
            <xsl:if test="position() &lt; last()">
                <xsl:value-of select="$delimiter" />
            </xsl:if>
        </xsl:for-each>
        <xsl:text>&#10;</xsl:text>
        <xsl:apply-templates select="*/*" />
    </xsl:template>

    <xsl:template match="*">
        <xsl:variable name="this" select="." />
        <xsl:for-each select="$allFields">
            <xsl:value-of select="$this/*[local-name() = local-name(current())]" />
            <xsl:if test="position() &lt; last()">
                <xsl:value-of select="$delimiter" />
            </xsl:if>
        </xsl:for-each>
        <xsl:text>&#10;</xsl:text>
    </xsl:template>
</xsl:stylesheet>

The trick here is that the allFields variable will contain one element with each name, so it's this list of nodes that we iterate over for each row, not simply the elements that actually exist in that row. Since you say that you want to support XML in arbitrary namespaces etc. I've used patterns like /*/*/* rather than hard-coding any particular element names ( /*/*/* simply matches any element that is a grandchild of the document element, regardless of element names), and I'm using local-name() instead of name() to ignore any namespace prefixes (it would treat <sObject> , <sObject xmlns="foo"> and <f:sObject xmlns:f="foo"> exactly the same).