Question

Is it possible to merge every sequence of nodes of the same specified type? (‘aaa’ in this case) (not just first occurrence of sequence)

Here is my XML input:

<block>
    <aaa>text1</aaa>
    <aaa>text2</aaa>
    <aaa><xxx>text3</xxx></aaa>
    <bbb>text4</bbb>
    <aaa>text5</aaa>
    <bbb><yyy>text6</yyy></bbb>
    <bbb>text7</bbb>
    <aaa>text8</aaa>
    <aaa><zzz>text9</zzz></aaa>
    <aaa>texta</aaa>
</block>

And I want following output:

<block>
    <aaa>text1text2<xxx>text3</xxx></aaa>
    <bbb>text4</bbb>
    <aaa>text5</aaa>
    <bbb><yyy>text6</yyy></bbb>
    <bbb>text7</bbb>
    <aaa>text8<zzz>text9</zzz>texta</aaa>
</block>

Any help appreciated

Answer 1

Here is another way to do this.

First, match on all the child nodes of the block element

<xsl:template match="block/child::*">

Next, check if the element’s most direct sibling has a different name, indicating this is the first of one or more adjacent elements:

<xsl:if test="local-name(preceding-sibling::*[position()=1]) != $name">

If so, you can copy that node. Then, you need to copy of following siblings with the same name. I did this by recursively calling a template on each immediately following sibling with the same name

<xsl:apply-templates select="following-sibling::*[1][local-name()=$name]" mode="next"/>

Putting this all together gives

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
   <xsl:output method="xml" indent="yes"/>

   <!-- Match children of the block element -->
   <xsl:template match="block/child::*">
      <xsl:variable name="name" select="local-name()"/>

      <!-- Is this the first element in a sequence? -->
      <xsl:if test="local-name(preceding-sibling::*[position()=1]) != $name">
         <xsl:copy>
            <xsl:apply-templates />

            <!-- Match the next sibling if it has the same name -->
            <xsl:apply-templates select="following-sibling::*[1][local-name()=$name]" mode="next"/>
         </xsl:copy>
      </xsl:if>
   </xsl:template>

   <!-- Recursive template used to match the next sibling if it has the same name -->
   <xsl:template match="block/child::*" mode="next">
      <xsl:variable name="name" select="local-name()"/>
         <xsl:apply-templates />
      <xsl:apply-templates select="following-sibling::*[1][local-name()=$name]" mode="next"/>
   </xsl:template>

   <!-- Template used to copy a generic node -->
   <xsl:template match="@* | node()">
         <xsl:copy>
            <xsl:apply-templates select="@* | node()"/>
         </xsl:copy>
   </xsl:template>
</xsl:stylesheet>