Question

I have xml document like below,

<chapter xmlns:xi="http://www.w3.org/2001/XInclude" xml:id="chapter1">
<title>First chapter</title>
<section xml:id="section1">
                <imageobject>
                    <image fileref="images/image1.jpg"/>
                </imageobject>
                <imageobject>
                    <image fileref="images/image2.jpg"/>
                </imageobject>
</section>
    <section xml:id="section2" xml:base="../other/section1.xml">  
                    <imageobject>
                        <image fileref="images/image1.jpg"/>
                    </imageobject>
                    <imageobject>
                        <image fileref="images/image2.jpg"/>
                    </imageobject>

<section xml:id="section3" xml:base="../some-other/more/section3.xml">
                    <imageobject>
                        <image fileref="images/image1.jpg"/>
                    </imageobject>
    </section>
    </section>
    <section xml:id="section4" xml:base="../some-other/section4.xml">
                    <imageobject>
                        <image fileref="images/image2.jpg"/>
                    </imageobject>
    </section>
 </chapter>

Be cause of same image name is repeated in different sections, I am renaming all image names other than first section using a java class. Then I can generate a list of renamed image names.

Now I want to reflect those changes in the above xml file also. As example when I rename “image1.jpg” to “aaa.jpg” in section2, I need to reflect that change in the my initial xml by generating a new xml with new renamed image names.

For that purpose, I am using Ant script which uses XSLT 1.0 and take my first xml and renamed image list as inputs and generate a new xml document with new fileref values. How I can make that XSLT and use it in my Ant script.

Here is my new renamed images list.

<Imagedata>
  <section>
    <sectionID>section2</sectionID>
    <relativepath>images/aaa.jpg</relativepath>
    <relativepath>images/bbb.jpg</relativepath>
  </section>
  <section>
    <sectionID>section3</sectionID>
    <relativepath>images/ccc.jpg</relativepath>
  </section>
   <section>
    <sectionID>section4</sectionID>
    <relativepath>images/ddd.jpg</relativepath>
  </section>
</Imagedata>

And my new final xml will be some thing like,

<chapter xmlns:xi="http://www.w3.org/2001/XInclude" xml:id="chapter1">
    <title>First chapter</title>
    <section xml:id="section1">
                    <imageobject>
                        <image fileref="images/image1.jpg"/>
                    </imageobject>
                    <imageobject>
                        <image fileref="images/image2.jpg"/>
                    </imageobject>
    </section>
        <section xml:id="section2" xml:base="../other/section1.xml">  
                        <imageobject>
                            <image fileref="images/aaa.jpg"/>
                        </imageobject>
                        <imageobject>
                            <image fileref="images/bbb.jpg"/>
                        </imageobject>

    <section xml:id="section3" xml:base="../some-other/more/section3.xml">
                        <imageobject>
                            <image fileref="images/ccc.jpg"/>
                        </imageobject>
        </section>
        </section>
        <section xml:id="section4" xml:base="../some-other/section4.xml">
                        <imageobject>
                            <image fileref="images/ddd.jpg"/>
                        </imageobject>
        </section>
     </chapter>

Thank you..!!

Answer 1

Just for a quick demonstration, I have put the Imagedata document into a variable inside the stylesheet show below. In real use, you will pass in a parameter which is the URI of the Image data document, like so …

<xsl:param name="ImageDataURI" />
<xsl:variable name="ImageData" select="document($ImageDataURI)" />

That aside, this XSLT 1.0 style-sheet…

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:msxsl="urn:schemas-microsoft-com:xslt">
<xsl:output method="xml" indent="yes"/>

<xsl:variable name="ImageData">
<Imagedata>
  <section>
    <sectionID>section2</sectionID>
    <relativepath>images/aaa.jpg</relativepath>
    <relativepath>images/bbb.jpg</relativepath>
  </section>
  <section>
    <sectionID>section3</sectionID>
    <relativepath>images/ccc.jpg</relativepath>
  </section>
   <section>
    <sectionID>section4</sectionID>
    <relativepath>images/ddd.jpg</relativepath>
  </section>
</Imagedata>
</xsl:variable>

<xsl:template match="@*|node()">
  <xsl:copy>
   <xsl:apply-templates select="@*|node()"/>
  </xsl:copy>
</xsl:template>

<xsl:template match="image/@fileref">
  <xsl:attribute name="fileref">
    <xsl:value-of select="
    (msxsl:node-set($ImageData)/Imagedata/section/
    sectionID[.=current()/../../../self::section/@xml:id]/
    following-sibling::relativepath[
     count( current()/../../preceding-sibling::imageobject) + 1
      ] | .)[1]"/>
  </xsl:attribute>  
</xsl:template>

</xsl:stylesheet>

…will transform your supplied input document to the expected output document.

Explanation

Consider the value-of expression in the last template. Starting from our matched fileref attribute, we navigate up until we get to section and get its id. This is given by the expression …

current()/../../../self::section/@xml:id

Then we take our look-up data and find the sectionID s. This is given by expression…

msxsl:node-set($ImageData)/Imagedata/section/sectionID

We need to cross-link these sections by section name. We achieve this by applying a predicate to the sectionID that its value must be the section value of the focus item. The predicate is here…

[.=current()/../../../self::section/@xml:id]

Now we have found the right lookup-section, we need to index into it by our current position of the focus item within the document-section. We calculate our position by counting the preceding siblings and adding one, like thus …

count( current()/../../preceding-sibling::imageobject) + 1

And thus the look-up replacement node, if it exists, is given by…

msxsl:node-set($ImageData)/Imagedata/section/
sectionID[.=current()/../../../self::section/@xml:id]/
following-sibling::relativepath[
 count( current()/../../preceding-sibling::imageobject) + 1

That’s all well and good when a replacement is in order, but there are cases where there is no co-responding lookup. In this case our attribute needs to retain its original value. We achieve this by an expression of the form …

( $something | .)[1]

If $something doesn’t exist (meaning it;s value is the empty sequence), then the above expression simply returns the focus item. If it does exist, then either the first item of $something will be returned or the focus item. Normally the union operator concatenates two sequences, de-dups and sorts in document order. But the two operands come from different documents, so there is no sorting nor de-duping going on. Thus the expression returns the replacement node when it exists, or if not then the focus item.