Question

Here’s my problem.I have 2 xmlfiles with identical structure, with the second xml containing only few node compared to first.

File1

  <root>     <alpha>111</alpha>     <beta>22</beta>     <gamma></gamma>     <delta></delta>   </root> 

File2

 <root>     <beta>XX</beta>     <delta>XX</delta>  </root> 

This’s what the result should look like

 <root>     <alpha>111</alpha>     <beta>22</beta>     <gamma></gamma>     <delta>XX</delta>  </root> 

Basically if the node contents of any node in File1 is blank then it should read the values from File2(if it exists, that is).

I did try my luck with Microsoft XmlDiff API but it didn’t work out for me(the patch process didn’t apply changes to the source doc). Also I’m a bit worried about the DOM approach that it uses, because of the size of the xml that I’ll be dealing with. Can you please suggest a good way of doing this. I’m using C# 2

Answer 1

Here is a little bit simpler and more efficient solution that that proposed by Alastair (see my comment to his solution).

This transformation:

 <xsl:stylesheet version='1.0'   xmlns:xsl='http://www.w3.org/1999/XSL/Transform' >   <xsl:output omit-xml-declaration='yes' indent='yes'/>      <xsl:variable name='vFile2'          select='document('File2.xml')'/>      <xsl:template match='*'>       <xsl:copy>         <xsl:copy-of select='@*'/>             <xsl:apply-templates/>         </xsl:copy>     </xsl:template>      <xsl:template match='*[not(text())]'>       <xsl:copy>         <xsl:copy-of           select='$vFile2/*/*[name() = name(current())]/text()'/>         </xsl:copy>     </xsl:template> </xsl:stylesheet> 

when applied on this XML document:

 <root>     <alpha>111</alpha>     <beta>22</beta>     <gamma></gamma>     <delta></delta> </root> 

produces the wanted result:

 <root>     <alpha>111</alpha>     <beta>22</beta>     <gamma></gamma>     <delta>XX</delta> </root>