Hello, I am trying to get to work a tagging system for the images in the media section. I added a multiple dropdown list as part of the Image datatype, and I have previously filled the multiple dropdown list with prevalues.

I have been trying to loop all the images in a particular sub-folder in the media section and to check if the selected prevalues are matching the ones set in the doc type.

Here is the code I have borrowed from here and some good ideas from here and here

So far I just want to loop through all the images in the selected subfolder and list the matching prevalues. But I get a error on this one:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE xsl:stylesheet [
    <!ENTITY nbsp "&#x00A0;">
]>
<xsl:stylesheet
    version="1.0"
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:msxml="urn:schemas-microsoft-com:xslt"
    xmlns:umbraco.library="urn:umbraco.library"
    exclude-result-prefixes="msxml umbraco.library">
    <xsl:output method="xml" omit-xml-declaration="yes"/>
    <xsl:param name="currentPage"/>
    <!-- MAIN TEMPLATE -->
    <xsl:template match="/">
    <!-- Variable with the selected media folder ID -->
        <xsl:variable name="mediaFolderID" select="$currentPage/data[@alias='SelectedFolder']"/>
        <!-- Call template generates the HTML for the images-->
        <xsl:call-template name="LoopThroughImagesInFolder">
            <xsl:with-param name="mediaFolderID">
                    <xsl:value-of select="$mediaFolderID"/>
            </xsl:with-param>
        </xsl:call-template>
    </xsl:template>
    <!-- LOOP THROUGH IMAGES IN FOLDER TEMPLATE -->
    <xsl:template name="LoopThroughImagesInFolder">
        <!-- Parameter with a media folder ID -->
        <xsl:param name="mediaFolderID"/>
        <!-- Check that you really have an ID -->
        <!-- Without this test the script can fail -->
        <xsl:if test="$mediaFolderID &gt; 0">
            
            <!-- Get the media node using the ID -->
            <xsl:variable name="images" select="umbraco.library:GetMedia($mediaFolderID, 1)" />
            <!-- Check if the folder contains any child nodes -->
            <xsl:if test="count($images/node) &gt; 0">;       <!-- Start iterating the child nodes -->
                <xsl:for-each select="$images/node">
                    <xsl:choose>
                        <!-- Is it an image?
                        Please note that this only works if your images have the 
                        @nodeTypeAlias "Image". If you have called it something else, 
                        you need to replace the name. 
                        -->
                        <xsl:when test="string(./@nodeTypeAlias) = 'Image'">
                            <!-- Print the image code -->
    <ul>
     <xsl:for-each select="umbraco.library:GetPreValues($currentPage)//preValues">
     <li>
             <a href="#">
       <xsl:value-of select="." />
      </a>                
     </li>
     </xsl:for-each>
    </ul>
                        </xsl:when>
                    </xsl:choose>
                </xsl:for-each>
            </xsl:if>
        </xsl:if>
 </xsl:template>
</xsl:stylesheet>