Retrieve Selected Records With Xpath
===

I wonder whether someone may be able to help me please.

I'm using the script below to create a 'gallery' page. 

    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
    <html xmlns="http://www.w3.org/1999/xhtml"> 
    <?php 
       
      //This variable specifies relative path to the folder, where the gallery with uploaded files is located. 
      //Do not forget about the slash in the end of the folder name. 
      $galleryPath = 'UploadedFiles/'; 
        
      $thumbnailsPath = $galleryPath . 'Thumbnails/'; 
        
      $absGalleryPath = realpath($galleryPath) . DIRECTORY_SEPARATOR; 
        
      $descriptions = new DOMDocument('1.0'); 
      $descriptions->load($absGalleryPath . 'files.xml'); 
      
      
    ?>
    <head> 
      <title>Gallery</title> 
      <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> 
      <link href="Libraries/fancybox/jquery.fancybox-1.3.1.css" rel="stylesheet" type="text/css" /> 
      <link href="Styles/style.css" rel="stylesheet" type="text/css" /> 
      <!--[if IE]>   
      <link href="Styles/ie.css" rel="stylesheet" type="text/css" /> 
      <![endif]-->
      <script src="Libraries/jquery/jquery-1.4.3.min.js" type="text/javascript"></script> 
      <script src="Libraries/fancybox/jquery.fancybox-1.3.1.pack.js" type="text/javascript"></script> 
      <script type="text/javascript"> 
      
      $(function() { $('a.fancybox').fancybox(); }); 
        
      </script> 
      <style type="text/css">
    <!--
    .style1 {
    	font-size: 14px;
    	margin-right: 110px;
    }
    .style4 {font-size: 12px}
    -->
      </style>
    </head>
    <body style="font-family: Calibri; color:  #505050; font-size: 9px; border-bottom-width: thin; margin-top: 5px; margin-left: -475px; margin-right: 1px; margin-bottom: -10px;">
    <div align="right" class="style1"> <a href = "imagefolders.php" /> View Uploaded Images In Folder Structure <a/> &larr; View All Uploaded Images </div>
      <form id="gallery" class="page"> 
      <div id="container"> 
        <div id="center"> 
          <div class="aB"> 
            <div class="aB-B"> 
              <?php if ('Uploaded files' != $current['title']) :?>
              <?php endif;?>
              <div class="demo"> 
                <div class="inner"> 
                  <div class="container"> 
                    <div class="gallery"> 
                      <ul class="gallery-image-list"> 
                      <?php for ($i = 0; $i < $descriptions->documentElement->childNodes->length; $i++) : 
                              $xmlFile = $descriptions->documentElement->childNodes->item($i); 
                              $name = htmlentities($xmlFile->getAttribute('originalname'), ENT_COMPAT, 'UTF-8'); 
    						  $description = htmlentities($xmlFile->getAttribute('description'), ENT_COMPAT, 'UTF-8'); 
    						  $folder = htmlentities($xmlFile->getAttribute('folder'), ENT_COMPAT, 'UTF-8'); 
                              $source = $galleryPath . rawurlencode($xmlFile->getAttribute('source')); 
                              $thumbnail = $thumbnailsPath . rawurlencode($xmlFile->getAttribute('thumbnail')); 
                      ?>
                        <li class="item"> 
                          <a class="fancybox" target="_blank" rel="original" href="<?php echo $source; ?>"><img class="preview" 
                            alt="<?php echo $name; ?>"  src="<?php echo $thumbnail; ?>" /></a>						</li>
    						<li class="item"></li>
    						<p><span class="style4"><b>Image Description:</b> <?php echo htmlentities($xmlFile->getAttribute('description'));?> <br />
    				            <b>Image contained in folder:</b> <?php echo htmlentities($xmlFile->getAttribute('folder'));?> </span><br />  
    						  <?php endfor; ?>
    				          </li>
    	                </p>
    				  </ul>
                    </div> 
                  </div> 
                </div> 
              </div> 
            </div> 
          </div> 
        </div> 
        </div> 
            <div class="aB-a">        </div> 
          </div> 
        </div> 
      </div> 
      </form> 
    </body> 
    </html>

The data for this page comes from the xml file 'files.xml' an extract of which is shown below:

    <?xml version="1.0" encoding="utf-8" ?> 
    - <files>
      <file name="Test 1/article-0-07D01B74000005DC-138_468x617.jpg" source="article-0-07D01B74000005DC-138_468x617.jpg" size="143110" originalname="article-0-07D01B74000005DC-138_468x617.jpg" thumbnail="article-0-07D01B74000005DC-138_468x617.jpg" description="No description provided" userid="1" locationid="1" folder="Test_1" /> 
      </files>

What I would like to do now is filter the images shown from the xml file, to be more specific those that match the current 'userid' and 'locationid' both of which will be values in two text fields on the gallery page.

From some invaluable help and guidance I've gleened from this site at http://stackoverflow.com/questions/9749774/xml-select-where-statement, and from articles I've read since, I believe that I need to use xpath.

The problem I have is that all the tutorials I've read start from scratch i.e. the loading of the XML etc. and I'm not sure how I can use my current page script whilst incorporating a XPath query.

I just wondered whether someone may be able to take a look at what I have already and offer some guidance how I can incorporate the XPath query into my page.

Many thanks

