A nice extension is to extend this code so that the Host header/Google Analytics tag pairs can be read from a file. This file, residing in $ZEUSHOME/zxtm/conf/extra/ will have the format "<site regex> <account>" separated by any number of tabs and/or spaces. These expressions are applied, from top to bottom, to the response Host header, and the account number from the first match is added to the page. An example analytics.accounts file might be:

support\.zeus\.com  UA-xxxxx-1
www\.zeus\.com      UA-xxxxx-2
\.zeus\.com         UA-xxxxx-3

The code to achieve this is:

#
# Google Analytics Auto-tagger
#
# Automatically add Google's Analytics Javascript to all returned HTML
# pages.
# 

$debug = 0;
$googlepath = "http://www.google-analytics.com/urchin.js";
$filename = "analytics.accounts";

$contentType = http.getResponseHeader( "Content-Type" );
if( ! string.startsWith( $contenttype, "text/html" ) ) break;
if( "" != http.getHeader( "Content-Range" ) ) break;
http.removeResponseHeader( "Content-MD5" );

$header = http.getHeader( "Host" );

#
# Read in filter settings from external file
#

if( resource.exists( $filename ) ) {

  $mtime = data.get( "ga_mtime" );
  if( "" == $mtime || $mtime != resource.getMTime( $filename )
    || "" == data.get( "ga_fileread" ) ) {

    #
    # Need to (re)read file contents
    #
    log.info( "Google Analytics data stale: Re-reading " . $filename );

    $contents = resource.get( $filename );
    $contents = string.regexsub( $contents, "[ \t]+", " ", "g" );
    $contents = string.regexsub( $contents, "^ ", "", "g" );
    $contents = string.regexsub( $contents, " $", "", "g" );
    $contents = string.regexsub( $contents, " ?\n+ ?", "\n", "g" );

    if( "" != $contents ) {
      $mtime = resource.getMTime( $filename );
      data.set( "ga_mtime", $mtime );
      log.info( "Successfully found and loaded " . $filename
        . ", last modified " . $mtime );

      $counter = 0;

      while( string.regexmatch( $contents
        , "^([^ ]+) (UA-[0-9]{5}-[0-9]{1,2})(\n(.*))?$", "i" ) ) {
        $host = $1;
        $account = $2;
        $contents = $4;
        if( ! string.contains( $host, "#" ) ) {
          data.set( "ga_host" . $counter, $host );
          data.set( "ga_acct" . $counter, $account );
          $counter = $counter + 1;
          log.info( "Found account number " . $account . " for site "
            . $host . " (" . $counter . ")" );
        }
      }


      #
      # Done reading file
      #
      log.info( "Read " . $counter
        . " Google Analytics tags, current memory usage is "
        . data.getMemoryUsage() . " bytes" );
      $counter = $counter - 1;
      data.set( "ga_fileread", $counter );

    } else {
      log.warn( $filename
        . " exists but is blank - no data loaded" );
      data.set( "ga_mtime", "" );
      data.set( "ga_fileread", "" );
    }
  }
} else {
  log.warn( "Cannot read $ZEUSHOME/zxtm/conf/extra/"
    . $filename . " to check tags for " . $header );
  data.set( "ga_mtime", "" );
  data.set( "ga_fileread", "" );
}

#
# Detect whether Host header matches
#
$maxcounter = data.get( "ga_fileread" );
$matched = 0;
$counter = 0;
$acct = "";
if( "" != $maxcounter ) {
  $nexthost = data.get( "ga_host" . $counter );
  if( 1 == $debug ) log.info( "$header is " . $header );
  while( 0 == $matched && "" != $nexthost
      && $counter <= $maxcounter ) {
    if( string.regexmatch( $header, $nexthost ) ) {
      $acct = data.get( "ga_acct" . $counter );
      log.info( "Host " . $header . " matches site "
        . $nexthost . " and account " . $acct );
      $matched = 1;
    } else {
      if( 1 == $debug ) log.info( "Unmatched site: " . $nexthost );
    }
    $counter = $counter + 1;
    $nexthost = data.get( "ga_host" . $counter );
  }
}

#
# Set Google Analytics code if Host header matches
#
if( 0 == $matched ) break;
if( "" == $acct ) break;

if( 1 == $debug ) log.info( "Building response for " . $header . http.getPath() );

$body = http.getResponseBody();
if( string.contains( $body, $googlepath ) ) break;

$script = "\n"
        . "<script src=\"" . $googlepath . "\" type=\"text/javascript\">\n"
        . "</script>\n"
        . "<script type=\"text/javascript\">\n"
        . "_uacct = \"" . $acct . "\";\n"
        . "urchinTracker();\n"
        . "</script>\n";

if( string.regexmatch( $body, "^(.*)</body>(.*?)$", "i" ) ) {
  http.setResponseBody( $1 . $script . "</body>" . $2 );
}

Please note that for ZXTM versions 3.1r1 and prior, Content-Encoding and Transfer-Encoding headers should be removed in a Request Rule before this Response Rule is run, in order to correctly tag compressed responses. In ZXTM 4.0 and above, responses are automatically decompressed if necessary!

Google Analytics customer numbers is now 6 digits long so the line containing

, "^([^ ]+) (UA-[0-9]{5}-[0-9]{1,2})(\n(.*))?$", "i" ) ) {

should be replaced with

, "^([^ ]+) (UA-[0-9]{5,6}-[0-9]{1,2})(\n(.*))?$", "i" ) ) {

But really nice and usefull script!

Is there a updated version of this code to support the new google code which is more complex?

Hi Luke, The new Google Analytics code is documented here. So, where the code above says

$script = some javascript

change it to something like:

$script = 
   "<script type=\"text/javascript\">" .
   "var gaJsHost = " .
     "((\"https:\" == document.location.protocol) ? " .
     "\"https://ssl.\" : \"http://www.\");" .
   "document.write(unescape( " .
     "\"%3Cscript src='\"+gaJsHost+\"google-analytics.com/ga.js' " .
     "type='text/javascript'%3E%3C/script%3E\"" .
   "));" .
   "</script>".
   "<script type=\"text/javascript\">".
   "var pageTracker = _gat._getTracker(\"" . $uacct . "\");".
   "pageTracker._trackPageview();".
   "</script>";