*** ../TWiki20040901/lib/TWiki.pm	2004-08-30 08:46:11.000000000 +0200
--- lib/TWiki.pm	2005-08-19 19:30:07.000000000 +0200
***************
*** 77,83 ****
          $doLogTopicChanges $doLogTopicSearch $doLogRegistration
          $superAdminGroup $doSuperAdminGroup $OS
          $disableAllPlugins $attachAsciiPath $displayTimeValues
!         $dispScriptUrlPath $dispViewPath
      );
  
  # Internationalisation (I18N) config from TWiki.cfg:
--- 77,83 ----
          $doLogTopicChanges $doLogTopicSearch $doLogRegistration
          $superAdminGroup $doSuperAdminGroup $OS
          $disableAllPlugins $attachAsciiPath $displayTimeValues
!         $dispScriptUrlPath $dispViewPath $expirationLastDateOffset
      );
  
  # Internationalisation (I18N) config from TWiki.cfg:
***************
*** 781,800 ****
  
  sub writeHeader
  {
!     my( $query ) = @_;
  
      # FIXME: Pass real content-length to make persistent connections work
      # in HTTP/1.1 (performance improvement for browsers and servers). 
      # Requires significant but easy changes in various places.
  
      # Just write a basic content-type header for text/html
!     writeHeaderFull( $query, 'basic', 'text/html', 0);
  }
  
  
  =pod
  
! ---++ writeHeaderFull( $query, $pageType, $contentType, $contentLength )
  
  Builds and outputs HTTP headers.  $pageType should (currently) be either
  "edit" or "basic".  $query is the object from the CGI module, not the actual
--- 781,800 ----
  
  sub writeHeader
  {
!     my( $query, $lastModifiedDate) = @_;
  
      # FIXME: Pass real content-length to make persistent connections work
      # in HTTP/1.1 (performance improvement for browsers and servers). 
      # Requires significant but easy changes in various places.
  
      # Just write a basic content-type header for text/html
!     writeHeaderFull( $query, 'basic', 'text/html', 0, $lastModifiedDate);
  }
  
  
  =pod
  
! ---++ writeHeaderFull( $query, $pageType, $contentType, $contentLength, $expireDate)
  
  Builds and outputs HTTP headers.  $pageType should (currently) be either
  "edit" or "basic".  $query is the object from the CGI module, not the actual
***************
*** 817,823 ****
  
  sub writeHeaderFull
  {
!     my( $query, $pageType, $contentType, $contentLength ) = @_;
  
      # Handle Edit pages - future versions will extend to caching
      # of other types of page, with expiry time driven by page type.
--- 817,823 ----
  
  sub writeHeaderFull
  {
!     my( $query, $pageType, $contentType, $contentLength, $lastModifiedDate) = @_;
  
      # Handle Edit pages - future versions will extend to caching
      # of other types of page, with expiry time driven by page type.
***************
*** 850,858 ****
  			    -cache_control => "max-age=$expireSeconds",
  			 );
      } elsif ($pageType eq 'basic') {
  	$coreHeaders = $query->header(
! 	    		    -content_type => $contentType,
  			 );
      } else {
  	writeWarning( "===== invalid page type in TWiki.pm, writeHeaderFull(): $pageType" );
      }
--- 850,877 ----
  			    -cache_control => "max-age=$expireSeconds",
  			 );
      } elsif ($pageType eq 'basic') {
+       if ($lastModifiedDate) {
+         my $lastModifiedDateString =  &formatTime($lastModifiedDate, '\$http');
+ 	if ($expirationLastDateOffset) {
+ 	  my $expirationDateString = &formatTime($lastModifiedDate + 
+ 						 $expirationLastDateOffset,
+ 						 '\$http');
+ 	  $coreHeaders = $query->header(
+  			    -content_type => $contentType,
+ 			    -last_modified => $lastModifiedDateString,
+ 			    -expires => $expirationDateString,
+ 			 );
+ 	} else {
+ 	  $coreHeaders = $query->header(
+  			    -content_type => $contentType,
+ 			    -last_modified => $lastModifiedDateString,
+ 			 );
+ 	}
+       } else {
  	$coreHeaders = $query->header(
!  			    -content_type => $contentType,
  			 );
+       }
      } else {
  	writeWarning( "===== invalid page type in TWiki.pm, writeHeaderFull(): $pageType" );
      }
***************
*** 2096,2101 ****
--- 2115,2127 ----
  
      } # else is a file with relative path, e.g. $dataDir/../../path/to/non-twiki/file.ext
  
+     # sets correct last-modified-date
+     my ($revdate) = &TWiki::Store::getRevisionInfoFromMeta( $theWeb, $theTopic, $meta);
+     if ($revdate && (!$TWiki::UI::View::lastModifiedDate ||
+ 		     ($TWiki::UI::View::lastModifiedDate < $revdate))) {
+       $TWiki::UI::View::lastModifiedDate = $revdate;
+     }
+ 
      $text = applyPatternToIncludedText( $text, $pattern ) if( $pattern );
  
      # handle all preferences and internal tags (for speed: call by reference)
*** ../TWiki20040901/lib/TWiki/UI/View.pm	2004-08-25 08:36:15.000000000 +0200
--- lib/TWiki/UI/View.pm	2005-08-19 19:30:07.000000000 +0200
***************
*** 44,49 ****
--- 44,51 ----
  
  =cut
  
+ $TWiki::UI::View::lastModifiedDate = '';
+ 
  sub view {
    my ( $webName, $topic, $userName, $query ) = @_;
  
***************
*** 62,67 ****
--- 64,70 ----
    my $extra = "";
    my $wikiUserName = &TWiki::userToWikiName( $userName );
    my $revdate = "";
+   my $revdatenum = "";
    my $revuser = "";
  
    $skin = &TWiki::Prefs::getPreferencesValue( "SKIN" ) unless ( $skin );
***************
*** 102,109 ****
      } else {
        ( $meta, $text ) = &TWiki::Store::readTopic( $webName, $topic );
      }
!     ( $revdate, $revuser, $maxrev ) = &TWiki::Store::getRevisionInfoFromMeta( $webName, $topic, $meta);
!     $revdate = TWiki::formatTime( $revdate );
  
      if( $rev ) {
        $rev =~ s/r?1\.//go;  # cut 'r' and major
--- 105,112 ----
      } else {
        ( $meta, $text ) = &TWiki::Store::readTopic( $webName, $topic );
      }
!     ( $revdatenum, $revuser, $maxrev ) = &TWiki::Store::getRevisionInfoFromMeta( $webName, $topic, $meta);
!     $revdate = TWiki::formatTime( $revdatenum );
  
      if( $rev ) {
        $rev =~ s/r?1\.//go;  # cut 'r' and major
***************
*** 119,126 ****
        } else {
          ( $meta, $text ) = &TWiki::Store::readTopicVersion( $webName, $topic, "1.$rev" );
        }
!       ( $revdate, $revuser ) = &TWiki::Store::getRevisionInfo( $webName, $topic, "1.$rev");
!       $revdate = TWiki::formatTime( $revdate );
        $extra .= "r1.$rev";
      }
    } else {
--- 122,129 ----
        } else {
          ( $meta, $text ) = &TWiki::Store::readTopicVersion( $webName, $topic, "1.$rev" );
        }
!       ( $revdatenum, $revuser ) = &TWiki::Store::getRevisionInfo( $webName, $topic, "1.$rev");
!       $revdate = TWiki::formatTime( $revdatenum );
        $extra .= "r1.$rev";
      }
    } else {
***************
*** 132,137 ****
--- 135,141 ----
      }
      $extra .= " (not exist)";
    }
+   $TWiki::UI::View::lastModifiedDate = $revdatenum;
  
    if( $viewRaw ) {
      $extra .= " raw=$viewRaw";
***************
*** 293,300 ****
  
    # Write header based on "contenttype" parameter, used to produce
    # MIME types like text/plain or text/xml, e.g. for RSS feeds.
    if( $contentType ) {
!     TWiki::writeHeaderFull( $query, 'basic', $contentType, 0);
      if( $skin =~ /^rss/ ) {
        $tmpl =~ s/<img [^>]*>//g;  # remove image tags
        $tmpl =~ s/<a [^>]*>//g;    # remove anchor tags
--- 297,307 ----
  
    # Write header based on "contenttype" parameter, used to produce
    # MIME types like text/plain or text/xml, e.g. for RSS feeds.
+   if (!$TWiki::UI::View::lastModifiedDate) {
+     $TWiki::UI::View::lastModifiedDate = time();
+   }
    if( $contentType ) {
!     TWiki::writeHeaderFull( $query, 'basic', $contentType, 0, $TWiki::UI::View::lastModifiedDate);
      if( $skin =~ /^rss/ ) {
        $tmpl =~ s/<img [^>]*>//g;  # remove image tags
        $tmpl =~ s/<a [^>]*>//g;    # remove anchor tags
***************
*** 306,312 ****
      $tmpl =~ s/<a [^>]*>//g;    # remove anchor tags
      $tmpl =~ s/<\/a>//g;        # remove anchor tags
    } else {
!     TWiki::writeHeader( $query );
    }
  
    # print page content
--- 313,319 ----
      $tmpl =~ s/<a [^>]*>//g;    # remove anchor tags
      $tmpl =~ s/<\/a>//g;        # remove anchor tags
    } else {
!     TWiki::writeHeader( $query, $TWiki::UI::View::lastModifiedDate);
    }
  
    # print page content
*** ../TWiki20040901/lib/TWiki/Search.pm	2004-07-30 20:29:16.000000000 +0200
--- lib/TWiki/Search.pm	2005-08-19 19:30:07.000000000 +0200
***************
*** 385,390 ****
--- 385,393 ----
  
      my @webList = ();
  
+     # set last-modified date in http headers to now
+     $TWiki::UI::View::lastModifiedDate = '';
+ 
      # A value of 'all' or 'on' by itself gets all webs,
      # otherwise ignored (unless there is a web called "All".)
      my $searchAllFlag = ( $theWebName =~ /(^|[\,\s])(all|on)([\,\s]|$)/i );
*** ../TWiki20040901/lib/TWiki.cfg	2004-08-31 18:35:19.000000000 +0200
--- lib/TWiki.cfg	2005-08-19 19:29:57.000000000 +0200
***************
*** 443,448 ****
--- 443,451 ----
  #                   Enable super-powers to $superAdminGroup members
  #                   see Codev.UnchangeableTopicBug
  $doSuperAdminGroup  = "1";
+ #
+ #		    HTTP Header expire date as offset in seconds from last save
+ $expirationLastDateOffset = 60;
  
  # Return true
  1;