From 209ed51d275be5cc7d97f1e60f7aff2735a03845 Mon Sep 17 00:00:00 2001
From: Antoine Musso <hashar@users.mediawiki.org>
Date: Mon, 11 Dec 2006 19:29:41 +0000
Subject: [PATCH] Implements bug #4673 : Special:Allpages should display
 "previous" link Notes: added a 'prevpage' message, you might want to review
 database queries

---
 RELEASE-NOTES                     |  2 +-
 includes/SpecialAllpages.php      | 56 +++++++++++++++++++++++++++----
 languages/messages/MessagesEn.php |  1 +
 3 files changed, 51 insertions(+), 8 deletions(-)

diff --git a/RELEASE-NOTES b/RELEASE-NOTES
index 8a03d01de2..a8de8927b9 100644
--- a/RELEASE-NOTES
+++ b/RELEASE-NOTES
@@ -268,7 +268,7 @@ it from source control: http://www.mediawiki.org/wiki/Download_from_SVN
   Duplicated code merged into wfResetOutputBuffers() and wfClearOutputBuffers()
 * Special:AllPages : 'next page' link now point to the first title of the next
   chunk instead of pointing to the last title of current chunk.
-
+* (bug 4673) Special:AllPages : add a 'previous' link (new message 'prevpage')
 
 == Languages updated ==
 
diff --git a/includes/SpecialAllpages.php b/includes/SpecialAllpages.php
index 51ef5c9742..c68026af57 100644
--- a/includes/SpecialAllpages.php
+++ b/includes/SpecialAllpages.php
@@ -231,8 +231,6 @@ function showChunk( $namespace = NS_MAIN, $from, $including = false ) {
 			)
 		);
 
-		### FIXME: side link to previous
-
 		$n = 0;
 		$out = '<table style="background: inherit;" border="0" width="100%">';
 
@@ -263,15 +261,52 @@ function showChunk( $namespace = NS_MAIN, $from, $including = false ) {
 	if ( $including ) {
 		$out2 = '';
 	} else {
+
+		# Get the last title from previous chunk
+		$res_prev = $dbr->select(
+			'page',
+			'page_title',
+			array( 'page_namespace' => $namespace, 'page_title < '.$dbr->addQuotes($from) ),
+			$fname,
+			array( 'ORDER BY' => 'page_title DESC', 'LIMIT' => $this->maxPerPage, 'OFFSET' => ($this->maxPerPage - 1 ) )
+		);
+
+		# Get first title of previous complete chunk
+		if( $dbr->numrows( $res_prev ) >= $this->maxPerPage ) {
+			$pt = $dbr->fetchObject( $res_prev );
+			$prevTitle = Title::makeTitle( $namespace, $pt->page_title );
+		} else {
+			# The previous chunk is not complete, need to link to the very first title
+			# available in the database
+			$reallyFirstPage_title = $dbr->selectField( 'page', 'page_title', array( 'page_namespace' => $namespace ), $fname, array( 'LIMIT' => 1) );
+
+			# Show the previous link if it s not the current requested chunk
+			if( $from != $reallyFirstPage_title ) {
+				$prevTitle =  Title::makeTitle( $namespace, $reallyFirstPage_title );
+			} else {
+				$prevTitle = null;
+			}
+		}
+
 		$nsForm = $this->namespaceForm ( $namespace, $from );
 		$out2 = '<table style="background: inherit;" width="100%" cellpadding="0" cellspacing="0" border="0">';
 		$out2 .= '<tr valign="top"><td align="left">' . $nsForm;
 		$out2 .= '</td><td align="right" style="font-size: smaller; margin-bottom: 1em;">' .
 				$sk->makeKnownLink( $wgContLang->specialPage( "Allpages" ),
 					wfMsgHtml ( 'allpages' ) );
-		if ( isset($dbr) && $dbr && ($n == $this->maxPerPage) && ($s = $dbr->fetchObject( $res )) ) {
-			$t = Title::MakeTitle( $s->page_namespace, $s->page_title );
-			$self = SpecialPage::getTitleFor( 'Allpages' );
+
+		$self = SpecialPage::getTitleFor( 'Allpages' );
+
+		# Do we put a previous link ?
+		if( isset( $prevTitle ) &&  $pt = $prevTitle->getText() ) {
+			$q = 'from=' . $prevTitle->getPartialUrl() . ( $namespace ? '&namespace=' . $namespace : '' );
+			$prevLink = $sk->makeKnownLinkObj( $self, wfMsgHTML( 'prevpage', $pt ), $q );
+			$out2 .= ' | ' . $prevLink;
+		}
+
+		if( $n == $this->maxPerPage && $s = $dbr->fetchObject($res) ) {
+			# $s is the first link of the next chunk
+			$t = Title::MakeTitle($namespace, $s->page_title);
 			$q = 'from=' . $t->getPartialUrl() . ( $namespace ? '&namespace=' . $namespace : '' );
 			$nextLink = $sk->makeKnownLinkObj( $self, wfMsgHtml( 'nextpage', $t->getText() ), $q );
 			$out2 .= ' | ' . $nextLink;
@@ -280,8 +315,15 @@ function showChunk( $namespace = NS_MAIN, $from, $including = false ) {
 	}
 
 	$wgOut->addHtml( $out2 . $out );
-	if( isset( $nextLink ) )
-		$wgOut->addHtml( '<p style="font-size: smaller; float: right;">' . $nextLink . '</p>' );
+	if( isset($prevLink) or isset($nextLink) ) {
+		$wgOut->addHtml( '<hr/><p style="font-size: smaller; float: right;">' );
+		if( isset( $prevLink ) )
+			$wgOut->addHTML( $prevLink . ' | ');
+		if( isset( $nextLink ) )
+			$wgOut->addHTML( $nextLink );
+		$wgOut->addHTML( '</p>' );
+
+	}
 	
 }
 	
diff --git a/languages/messages/MessagesEn.php b/languages/messages/MessagesEn.php
index d799fd06af..eac35cd45a 100644
--- a/languages/messages/MessagesEn.php
+++ b/languages/messages/MessagesEn.php
@@ -1525,6 +1525,7 @@ You can narrow down the view by selecting a log type, the user name, or the affe
 
 # Special:Allpages
 'nextpage'          => 'Next page ($1)',
+'prevpage'          => 'Previous page ($1)',
 'allpagesfrom'		=> 'Display pages starting at:',
 'allarticles'		=> 'All articles',
 'allinnamespace'	=> 'All pages ($1 namespace)',
-- 
2.20.1