Adding next & previous links for same node type, translation-aware
description
This snippet adds a custom next_prev_same_type function to your theme template.php.
This allows you to insert Next and Previous links in your *.tpl.php file.
This function selects previous/next items depending on the time the node was created with a single query.
Only published nodes of the same node type like the current node are selected.
If the next/previous node id retrieved from the database is one of the current nodes' translations,
next_prev_same_type runs again to skip that node. In this case, there will be a new sql query.
Step 1 of 2
Insert this code into your template.php
<?php
function next_prev_same_type($nid=null, $path=null, $direction=null)
{
if($nid){
// gather some node information
$node = node_load($nid);
$type = $node->type;
$created = $node->created;
// retrieve all node ids of this nodes' translations
$translation_ids = array();
foreach($node->translation as $translation) {
if($translation->status == 1){
$translation_ids[$key] = $translation->nid;
}
}
// switch some vars depending on direction
switch ($direction){
case 'next':
$modifier = ">";
$order = "ASC";
$link_str = "Next project ›";
break;
case 'prev':
default:
$modifier = "<";
$order = "DESC";
$link_str = "‹ Previous project";
}
// get next / prev element from database
$query = db_query('select nid from {node} where type=\'%s\' AND status=1 AND nid!=%d AND created'.$modifier.'%d ORDER BY created %s, nid %s Limit 1',$type,$nid,$created,$order,$order);
while ($item = db_fetch_object($query)){
if($item->nid!=$nid && !in_array($item->nid,$translation_ids)){
$nav_nid = $item->nid;
}else{
// skip element, if it is a translation of the current node
return next_prev_same_type($item->nid,$path,$direction);
}
}
if($nav_nid){
return l(t($link_str),$path."/".$nav_nid);;
}
}
}
?>Step 2 of 2
Insert the code below somewhere in your *.tpl.php file (node.tpl.php, view_xyz.tpl.php, ...)
<?php
$next = next_prev_same_type($node->nid, "your/path/here", "next");
$prev = next_prev_same_type($node->nid, "yout/path/here", "prev");
if($prev!= FALSE){
$links[] = $prev;
}
if($next!= FALSE){
$links[] = $next;
}
print theme_links($links, $delimiter = ' ')
?>OR
<?php
print next_prev_same_type($node->nid, "your/path/here", "next");
print next_prev_same_type($node->nid, "yout/path/here", "prev");
?>Format as desired.
function variables
next_prev_same_type($nid=null, $path=null, $direction=null)
$nid is the current node
$path is the path to be used in the link
$direction is either 'next' or 'prev'
Notes
- Once the function is placed in your template.php, it can be run on any page, template, block, ...
- Add your comments below. Any ideas or modifications are welcome.