Consider config option useheading before reading the rest.

It will replace underscores in links in wikipages. When people copy this linktitles on a page and use them in their internallinks, that's fine, because DokuWiki interpret spaces as underscores.

Modify only indicated lines.

Index: inc/parser/renderer.php
===================================================================
--- inc/parser/renderer.php
+++ inc/parser/renderer.php
 
     function _simpleTitle($name){
         global $conf;
 
         //if there is a hash we use the ancor name only
         list($name,$hash) = explode('#',$name,2);
         if($hash) return $hash;
 
         if($conf['useslash']){
             $name = strtr($name,';/',';:');
         }else{
             $name = strtr($name,';',':');
         }
 
-        return noNSorNS($name);
+        $name = noNSorNS($name);
+
+        // replace '_' with ' '
+        return strtr($name,'_',' ');
     }

Thanks for the great tips on this page! I wanted a few things for my titles: to replace underscores by spaces, add an initial capital and show an abbreviated title when using namespaces. I disliked the idea of using Useheading, so this is what I did:

Add this at the bottom of inc/template.php:

function format_pretty_ref($name){
    if(strstr($name, ':') == ''){
	return utf8_ucfirst(strtr($name,'_',' '));
    }else{
        return utf8_ucfirst(substr(strrchr(strtr($name,'_',' '), ':'), 1 ));
    }
}

Wrap the function around tpl_pagetitle in lib/tpl/[yourtheme]/main.php or add it to tpl_pagetitle in inc/template.php
eg. print(format_pretty_ref(tpl_pagetitle($ID,true)))

e.g. 'wiki:namespace:page_title' becomes 'Page title'

– jayjay 2008-05-08

This one may even be better. The standard start page of a namespace is 'namespace:start'. The above code will show 'Start' as the pagetitle of every namespace start page. The code below will show the namespace title instead of the word 'start'.

eg. 'wine_bottles:french_wine' becomes 'French wine' ; 'wine_bottles:start' becomes 'Wine bottles'

function format_pretty_ref($name){
global $conf;
if(strstr($name, ':') == ''){
	return utf8_ucfirst(strtr($name,'_',' '));
}else{
	if(substr(strrchr($name, ':'), 1 ) == $conf['start']) {
	  $name = substr($name, 0, strlen($name) - strlen($conf['start']) - 1);
	  if(strstr($name, ':') == ''){
		return utf8_ucfirst(strtr($name,'_',' '));
	  }else{
		return utf8_ucfirst(substr(strrchr(strtr($name,'_',' '), ':'), 1 ));
	  }
	}else{
	  return utf8_ucfirst(substr(strrchr(strtr($name,'_',' '), ':'), 1 ));
	}
  }
}

– jayjay 2008-05-08

function format_pretty_ref($name){
  return utf8_ucwords(str_replace(":", " | ", strtr($name,'_',' ')));
}