[Jean le Chauve]

J'ai modifié le code, il devrait t'être plus compréhensible (+ de classes).
Essaye de le comprendre puis pose tes questions.

Code :

[== Indéfini ==]
{if $count > 0}
    <nav class="navbar navbar-fixed-top" id="menutop">
        <div class="navbar-inner">
            <div class="container"><h1 class="brand" >Nom du projet</h1>
            {* 1er niveau de menu ds son ul *}    
                <ul class="nav">
                {foreach $nodelist as $node}
                    {capture class assign=class}index{$node->index} lev{$node->depth} prevLev{$node->prevdepth}{/capture}
                    {capture title assign=title}{$node->pagetitle}{if $node->titleattribute neq ""}, - {$node->titleattribute}{/if}{/capture}
                    {if $node->depth > $node->prevdepth}{* on est au moins ul>ul node->depth *}    
                        {if $node->depth > 2}
                            {repeat string='<ul class="dropdown-menu submenu">' times=$node->depth-$node->prevdepth}
                        {else}
                            {repeat string='<ul class="dropdown-menu">' times=$node->depth-$node->prevdepth}
                        {/if}
                        {elseif $node->depth < $node->prevdepth}{* si on descend de niveau *}
                        {repeat string='</li></ul>' times=$node->prevdepth-$node->depth}    
                        {elseif $node->index > 0}
                            </li>{* si on reste sur le même niveau que l'élément précédent}
                        {/if}
                    {/if}
                    {if $node->first == true}{* si on est sur le 1er élément d'un niveau, on concatène $class avec 'first' *}
                        {capture class assign=class}{$class|cat:" first"}{/capture}
                    {/if}
                    {if $node->last == true}{* si on est sur le dernier élément d'un niveau, on concatène $class avec 'last' *}
                        {capture class assign=class}{$class|cat:" last"}{/capture}
                    {/if}
                    {if $node->haschildren == true and $node->type != 'sectionheader' and $node->type != 'separator'}
                        {capture class assign=class}{$class|cat:" haschildren dropdown"}{/capture}
                        <li class='{$class}'><a rel="tooltip" href="{$node->url}" data-toggle="dropdown" title="{$title}">{$node->menutext}  <b></b></a>
                    {elseif $node->type == 'sectionheader'}
                        <li class='{$class}'><a rel="tooltip" href="{$node->url}" data-toggle="dropdown" title="{$title}">{$node->menutext} <b></b></a>
                    {else}
                        <li class='{$class}'><a rel="tooltip" href="{$node->url}" title="{$title}">{$node->menutext}</a>
                    {/if}
                {/foreach}
                        {repeat string="</li></ul>" times=$node->depth-1}
                    </li>
                </ul>
            </div>
        </div>
    </nav>
{/if}