Themes

I hope this explains what you are asking, of course you could simplify this using $preg_replace
but that's another ball game.

This is the file name:

block_settings_renderer.php

And this is the contents...

<?php

require_once($CFG->dirroot. '/blocks/settings/renderer.php');

class theme_clean_block_settings_renderer extends block_settings_renderer {

    /**
     * Build the navigation node.
     *
     * @param navigation_node $node the navigation node object.
     * @param array $attrs list of attributes.
     * @param int $depth the depth, default to 1.
     * @return string the navigation node code.
     */
    protected function navigation_node(navigation_node $node, $attrs=array(), $depth = 1) {
        $items = $node->children;

        // exit if empty, we don't want an empty ul element
        if ($items->count()==0) {
            return '';
        }

        // array of nested li elements
        $lis = array();
        $number = 0;
        foreach ($items as $item) {
            $number++;
            if (!$item->display) {
                continue;
            }

            $isbranch = ($item->children->count()>0  || $item->nodetype==navigation_node::NODETYPE_BRANCH);
            $hasicon = (!$isbranch && $item->icon instanceof renderable);

            if ($isbranch) {
                $item->hideicon = true;
            }
            
           if ($item->get_content() == get_string('backup')) {
               $item->remove();
         }         
            $content = $this->output->render($item);

            // this applies to the li item which contains all child lists too
            $liclasses = array($item->get_css_type());
            $liexpandable = array();
            if ($isbranch) {
                $liclasses[] = 'contains_branch';
                if (!$item->forceopen || (!$item->forceopen && $item->collapse) || ($item->children->count() == 0
                        && $item->nodetype == navigation_node::NODETYPE_BRANCH)) {
                    $liexpandable = array('aria-expanded' => 'false');
                } else {
                    $liexpandable = array('aria-expanded' => 'true');
                }
                if ($item->requiresajaxloading) {
                    $liexpandable['data-requires-ajax'] = 'true';
                    $liexpandable['data-loaded'] = 'false';
                }

            } else if ($hasicon) {
                $liclasses[] = 'item_with_icon';
            }
            if ($item->isactive === true) {
                $liclasses[] = 'current_branch';
            }
            $nodetextid = 'label_' . $depth . '_' . $number;
            $liattr = array('class' => join(' ', $liclasses), 'tabindex' => '-1', 'role' => 'treeitem') + $liexpandable;
            // class attribute on the div item which only contains the item content
            $divclasses = array('tree_item');
            if ($isbranch) {
                $divclasses[] = 'branch';
            } else {
                $divclasses[] = 'leaf';
            }
            if (!empty($item->classes) && count($item->classes)>0) {
                $divclasses[] = join(' ', $item->classes);
            }
            $divattr = array('class'=>join(' ', $divclasses));
            if (!empty($item->id)) {
                $divattr['id'] = $item->id;
            }
            $content = html_writer::tag('p', $content, $divattr) . $this->navigation_node($item, array(), $depth + 1);
            if (!empty($item->preceedwithhr) && $item->preceedwithhr===true) {
                $content = html_writer::empty_tag('hr') . $content;
            }
            $liattr['aria-labelledby'] = $nodetextid;
            $content = html_writer::tag('li', $content, $liattr);
            $lis[] = $content;
        }

        if (count($lis)) {
            if (empty($attrs['role'])) {
                $attrs['role'] = 'group';
            }
            return html_writer::tag('ul', implode("\n", $lis), $attrs);
        } else {
            return '';
        }
    }
}