Elements Tab in Tree

gistfile1.php

//<?php
//OnManagerTreePrerender,OnManagerTreeRender
//Autor: Dmi3yy
//Version:  0.1 

if($_SESSION['mgrRole']=='1') {
	$e = &$modx->Event;
	if($e->name == 'OnManagerTreePrerender'){
		$output = '
		<style>
		#treePane .tab-page UL
{
	margin: 0;
	padding: 0;
}
#treePane .tab-page UL LI
{
	list-style: none;
	padding-left: 0;
}
#treePane .tab-page UL LI LI
{
	list-style: circle inside;
	padding-left: 5px;
}
#treePane .tab {padding: 5px 5px;}

.ext-ico {text-decoration:none!important;color:#97D19C!important;}
		</style>
		<div class="tab-pane" id="treePane" style="border:0">
		 <script type="text/javascript" src="media/script/tabpane.js"></script>
		<script type="text/javascript">
      		treePane = new WebFXTabPane(document.getElementById( "treePane" ),true);
    	</script>
		 <div class="tab-page" id="tabDoc" style="padding-left:0; padding-right:0;">
			<h2 class="tab"><strong>Doc</strong></h2>
			<script type="text/javascript">treePane.addTabPage( document.getElementById( "tabDoc" ) );</script>
			
			
		
		
		';
		$e->output($output);
	}
	if($e->name == 'OnManagerTreeRender'){
		//global $modx;
		$tablePre = $modx->db->config['dbase'] . '.`' . $modx->db->config['table_prefix'];
		function createResourceList($resourceTable,$action,$tablePre,$nameField = 'name') {
			global $modx, $_lang;
			$output = '<ul>';
			
			$pluginsql = $resourceTable == 'site_plugins' ? $tablePre.$resourceTable.'`.disabled, ' : '';
			$tvsql = $resourceTable == 'site_tmplvars' ? $tablePre.$resourceTable.'`.caption, ' : '';
			
			//$orderby = $resourceTable == 'site_plugins' ? '6,2' : '5,1';
			
			if ($resourceTable == 'site_plugins' || $resourceTable == 'site_tmplvars') {
				$orderby= '6,2';
			}else{
				$orderby= '5,1';
			}
			
			
			$sql = 'SELECT '.$pluginsql.$tvsql.$tablePre.$resourceTable.'`.'.$nameField.' as name, '.$tablePre.$resourceTable.'`.id, '.$tablePre.$resourceTable.'`.description, '.$tablePre.$resourceTable.'`.locked, if(isnull('.$tablePre.'categories`.category),\''.$_lang['no_category'].'\','.$tablePre.'categories`.category) as category FROM '.$tablePre.$resourceTable.'` left join '.$tablePre.'categories` on '.$tablePre.$resourceTable.'`.category = '.$tablePre.'categories`.id ORDER BY '.$orderby;
			
			$rs = $modx->db->query($sql);
			$limit = $modx->db->getRecordCount($rs);
			if($limit<1){
				echo $_lang['no_results'];
			}
			$preCat = '';
			$insideUl = 0;
			for($i=0; $i<$limit; $i++) {
				$row = $modx->db->getRow($rs);
				$row['category'] = stripslashes($row['category']); //pixelchutes
				if ($preCat !== $row['category']) {
					$output .= $insideUl? '</ul>': '';
					$output .= '<li><strong>'.$row['category'].'</strong><ul>';
					$insideUl = 1;
				}
				
				if ($resourceTable == 'site_plugins') $class = $row['disabled'] ? ' class="disabledPlugin"' : '';
				$output .= '<li><span'.$class.'><a href="index.php?id='.$row['id'].'&amp;a='.$action.'" target="main">'.$row['name'].' <small>(' . $row['id'] . ')</small></a>
				
				<a class="ext-ico" href="#" title="Управление элементами" onclick="window.open(\'index.php?id='.$row['id'].'&a='.$action.'\',\'gener\',\'width=800,height=600,top=\'+((screen.height-600)/2)+\',left=\'+((screen.width-800)/2)+\',toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=yes,resizable=no\')"><sup>nw</sup></a>'.($modx_textdir ? '&rlm;' : '').'</span>';
				
				/*
				//@TODO: add description as title to link
				if ($resourceTable == 'site_tmplvars') {
					$output .= !empty($row['description']) ? ' - '.$row['caption'].' &nbsp; <small>  ('.$row['description'].')</small>' : ' - '.$row['caption'];
				}else{
					$output .= !empty($row['description']) ? ' - '.$row['description'] : '' ;
				}*/
				$output .= $row['locked'] ? ' <em>('.$_lang['locked'].')</em>' : "" ;
				$output .= '</li>';
				
				$preCat = $row['category'];
			}
			$output .= $insideUl? '</ul>': '';
			$output .= '</ul>';
			return $output;
		}
		
		$temp =  createResourceList('site_templates',16,$tablePre,'templatename');
		$tv =  createResourceList('site_tmplvars',301,$tablePre);
		$chunk =  createResourceList('site_htmlsnippets',78,$tablePre);
		$snippet =  createResourceList('site_snippets',22,$tablePre);
		$plugin =  createResourceList('site_plugins',102,$tablePre);
		
		$output = '	
			</div>
			
			<div class="tab-page" id="tabTemp" style="padding-left:0; padding-right:0;">
				<h2 class="tab"><strong>Tpl</strong></h2>
				<script type="text/javascript">treePane.addTabPage( document.getElementById( "tabTemp" ) );</script>
				'.$temp.'
				
				<br/>
				<ul class="actionButtons">
           			 <li><a href="index.php?a=19" target="main">Новый шаблон</a></li>
					  <li><a href="javascript:location.reload();"><img src="media/style/'.$modx->config['manager_theme']. '/images/icons/refresh.png"/></a></li>
        		</ul>
			</div>
			
			<div class="tab-page" id="tabTV" style="padding-left:0; padding-right:0;">
				<h2 class="tab"><strong>TV</strong></h2>
				<script type="text/javascript">treePane.addTabPage( document.getElementById( "tabTV" ) );</script>
				'.$tv.'
				
				<br/>
				<ul class="actionButtons">
           			 <li><a href="index.php?a=300" target="main">Новый TV</a></li>
					  <li><a href="javascript:location.reload();"><img src="media/style/'.$modx->config['manager_theme']. '/images/icons/refresh.png"/></a></li>
        		</ul>
			</div>
			
			<div class="tab-page" id="tabCH" style="padding-left:0; padding-right:0;">
				<h2 class="tab"><strong>Ch</strong></h2>
				<script type="text/javascript">treePane.addTabPage( document.getElementById( "tabCH" ) );</script>
				'.$chunk.'
				
				<br/>
				<ul class="actionButtons">
           			 <li><a href="index.php?a=77" target="main">Новый чанк</a></li>
					  <li><a href="javascript:location.reload();"><img src="media/style/'.$modx->config['manager_theme']. '/images/icons/refresh.png"/></a></li>
        		</ul>
			</div>
			
			<div class="tab-page" id="tabSN" style="padding-left:0; padding-right:0;">
				<h2 class="tab"><strong>Sn</strong></h2>
				<script type="text/javascript">treePane.addTabPage( document.getElementById( "tabSN" ) );</script>
				'.$snippet.'
				
				<br/>
				<ul class="actionButtons">
           			 <li><a href="index.php?a=23" target="main">Новый сниппет</a></li>
					  <li><a href="javascript:location.reload();"><img src="media/style/'.$modx->config['manager_theme']. '/images/icons/refresh.png"/></a></li>
        		</ul>
			</div>
			
			<div class="tab-page" id="tabPL" style="padding-left:0; padding-right:0;">
				<h2 class="tab"><strong>Pl</strong></h2>
				<script type="text/javascript">treePane.addTabPage( document.getElementById( "tabPL" ) );</script>
				'.$plugin.'
				
				<br/>
				<ul class="actionButtons">
           			 <li><a href="index.php?a=101" target="main">Новый плагин</a></li>
					  <li><a href="javascript:location.reload();"><img src="media/style/'.$modx->config['manager_theme']. '/images/icons/refresh.png"/></a></li>
        		</ul>
			</div>
			<!-- @TODO: добавить возможность управления файлами 
			<div class="tab-page" id="tabFL" style="padding-left:0; padding-right:0;">
				<h2 class="tab"><strong>Fl</strong></h2>
				<script type="text/javascript">treePane.addTabPage( document.getElementById( "tabFL" ) );</script>
				тут будет дерево файлов
			</div>-->
			
		</div>';
		$e->output($output);
	}
}

Very cool plugin! Should go to the MODX core. Meanwhile I've modified it a little to use MODX hasPermission. Now it displays Templates tab if user can edit templates, Chunks tab if he can edit chunks and so on. https://gist.github.com/pmfx/884210dfdd8f49319f9aa6fb9ef3d7ba