showUrl MODX

showUrl.plugin.php

<?php
/**
 * Plugin to add a read only "url" field to the document tab
 *
 * @var modX $modx
 * @var array $scriptProperties
 *
 * @event OnDocFormPrerender
 */
if(!$resource || !$mode || $modx == "new") return;
$url = $modx->makeUrl($resource->id, $resource->context_key, '', 'full'); 
$modx->controller->addHtml("
<script> 

    // We are targeting the left column in the resource tab
    Ext.ComponentMgr.onAvailable('modx-resource-main-left', function(left) {
        left.on('beforerender', function() {
            // page is a reference to the whole form panel
            var page = Ext.getCmp('modx-panel-resource')
                // record is a reference to our resource fields
                ,record = page.record
            ;
            
            // Add new url filed on
            left.add({
                xtype: 'textfield'
                ,name: 'previewurl'
                ,value: '".$url."'
                ,anchor: '100%'
                ,layout: 'anchor'
                ,fieldLabel: 'URL'
		,readOnly: true
            });
        })
    });
    
</script>");