manager/templates/default/element/tv/renders/input/textarea.tpl
<textarea id="tv{$tv->id}" name="tv{$tv->id}" rows="15">{$tv->get('value')|escape}</textarea>
<script>
// <![CDATA[
{literal}
Ext.onReady(function() {
var fld = MODx.load({
{/literal}
xtype: 'textarea'
,applyTo: 'tv{$tv->id}'
,value: '{$tv->get('value')|escape:'javascript'}'
,height: 140
,width: '99%'
,enableKeyEvents: true
,msgTarget: 'under'
,allowBlank: {if $params.allowBlank == 1 || $params.allowBlank == 'true'}true{else}false{/if}
{literal}
,listeners: { 'keydown': { fn:MODx.fireResourceFormChange, scope:this}}
});
MODx.makeDroppable(fld);
Ext.getCmp('modx-panel-resource').getForm().add(fld);
});
{/literal}
// ]]>
</script>