如何为尚未显示的节点设置CSS类？

Question

I am using a Dijit Tree, and I need to change the CSS style for a node based on its item property.

The following code fails if the node has not been displayed yet (ie node is undefined) :

var node = this.tree.getNodesByItem(item);
if (node[0]) {
  domClass.toggle(node[0].domNode, className, add);
}

Is there any event that tells if a node is being displayed/has been created ?

Answer 1

If node is undefined when not yet displayed, that variable should be falsy and thus a simple logical AND ( && ) guard within your if -statement should suffice:

var node = this.tree.getNodesByItem(item);
if (node && node[0]) {
  domClass.toggle(node[0].domNode, className, add);
}