## String treeNode.iconOpen

### Overview[ depends on jquery.ztree.core js ]

URL path of parent node's custom icon when it is expanded.

1. Only parent node support this attribute.

2. This attribute must be used simultaneously with 'iconClose' attribute.

3. If you need to use css to set the custom icon, please set the 'treeNode.iconSkin' attribute.

Default: undefined

### String Format

Icon image url can be a relative path or absolute path.

If use a relative path, please note the relationship between icon image and the page, ensure the correct image path.

### Examples of treeNode

#### 1. Set the custom icon

    var nodes = [
    	//Only show one icon when it is expanded or collapsed.
    	{ name:"Parent Node 1", icon:"/img/parent.gif"},

    	//Show two icons when it is expanded or collapsed.
    	{ name:"Parent Node 2", iconOpen:"/img/open.gif", iconClose:"/img/close.gif"},

    	//the custom icon for leaf node
    	{ name:"Leaf Node", icon:"/img/leaf.gif"}
    ]