## Function(treeId, treeNode)setting.callback.beforeDragOpen

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

Callback executed before drag node to collapsed parent node, The return value controls the auto expand behaviour of the parent node.

Default: null

### Function Parameter Descriptions

#### treeIdString

zTree unique identifier: treeId, the tree is what the treeNode(parent node) is belong to.

#### treeNodeJSON

JSON data object of the parent node which will be auto expanded

#### Return Boolean

return true or false

If return false, zTree will not auto expand parent node.

### Examples of setting & function

#### 1. disable to auto expand parent node.

    function myBeforeDragOpen(treeId, treeNode) {
        return false;
    };
    var setting = {
    	edit: {
    		enable: true
    	},
    	callback: {
    		beforeDragOpen: myBeforeDragOpen
    	}
    };
    ......