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

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

Used to capture the event when drag node to collapsed parent node, zTree based on return value to determine whether to auto expand parent node.

Default: null

### Function Parameter Descriptions

#### treeId String

zTree unique identifier: treeId, easy for users to control.

#### treeNode JSON

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