Function(treeId, treeNodes, targetNode, moveType, isCopy)setting.callback.beforeDrop

Overview[ depends on jquery.ztree.exedit js ]

Specify callback function to be called before drag-drop of a node, The return value controls the execution of drag-drop callback.

Default: null

When a node is dropped, if the drop is not in a valid location, this callback will not be triggered, and will revert to the original position.

Function Parameter Descriptions

treeIdString

zTree unique identifier: treeId, the id of the containing tree.

treeNodesArray(JSON)

A collection of the nodes which has been dragged

The treeNodes which have been dragged, when copying nodes or moving nodes.

targetNodeJSON

JSON data object of the destination node on which treeNodes are being dropped.

If the treeNodes is the root node, the targetNode = null

moveTypeString

the relative position of move to the target node

"inner": will be child of targetNode

"prev": will be sibling node, and be in front of targetNode

"next": will be sibling node, and be behind targetNode

isCopyBoolean

the flag used to determine if the drop is to copy or move the node

true: copy node; false: move node

Return Boolean

return true or false

If return false, zTree will restore the dragged nodes, and will not trigger the 'onDrop' callback.

Examples of setting & function

1. disable to drag nodes to root

function myBeforeDrop(treeId, treeNodes, targetNode, moveType) {
    return !(targetNode == null || (moveType != "inner" && !targetNode.parentTId));
};
var setting = {
	edit: {
		enable: true
	},
	callback: {
		beforeDrop: myBeforeDrop
	}
};
......