This sample app demonstrates node drag and drop operations within DevExtreme TreeView when using a hierarchical data structure. You can reorder nodes within a single tree view or drag and drop nodes between two separate tree views.
Allow users to reorder nodes
Wrap the TreeView in a Sortable and enable the Sortable's allowReordering property.
Allow users to change node hierarchy
Enable the allowDropInsideItem property so that users can drop one node onto another. This adds it as the target node's child. If this property is disabled, users can only drop nodes between other nodes.
Allow users to drag only tree view nodes
To specify tree view nodes as drag targets, set the filter property to a class selector. Since all tree view nodes use the
dx-treeview-node class, you can use this class selector as needed.
Prevent a node from being moved into its child node
When a user moves a parent node into its own child node, it breaks the hierarchy. To prevent this outcome, implement the onDragChange function and traverse up the node tree. If the target is a child of the dragged node,
cancel the ability to drop the node.
Reorder nodes in code
Implement the onDragEnd function. In this function, you must gather information about nodes being moved. With this information, you can reorder the nodes in the data source (see the
moveNode function), and reassign the data source to the TreeView's items property.
Specify tree view identifiers (for drag and drop between multiple tree views only)
Identifiers help distinguish between multiple tree views. Save them in the Sortable's data property. The tree views below include the following identifiers: "driveC" and "driveD".
Combine tree views into one drag and drop group (for drag and drop between multiple tree views only)
Set the Sortable's group property to the same value for all tree views. This allows users to move nodes between the tree views.