Establish connection when a node is dropped on a connector

$("#DiagramContent").ejDiagram({
    drop: drop,
    connectors: [
        {
            name: "Link1", segments: [{ type: "orthogonal" }], sourcePoint: { x: 0, y: 0 }, targetPoint: { x: 40, y: 40 }, targetDecorator: { shape: "arrow" }, lineWidth: 2,
            //enable Allow drop on the connector.
            constraints: ej.datavisualization.Diagram.ConnectorConstraints.Default | ej.datavisualization.Diagram.ConnectorConstraints.AllowDrop,
        }
    ]
})
 
function drop(args) {
    var diagram = $("#DiagramContent").ejDiagram("instance");
    if (args.target.type === "connector") {
        //set the node as targetnode if connector already has source node.
        if (args.target.sourceNode) {
            diagram.updateConnector(args.target.name, { targetNode: args.element.name });
        }
        //set the node as sourcenode if connector already has target node.
        else if (args.target.targetNode) {
            diagram.updateConnector(args.target.name, { sourceNode: args.element.name });
        }
        //set the node as source/target node if connector dont have both source/target node.
        else if (!(args.target.sourceNode && args.target.targetNode)) {
            diagram.updateConnector(args.target.name, { sourceNode: args.element.name });
        }
    }
}