How to prevent deletion of node or connector in JavaScript Diagram using Delete constraints?

This article explains how to prevent the deletion of a node or connector in a JavaScript Diagram using delete constraints. In the Syncfusion® JavaScript Diagram, by using NodeConstraints and ConnectorConstraints, we can enable or disable certain features of nodes and connectors.

To prevent the deletion of a node or connector in a Diagram using delete constraints, set the constraints as follows for nodes and connectors.

//set constraints as delete for Node
constraints: ej.diagrams.NodeConstraints.Default & ~ej.diagrams.NodeConstraints.Delete


var nodes =
[
   {
       id: "heptagon",
       offsetX: 100,
       offsetY: 160,
       width: 80,
       height: 80,
       constraints: ej.diagrams.NodeConstraints.Default & ~ej.diagrams.NodeConstraints.Delete
   },
];

//set constraints as delete for connector
constraints: ej.diagrams.ConnectorConstraints.Default & ~ej.diagrams.ConnectorConstraints.Delete,
var connectors =
[
   {
       id: "select",
       type: 'Orthogonal',
       constraints: ej.diagrams.ConnectorConstraints.Default & ~ej.diagrams.ConnectorConstraints.Delete,
       sourcePoint: {
           x: 200,
           y: 150
       },
       targetPoint: {
           x: 320,
           y: 250
       }
   },
];

Refer to the working sample for additional details and implementation: Sample

Conclusion

We hope you enjoyed learning about how to prevent the deletion of a node or connector in a JavaScript Diagram using delete constraints.

You can refer to our JavaScript Diagram feature tour page to learn about its other groundbreaking feature representations and documentation to quickly get started with configuration specifications. You can also explore our JavaScript Diagram example to understand how to create and manipulate data.
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