Layers in EJ2 TypeScript Diagram control

16 Dec 202424 minutes to read

Layer organizes related shapes within a diagram control as named categories. Assigning shapes to different layers enables selective viewing, removal, and locking of distinct shape categories.

In a diagram, Layers facilitate the modification of properties for all shapes assigned to a specific layer. Key properties that can be configured include:

Objects
Visible
Lock
AddInfo

Objects

The layer’s objects property specifies which diagram elements belong to that layer. This property contains a collection where you can define the categories of nodes and connectors that the layer encompasses.

In the following example, the basic shapes are categorized in layer 1, and the flow shapes are categorized in layer 2.

index.ts
index.html
import { ConnectorModel, Diagram, NodeModel } from '@syncfusion/ej2-diagrams';
// A node is created and stored in nodes array.
let nodes: NodeModel[] = [
  // Layer 1 Nodes
  {
    id: 'node1',
    width: 100,
    height: 100,
    offsetX: 100,
    offsetY: 100,
    shape: { type: 'Basic', shape: 'Rectangle' },
    annotations: [{ content: 'Basic rectangle' }],
  },
  {
    id: 'node2',
    width: 100,
    height: 100,
    offsetX: 250,
    offsetY: 100,
    shape: { type: 'Basic', shape: 'Ellipse' },
    annotations: [{ content: 'Basic Ellipse' }],
  },
  {
    id: 'node3',
    width: 100,
    height: 100,
    offsetX: 400,
    offsetY: 100,
    shape: { type: 'Basic', shape: 'RightTriangle' },
    annotations: [{ content: 'Basic RightTriangle' }],
  },
  {
    id: 'node4',
    width: 100,
    height: 100,
    offsetX: 550,
    offsetY: 100,
    shape: { type: 'Basic', shape: 'Plus' },
    annotations: [{ content: 'Basic Plus' }],
  },

  // Layer 2 Nodes

  {
    id: 'node5',
    width: 100,
    height: 100,
    offsetX: 100,
    offsetY: 300,
    shape: { type: 'Flow', shape: 'Terminator' },
    annotations: [{ content: 'Flow Terminator' }],
  },
  {
    id: 'node6',
    width: 100,
    height: 100,
    offsetX: 250,
    offsetY: 300,
    shape: { type: 'Flow', shape: 'Process' },
    annotations: [{ content: 'Flow Process' }],
  },
  {
    id: 'node7',
    width: 100,
    height: 100,
    offsetX: 400,
    offsetY: 300,
    shape: { type: 'Flow', shape: 'Decision' },
    annotations: [{ content: 'Flow Decision' }],
  },
  {
    id: 'node8',
    width: 100,
    height: 100,
    offsetX: 550,
    offsetY: 300,
    shape: { type: 'Flow', shape: 'Document' },
    annotations: [{ content: 'Flow Document' }],
  },
];
// initialize Diagram component
let diagram: Diagram = new Diagram({
  width: '100%',
  height: '600px',
  nodes: nodes,
  layers: [
    {
      id: 'layer1',
      //Layer 1 objects
      objects: ['node1', 'node2', 'node3', 'node4'],
    },
    {
      id: 'layer2',
      //Layer 2 objects
      objects: ['node5', 'node6', 'node7', 'node8'],
    },
  ],
});
// render initialized Diagram
diagram.appendTo('#element');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>EJ2 Diagram</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-base/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-buttons/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-popups/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-splitbuttons/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-diagrams/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-navigations/styles/fabric.css" rel="stylesheet" />
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <div id='element'></div>
    </div>
</body>

</html>

Visible

The layer’s visible property is used to control the visibility of the elements assigned to the layer. You can hide objects in one layer while showing objects in another layer.

In the following example, the visibility of layer one is set to false. By default, the visible property of a layer is set to true.

index.ts
index.html
import { ConnectorModel, Diagram, NodeModel } from '@syncfusion/ej2-diagrams';
// A node is created and stored in nodes array.
let nodes: NodeModel[] = [
  {
    id: 'node1',
    width: 100,
    height: 100,
    offsetX: 100,
    offsetY: 100,
    annotations: [{ content: 'Layer 1 Object' }],
  },
  {
    id: 'node2',
    width: 100,
    height: 100,
    offsetX: 300,
    offsetY: 100,
    annotations: [{ content: 'Layer 2 Object' }],
  },
];
let connectors: ConnectorModel[] = [
  {
    id: 'connector1',
    type: 'Straight',
    sourcePoint: {
      x: 100,
      y: 300,
    },
    targetPoint: {
      x: 200,
      y: 400,
    },
    annotations: [{ content: 'Layer 2 Object' }],
  },
];
// initialize Diagram component
let diagram: Diagram = new Diagram({
  width: '100%',
  height: '600px',
  nodes: nodes,
  connectors: connectors,
  layers: [
    {
      id: 'layer1',
      //Layer 1 visibility set as false.
      visible: false,
      objects: ['node1'],
    },
    {
      id: 'layer2',
      visible: true,
      objects: ['node2', 'connector1'],
    },
  ],
});
// render initialized Diagram
diagram.appendTo('#element');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>EJ2 Diagram</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-base/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-buttons/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-popups/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-splitbuttons/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-diagrams/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-navigations/styles/fabric.css" rel="stylesheet" />
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <div id='element'></div>
    </div>
</body>

</html>

Lock

The layer’s lock property is used to prevent or allow changes to the element’s dimensions and positions. Locking a layer prevents any interactions with the objects in that layer, such as selecting, dragging, rotating, and connecting.

In the following example the objects in layer one is locked. By default, the lock property of a layer is set to false.

index.ts
index.html
import { ConnectorModel, Diagram, NodeModel } from '@syncfusion/ej2-diagrams';
// A node is created and stored in nodes array.
let nodes: NodeModel[] = [
  {
    id: 'node1',
    width: 100,
    height: 100,
    offsetX: 100,
    offsetY: 100,
    annotations: [{ content: 'Layer 1 Object Locked' }],
  },
  {
    id: 'node2',
    width: 100,
    height: 100,
    offsetX: 300,
    offsetY: 100,
    annotations: [{ content: 'Layer 2 Object' }],
  },
];
let connectors: ConnectorModel[] = [
  {
    id: 'connector1',
    type: 'Straight',
    sourcePoint: {
      x: 100,
      y: 300,
    },
    targetPoint: {
      x: 200,
      y: 400,
    },
    annotations: [{ content: 'Layer 2 Object' }],
  },
];
// initialize Diagram component
let diagram: Diagram = new Diagram({
  width: '100%',
  height: '600px',
  nodes: nodes,
  connectors: connectors,
  layers: [
    {
      id: 'layer1',
      visible: true,
      objects: ['node1'],
      //Locks the layer1 and prevents any interactions to the objects in layer1
      lock: true,
    },
    {
      id: 'layer2',
      visible: true,
      objects: ['node2', 'connector1'],
      lock: false,
    },
  ],
});
// render initialized Diagram
diagram.appendTo('#element');
<!DOCTYPE html>
<html lang="en">

<head>
    <title>EJ2 Diagram</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-base/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-buttons/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-popups/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-splitbuttons/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-diagrams/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-navigations/styles/fabric.css" rel="stylesheet" />
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <div id='element'></div>
    </div>
</body>

</html>

AddInfo

The addInfo property of layers allow you to maintain additional information to the layers.

The following code illustrates how to add additional information to the layers.

let nodes:NodeModel[] = [{
        id: 'node1',
        width: 100,
        height: 100,
        offsetX: 100,
        offsetY: 100,
    },
    {
        id: 'node2',
        width: 100,
        height: 100,
        offsetX: 300,
        offsetY: 100,
    }
];
let connectors:ConnectorModel[] = [{
    id: 'connector1',
    type: 'Straight',
    sourcePoint: {
        x: 100,
        y: 300
    },
    targetPoint: {
        x: 200,
        y: 400
    },
}];
//Additional informations of layer
let addInfo = { Description: 'Layer1' };
// initialize Diagram component
let diagram = new Diagram({
    width: '100%',
    height: '600px',
    connectors: connectors,
    nodes: nodes,
    layers: [{
            id: 'layer1',
            visible: true,
            objects: ['node1', 'node2'],
            addInfo: addInfo
        },
        {
            id: 'layer2',
            visible: true,
            objects: ['connector1']
        }
    ]
});

Add layer at runtime

Layers can be added at runtime using the addLayer public method.

The layer’s id property defines the ID of the layer, which is used to find the layer at runtime and apply any customizations. You can also add new objects to the new layer using the addLayer method.

The following code illustrates how to add a new layer with new connectors stored in an object array of the new layer:

index.ts
index.html
import { Diagram, NodeModel } from '@syncfusion/ej2-diagrams';
// A node is created and stored in nodes array.
let nodes: NodeModel[] = [
  // Layer 1 Nodes
  {
    id: 'node1',
    width: 100,
    height: 100,
    offsetX: 100,
    offsetY: 100,
    annotations: [{ content: 'Layer 1 Object' }],
  },

  // Layer 2 Nodes

  {
    id: 'node2',
    width: 100,
    height: 100,
    offsetX: 100,
    offsetY: 300,
    annotations: [{ content: 'Layer 2 Object' }],
  },
];
// initialize Diagram component
let diagram: Diagram = new Diagram({
  width: '100%',
  height: '600px',
  nodes: nodes,
  layers: [
    {
      id: 'layer1',
      //Layer 1 objects
      objects: ['node1'],
    },
    {
      id: 'layer2',
      //Layer 2 objects
      objects: ['node2'],
    },
  ],
});
// render initialized Diagram
diagram.appendTo('#element');

(document.getElementById('addLayer') as HTMLInputElement).onclick = () => {
  let newLayer = {
    id: 'newlayer',
    visible: true,
    lock: false,
  };
  let layerObject = [
    {
      id: 'con1',
      type: 'Straight',
      sourceID: 'node1',
      targetID: 'node2',
    },
  ];
  /**
   * Add the layers to the existing diagram layer collection
   * newLayer - representing the layer to be added to the diagram.
   * layerObject -  An optional array of objects associated with the layer.
   */
  diagram.addLayer(newLayer, layerObject);
};
<!DOCTYPE html>
<html lang="en">

<head>
    <title>EJ2 Diagram</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-base/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-buttons/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-popups/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-splitbuttons/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-diagrams/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-navigations/styles/fabric.css" rel="stylesheet" />
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <input type="button" value="addLayer" id="addLayer" />
        <div id='element'></div>
    </div>
</body>

</html>

Remove layer at runtime

Layers can be removed at runtime by using the removeLayer public method.

To remove a layer, pass the ID of the layer you want to remove as a parameter to the removeLayer method.

The following code illustrates how to remove a layer.

index.ts
index.html
import { ConnectorModel, Diagram, NodeModel } from '@syncfusion/ej2-diagrams';
// A node is created and stored in nodes array.
let nodes: NodeModel[] = [
  // Layer 1 Nodes
  {
    id: 'node1',
    width: 100,
    height: 100,
    offsetX: 100,
    offsetY: 100,
    annotations: [{ content: 'Layer 1 Object' }],
  },

  // Layer 2 Nodes

  {
    id: 'node2',
    width: 100,
    height: 100,
    offsetX: 100,
    offsetY: 300,
    annotations: [{ content: 'Layer 2 Object' }],
  },
];
// initialize Diagram component
let diagram: Diagram = new Diagram({
  width: '100%',
  height: '600px',
  nodes: nodes,
  layers: [
    {
      id: 'layer1',
      //Layer 1 objects
      objects: ['node1'],
    },
    {
      id: 'layer2',
      //Layer 2 objects
      objects: ['node2'],
    },
  ],
});
// render initialized Diagram
diagram.appendTo('#element');

(document.getElementById('removeLayer') as HTMLInputElement).onclick = () => {
    let layerId = 'layer1';
    /**
     * Remove the layer from the existing diagram layer collection
     * layerId - representing the id of the layer to be removed from the diagram.
     */
    diagram.removeLayer(layerId);
};
<!DOCTYPE html>
<html lang="en">

<head>
    <title>EJ2 Diagram</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-base/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-buttons/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-popups/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-splitbuttons/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-diagrams/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-navigations/styles/fabric.css" rel="stylesheet" />
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <input type="button" value="removeLayer" id="removeLayer" />
        <div id='element'></div>
    </div>
</body>

</html>

moveObjects

You can move objects from one layer to another dynamically using the moveObjects public method of the diagram control. This can be useful for managing complex diagrams with multiple layers where you need to update the categorization of elements based on user interaction or other dynamic conditions..

The following code illustrates how to move objects from one layer to another layer.

index.ts
index.html
import { Diagram, NodeModel } from '@syncfusion/ej2-diagrams';
// A node is created and stored in nodes array.
let nodes: NodeModel[] = [
  // Layer 1 Nodes
  {
    id: 'node1',
    width: 100,
    height: 100,
    offsetX: 100,
    offsetY: 100,
    annotations: [{ content: 'Layer 1 Object' }],
  },

  {
    id: 'node2',
    width: 100,
    height: 100,
    offsetX: 100,
    offsetY: 300,
    annotations: [{ content: 'Layer 1 Object' }],
  },

  // Layer 2 Nodes

  {
    id: 'node3',
    width: 100,
    height: 100,
    offsetX: 300,
    offsetY: 300,
    annotations: [{ content: 'Layer 2 Object' }],
  },
];
// initialize Diagram component
let diagram: Diagram = new Diagram({
  width: '100%',
  height: '600px',
  nodes: nodes,
  layers: [
    {
      id: 'layer1',
      //Layer 1 objects
      objects: ['node1', 'node2'],
    },
    {
      id: 'layer2',
      //Layer 2 objects
      objects: ['node3'],
    },
  ],
});
// render initialized Diagram
diagram.appendTo('#element');

(document.getElementById('moveObjects') as HTMLInputElement).onclick = () => {
  /**
   * Move objects from one layer to another layer
   * Parameter 1 - An array of object IDs represented as strings to be moved
   * parameter 2 -  The ID of the target layer to which the objects should be moved.
   */
  diagram.moveObjects(['node1'], 'layer2');
};
<!DOCTYPE html>
<html lang="en">

<head>
    <title>EJ2 Diagram</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-base/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-buttons/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-popups/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-splitbuttons/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-diagrams/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-navigations/styles/fabric.css" rel="stylesheet" />
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <input type="button" value="moveObjects" id="moveObjects" />
        <div id='element'></div>
    </div>
</body>

</html>

Z-Index

zIndex property of a layer defines its Z order within the diagram. This property allows you to control the layer’s position in the stacking order. You can adjust the layer’s z-index by moving it forward or backward relative to other layers in the diagram.

Bring Layer Forward

Layers can be moved forward at runtime by using the bringLayerForward public method.

// move the layer forward
diagram.bringLayerForward('layer1');

Send Layer Backward

Layers can be moved backward at runtime by using the sendLayerBackward public method.

// move the layer backward
diagram.sendLayerBackward('layer1');

The following code illustrates how to send the layer forward/backward to another layer.

index.ts
index.html
import { Diagram, NodeModel } from '@syncfusion/ej2-diagrams';
// A node is created and stored in nodes array.
let nodes: NodeModel[] = [
  // Layer 1 Nodes
  {
    id: 'node1',
    width: 100,
    height: 100,
    offsetX: 100,
    offsetY: 100,
    annotations: [{ content: 'Layer 1 Object' }],
  },

  {
    id: 'node2',
    width: 100,
    height: 100,
    offsetX: 130,
    offsetY: 130,
    annotations: [{ content: 'Layer 2 Object' }],
  },

  // Layer 2 Nodes

  {
    id: 'node3',
    width: 100,
    height: 100,
    offsetX: 160,
    offsetY: 160,
    annotations: [{ content: 'Layer 3 Object' }],
  },
];
// initialize Diagram component
let diagram: Diagram = new Diagram({
  width: '100%',
  height: '600px',
  nodes: nodes,
  layers: [
    {
      id: 'layer1',
      //Layer 1 objects
      objects: ['node1'],
    },
    {
      id: 'layer2',
      //Layer 2 objects
      objects: ['node2'],
    },
    {
      id: 'layer3',
      //Layer 2 objects
      objects: ['node3'],
    },
  ],
});
// render initialized Diagram
diagram.appendTo('#element');

(document.getElementById('bringLayerForward') as HTMLInputElement).onclick =
  () => {
    /**
     * Move the layer forward
     * Parameter 1 -A string representing the id of the layer to be moved forward.
     */
    diagram.bringLayerForward('layer1');
  };

(document.getElementById('sendLayerBackward') as HTMLInputElement).onclick =
  () => {
    /**
     * Move the layer Backward
     * Parameter 1 - A string representing the id of the layer to be  moved backward.
     */
    diagram.sendLayerBackward('layer1');
  };
<!DOCTYPE html>
<html lang="en">

<head>
    <title>EJ2 Diagram</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-base/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-buttons/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-popups/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-splitbuttons/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-diagrams/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-navigations/styles/fabric.css" rel="stylesheet" />
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <input
        type="button"
        value="bringLayerForward"
        id="bringLayerForward"
      />
      <input
      type="button"
      value="sendLayerBackward"
      id="sendLayerBackward"
    />
        <div id='element'></div>
    </div>
</body>

</html>

Layer and objects rendering order

The rendering of diagram elements with layer properties involves grouping them within a diagram_diagramLayer for basic shape nodes and diagram_nativeLayer_svg for SVG-native elements. Even if different types of nodes are added within the same layer, the rendering at the DOM level occurs in separate layers. Therefore, when executing layering commands like bringLayerForward and sendLayerBackward, the native SVG elements will always render above the basic shape elements.

The order of rendering is as follows: HTML shapes -> SVG shapes -> Path data shapes & Basic shapes.

Clone Layer

Layers can be cloned with its object by using the cloneLayer public method.

The following code illustrates how to clone the layer.

index.ts
index.html
import { Diagram, NodeModel } from '@syncfusion/ej2-diagrams';
// A node is created and stored in nodes array.
let nodes: NodeModel[] = [
  // Layer 1 Nodes
  {
    id: 'node1',
    width: 100,
    height: 100,
    offsetX: 100,
    offsetY: 100,
    annotations: [{ content: 'Layer 1 Object' }],
  },

  {
    id: 'node2',
    width: 100,
    height: 100,
    offsetX: 300,
    offsetY: 130,
    annotations: [{ content: 'Layer 1 Object' }],
  },

  // Layer 2 Nodes

  {
    id: 'node3',
    width: 100,
    height: 100,
    offsetX: 160,
    offsetY: 360,
    annotations: [{ content: 'Layer 2 Object' }],
  },
];
// initialize Diagram component
let diagram: Diagram = new Diagram({
  width: '100%',
  height: '600px',
  nodes: nodes,
  layers: [
    {
      id: 'layer1',
      //Layer 1 objects
      objects: ['node1', 'node2'],
    },
    {
      id: 'layer2',
      //Layer 2 objects
      objects: ['node3'],
    },
  ],
});
// render initialized Diagram
diagram.appendTo('#element');

(document.getElementById('cloneLayer') as HTMLInputElement).onclick = () => {
  /**
   * To Clone the layer
   * Parameter 1 - A string representing the name of the layer to be cloned.
   */
  diagram.cloneLayer('layer1');
};
<!DOCTYPE html>
<html lang="en">

<head>
    <title>EJ2 Diagram</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Typescript UI Controls" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-base/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-buttons/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-popups/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-splitbuttons/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-diagrams/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/29.1.33/ej2-navigations/styles/fabric.css" rel="stylesheet" />
    <script src="systemjs.config.js"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <input type="button" value="cloneLayer" id="cloneLayer" />
        <div id='element'></div>
    </div>
</body>

</html>

Active layer

Active Layer refers to the layer with the highest z-index in a diagram compared to other layers. When adding objects at runtime, they are stored in this active layer. If no layers are explicitly defined in the diagram, a default layer is created and automatically set as the active layer. However, when multiple layers are defined, the layer with the highest z-index takes precedence as the active layer.

Public methods are available to get and set the active layer, which are explained below.

Get ActiveLayer

Active layer of the diagram can be retrieved by using the getActiveLayer public method.

The following code illustrates how fetch active layer from the diagram

// gets the active layer of diagram
let activeLayer = diagram.getActiveLayer();

Set ActiveLayer

You can set any layer to be the active layer of the diagram by using the setActiveLayer public method.

The following code illustrates how to set active layer for diagram

// set the active layer
//@param layerName defines the name of the layer which is to be active layer
diagram.setActiveLayer('layer2');