Labels in EJ2 JavaScript Diagram control

10 Feb 202424 minutes to read

Annotation is a block of text that can be displayed over a node or connector. Annotation is used to textually represent an object with a string that can be edited at runtime. Multiple annotations can be added to a node/connector.

Create annotation

An annotation can be added to a node/connector by defining the annotation object and adding that to the annotation collection of the node/connector. The content property of annotation defines the text to be displayed. The following code illustrates how to create a annotation.

index.js
index.html
var node = {
    id: 'node1',
    // Position of the node
    offsetX: 100,
    offsetY: 100,
    // Size of the node
    width: 100,
    height: 100,
    style: {
        fill: '#6BA5D7',
        strokeColor: 'white'
    },
    annotations: [{ template: '<div><input type="button" value="Submit"></div>' }]
        };

// initialize Diagram component

var diagram = new ej.diagrams.Diagram({
    width: '100%', height: '600px', nodes: [node]
    }, '#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">
    
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-buttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-popups/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-splitbuttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-diagrams/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-navigations/styles/fabric.css" rel="stylesheet">
    
<script src="https://cdn.syncfusion.com/ej2/25.1.35/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    
    <div id="container">
        <div id="element"></div>
    </div>


<script>
var ele = document.getElementById('container');
if(ele) {
  ele.style.visibility = "visible";
}   
      </script>
<script src="index.js" type="text/javascript"></script>
</body></html>

Add annotations at runtime

Annotations can be added at runtime by using the client-side method addLabels. The following code illustrates how to add a annotation to a node.
The annotation’s ID property is used to define the name of the annotation and its further used to find the annotation at runtime and do any customization.

index.js
index.html
var node = {
    // Position of the node
    offsetX: 250,
    offsetY: 250,
    // Size of the node
    width: 100,
    height: 100,
    style: { fill: '#6BA5D7', strokeColor: 'white' },
        };

// initialize Diagram component

var diagram = new ej.diagrams.Diagram({
    width: '100%', height: '600px', nodes: [node]
    });
diagram.appendTo('#element');
var annotation =  [{ id: 'label1', content: 'Annotation' }]
    diagram.addLabels(diagram.nodes[0], annotation);
    diagram.dataBind();
<!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">
    
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-buttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-popups/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-splitbuttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-diagrams/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-navigations/styles/fabric.css" rel="stylesheet">
    
<script src="https://cdn.syncfusion.com/ej2/25.1.35/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    
    <div id="container">
        <div id="element"></div>
    </div>


<script>
var ele = document.getElementById('container');
if(ele) {
  ele.style.visibility = "visible";
}   
      </script>
<script src="index.js" type="text/javascript"></script>
</body></html>

Remove annotation

A collection of annotations can be removed from the node by using client-side method removeLabels. The following code illustrates how to remove a annotation to a node.

index.js
index.html
var node = {
    // Position of the node
    offsetX: 250,
    offsetY: 250,
    // Size of the node
    width: 100,
    height: 100,
    sstyle: { fill: '#6BA5D7', strokeColor: 'white' },
    annotations: [{ content: 'Annotation' }]
        };

// initialize Diagram component

var diagram = new ej.diagrams.Diagram({
    width: '100%', height: '600px', nodes: [node]
    }, '#element');

diagram.nodes[0].annotations[0].content = 'Updated Annotation';
diagram.dataBind();
<!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">
    
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-buttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-popups/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-splitbuttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-diagrams/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-navigations/styles/fabric.css" rel="stylesheet">
    
<script src="https://cdn.syncfusion.com/ej2/25.1.35/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    
    <div id="container">
        <div id="element"></div>
    </div>


<script>
var ele = document.getElementById('container');
if(ele) {
  ele.style.visibility = "visible";
}   
      </script>
<script src="index.js" type="text/javascript"></script>
</body></html>

Update annotation at runtime

You can change any annotation properties at runtime and update it through the client-side method dataBind.

The following code example illustrates how to change the annotation properties.

index.js
index.html
var node = {
    // Position of the node
    offsetX: 250,
    offsetY: 250,
    // Size of the node
    width: 100,
    height: 100,
    sstyle: { fill: '#6BA5D7', strokeColor: 'white' },
    annotations: [{ content: 'Annotation' }]
        };

// initialize Diagram component

var diagram = new ej.diagrams.Diagram({
    width: '100%', height: '600px', nodes: [node]
    }, '#element');

diagram.nodes[0].annotations[0].content = 'Updated Annotation';
diagram.dataBind();
<!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">
    
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-buttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-popups/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-splitbuttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-diagrams/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-navigations/styles/fabric.css" rel="stylesheet">
    
<script src="https://cdn.syncfusion.com/ej2/25.1.35/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    
    <div id="container">
        <div id="element"></div>
    </div>


<script>
var ele = document.getElementById('container');
if(ele) {
  ele.style.visibility = "visible";
}   
      </script>
<script src="index.js" type="text/javascript"></script>
</body></html>

Alignment

Annotation can be aligned relative to the node boundaries. It has margin, offset, horizontal, and vertical alignment settings. It is quite tricky when all four alignments are used together but gives more control over alignment.

Offset

The offset property of annotation is used to align the annotations based on fractions. 0 represents top/left corner, 1 represents bottom/right corner, and 0.5 represents half of width/height.

Set the size for a nodes annotation by using width and height properties.

The following code shows the relationship between the annotation position (black color circle) and offset (fraction values).

index.js
index.html
var node = {
    // Position of the node
    offsetX: 250,
    offsetY: 250,
    // Size of the node
    width: 100,
    height: 100,
    sstyle: { fill: '#6BA5D7', strokeColor: 'white' },
    annotations: [{ content: 'Annotation' }]
        };

// initialize Diagram component

var diagram = new ej.diagrams.Diagram({
    width: '100%', height: '600px', nodes: [node]
    }, '#element');

diagram.nodes[0].annotations[0].content = 'Updated Annotation';
diagram.dataBind();
<!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">
    
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-buttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-popups/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-splitbuttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-diagrams/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-navigations/styles/fabric.css" rel="stylesheet">
    
<script src="https://cdn.syncfusion.com/ej2/25.1.35/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    
    <div id="container">
        <div id="element"></div>
    </div>


<script>
var ele = document.getElementById('container');
if(ele) {
  ele.style.visibility = "visible";
}   
      </script>
<script src="index.js" type="text/javascript"></script>
</body></html>

Horizontal and vertical alignment

The horizontalAlignment property of annotation is used to set how the annotation is horizontally aligned at the annotation position determined from the fraction values. The verticalAlignment property is used to set how annotation is vertically aligned at the annotation position.

The following tables illustrates all the possible alignments visually with ‘offset (0, 0)’.

Horizontal Alignment	Vertical Alignment	Output with Offset(0,0)
Left	Top
Center	Top
Right	Top
Left	Center
Center	Center
Right	Center
Left	Bottom
Center	Bottom
Right	Bottom

The following codes illustrates how to align annotations.

index.js
index.html
var node = {
    // Position of the node
    offsetX: 250,
    offsetY: 250,
    // Size of the node
    width: 100,
    height: 100,
    style: { fill: '#6BA5D7', strokeColor: 'white' },
    annotations: [{ content: 'Annotation',  horizontalAlignment: 'Left' , verticalAlignment: 'Top' }]
        };

// initialize Diagram component

var diagram = new ej.diagrams.Diagram({
    width: '100%', height: '600px', nodes: [node]
    }, '#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">
    
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-buttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-popups/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-splitbuttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-diagrams/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-navigations/styles/fabric.css" rel="stylesheet">
    
<script src="https://cdn.syncfusion.com/ej2/25.1.35/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    
    <div id="container">
        <div id="element"></div>
    </div>


<script>
var ele = document.getElementById('container');
if(ele) {
  ele.style.visibility = "visible";
}   
      </script>
<script src="index.js" type="text/javascript"></script>
</body></html>

Annotation alignment with respect to segments

The offset and alignment properties of annotation allows you to align the connector annotations with respect to the segments.

The following code example illustrates how to align connector annotations.

index.js
index.html
var node = {
    id: 'node1',
    // Position of the node
    offsetX: 100,
    offsetY: 100,
    // Size of the node
    width: 100,
    height: 100,
    style: { fill: '#6BA5D7', strokeColor: 'white' },
    annotations: [{ content: 'Task1' }]
};

var node2 = {
    id: 'node2',
    // Position of the node
    offsetX: 300,
    offsetY: 100,
    // Size of the node
    width: 100,
    height: 100,
    style: { fill: '#6BA5D7', strokeColor: 'white' },
    annotations: [{ content: 'Task2' }]
};

var connector = {
    sourceID: 'node1', targetID: 'node2' , type: 'Orthogonal', style: { strokeColor: '#6BA5D7', strokeWidth: 2 },
    annotations: [{ content: '0', offset: 0 }, { content: '1', offset: 1}]
};


// initialize Diagram component

var diagram = new ej.diagrams.Diagram({
    width: '100%', height: '600px', nodes: [node, node2], connectors: [connector]
    }, '#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">
    
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-buttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-popups/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-splitbuttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-diagrams/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-navigations/styles/fabric.css" rel="stylesheet">
    
<script src="https://cdn.syncfusion.com/ej2/25.1.35/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    
    <div id="container">
        <div id="element"></div>
    </div>


<script>
var ele = document.getElementById('container');
if(ele) {
  ele.style.visibility = "visible";
}   
      </script>
<script src="index.js" type="text/javascript"></script>
</body></html>

Margin

Margin is an absolute value used to add some blank space in any one of its four sides. The annotations can be displaced with the margin property. The following code example illustrates how to align a annotation based on its offset, horizontalAlignment, verticalAlignment, and margin values.

index.js
index.html
var nodes = [
    {
        id: 'Start', width: 100, height: 100, offsetX: 100, offsetY: 100,
         style: { fill: '#6BA5D7', strokeColor: 'white' },
    annotations: [{ content: 'Task1', margin: { top: 10}, horizontalAlignment: 'Center' , verticalAlignment: 'Top', offset: { x: 0.5, y: 1} }]
    },
];



// initialize Diagram component

var diagram = new ej.diagrams.Diagram({
    width: '100%', height: '600px', nodes: nodes
    }, '#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">
    
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-buttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-popups/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-splitbuttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-diagrams/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-navigations/styles/fabric.css" rel="stylesheet">
    
<script src="https://cdn.syncfusion.com/ej2/25.1.35/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    
    <div id="container">
        <div id="element"></div>
    </div>


<script>
var ele = document.getElementById('container');
if(ele) {
  ele.style.visibility = "visible";
}   
      </script>
<script src="index.js" type="text/javascript"></script>
</body></html>

Text align

The textAlign property of annotation allows you to set how the text should be aligned (left, right, center, or justify) inside the text block. The following codes illustrate how to set textAlign for an annotation.

index.js
index.html
var node = {
    // Position of the node
    offsetX: 100,
    offsetY: 100,
    // Size of the node
    width: 100,
    height: 100,
    style: { fill: '#6BA5D7', strokeColor: 'white' },
    annotations: [{ content: 'Text align is set as Left', style: {textAlign: 'Left'} }]
        };


var diagram = new ej.diagrams.Diagram({
    width: '100%', height: '600px', nodes: [node]
    }, '#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">
    
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-buttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-popups/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-splitbuttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-diagrams/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-navigations/styles/fabric.css" rel="stylesheet">
    
<script src="https://cdn.syncfusion.com/ej2/25.1.35/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    
    <div id="container">
        <div id="element"></div>
    </div>


<script>
var ele = document.getElementById('container');
if(ele) {
  ele.style.visibility = "visible";
}   
      </script>
<script src="index.js" type="text/javascript"></script>
</body></html>

Hyperlink

Diagram provides a support to add a hyperlink for the nodes/connectors annotation. It can also be customized.

A User can open the hyperlink in the new window, the same tab and the new tab by using the hyperlinkOpenState property

index.js
index.html
var node = {
    // Position of the node
    offsetX: 100,
    offsetY: 100,
    // Size of the node
    width: 100,
    height: 100,
    style: { fill: '#6BA5D7', strokeColor: 'white' },
    annotations: [{ hyperlink: { link: 'https://hr.syncfusion.com/home',hyperlinkOpenState:'CurrentTab' } }]
        };


var diagram = new ej.diagrams.Diagram({
    width: '100%', height: '600px', nodes: [node]
    }, '#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">
    
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-buttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-popups/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-splitbuttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-diagrams/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-navigations/styles/fabric.css" rel="stylesheet">
    
<script src="https://cdn.syncfusion.com/ej2/25.1.35/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    
    <div id="container">
        <div id="element"></div>
    </div>


<script>
var ele = document.getElementById('container');
if(ele) {
  ele.style.visibility = "visible";
}   
      </script>
<script src="index.js" type="text/javascript"></script>
</body></html>

Template Support for Annotation

Diagram provides template support for annotation. you should define a SVG/HTML content as string in the annotation’s template property.

The following code illustrates how to define a template in node’s annotation. similarly, you can define it in connectors.

index.js
index.html
var node = {
    id: 'node1',
    // Position of the node
    offsetX: 100,
    offsetY: 100,
    // Size of the node
    width: 100,
    height: 100,
    style: {
        fill: '#6BA5D7',
        strokeColor: 'white'
    },
    annotations: [{ template: '<div><input type="button" value="Submit"></div>' }]
        };

// initialize Diagram component

var diagram = new ej.diagrams.Diagram({
    width: '100%', height: '600px', nodes: [node]
    }, '#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">
    
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-buttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-popups/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-splitbuttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-diagrams/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-navigations/styles/fabric.css" rel="stylesheet">
    
<script src="https://cdn.syncfusion.com/ej2/25.1.35/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    
    <div id="container">
        <div id="element"></div>
    </div>


<script>
var ele = document.getElementById('container');
if(ele) {
  ele.style.visibility = "visible";
}   
      </script>
<script src="index.js" type="text/javascript"></script>
</body></html>

Wrapping

When text overflows node boundaries, you can control it by using text wrapping. So, it is wrapped into multiple lines. The wrapping property of annotation defines how the text should be wrapped. The following code illustrates how to wrap a text in a node.

index.js
index.html
var node = {
    // Position of the node
    offsetX: 100,
    offsetY: 100,
    // Size of the node
    width: 100,
    height: 100,
   style: { fill: '#6BA5D7', strokeColor: 'white' },
    annotations: [{ content: 'Annotation Text Wrapping',style: { textWrapping:'Wrap' } }]
        };


var diagram = new ej.diagrams.Diagram({
    width: '100%', height: '600px', nodes: [node]
    }, '#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">
    
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-buttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-popups/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-splitbuttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-diagrams/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-navigations/styles/fabric.css" rel="stylesheet">
    
<script src="https://cdn.syncfusion.com/ej2/25.1.35/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    
    <div id="container">
        <div id="element"></div>
    </div>


<script>
var ele = document.getElementById('container');
if(ele) {
  ele.style.visibility = "visible";
}   
      </script>
<script src="index.js" type="text/javascript"></script>
</body></html>

Value	Description	Image
No Wrap	Text will not be wrapped.
Wrap	Text-wrapping occurs, when the text overflows beyond the available node width.
WrapWithOverflow (Default)	Text-wrapping occurs, when the text overflows beyond the available node width. However, the text may overflow beyond the node width in the case of a very long word.

Text overflow

The label’s TextOverflow property is used control whether to display the overflowed content in node or not.

index.js
index.html
var node = {
    // Position of the node
    offsetX: 250,
    offsetY: 250,
    // Size of the node
    width: 100,
    height: 100,
    style: { fill: '#6BA5D7', strokeColor: 'white' },
    annotations: [{ content: 'Annotation Text',style: { textOverflow: 'Ellipsis' } }]
        };

// initialize Diagram component

var diagram = new ej.diagrams.Diagram({
    width: '100%', height: '600px', nodes: [node]
    }, '#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">
    
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-buttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-popups/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-splitbuttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-diagrams/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-navigations/styles/fabric.css" rel="stylesheet">
    
<script src="https://cdn.syncfusion.com/ej2/25.1.35/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    
    <div id="container">
        <div id="element"></div>
    </div>


<script>
var ele = document.getElementById('container');
if(ele) {
  ele.style.visibility = "visible";
}   
      </script>
<script src="index.js" type="text/javascript"></script>
</body></html>

Appearance

You can change the font style of the annotations with the font specific properties (fontSize, fontFamily, color). The following code illustrates how to customize the appearance of the annotation.
The label’s bold, italic, and textDecoration properties are used to style the label’s text.
The label’s fill, strokeColor, and strokeWidth properties are used to define the background color and border color of the annotation and the opacity property is used to define the transparency of the annotations.
The visible property of the annotation enables or disables the visibility of annotation.

index.js
index.html
var node = {
    // Position of the node
    offsetX: 250,
    offsetY: 250,
    // Size of the node
    width: 100,
    height: 100,
    style: { fill: '#6BA5D7', strokeColor: 'white' },
    annotations: [{ content: 'Annotation Text',style: { color: 'black', bold: true, italic: true, fontSize: '12', fontFamily: 'TimesNewRoman' } }]
        };

// initialize Diagram component

var diagram = new ej.diagrams.Diagram({
    width: '100%', height: '600px', nodes: [node]
    }, '#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">
    
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-buttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-popups/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-splitbuttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-diagrams/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-navigations/styles/fabric.css" rel="stylesheet">
    
<script src="https://cdn.syncfusion.com/ej2/25.1.35/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    
    <div id="container">
        <div id="element"></div>
    </div>


<script>
var ele = document.getElementById('container');
if(ele) {
  ele.style.visibility = "visible";
}   
      </script>
<script src="index.js" type="text/javascript"></script>
</body></html>

The fill, border, and opacity appearances of the text can also be customized with appearance specific properties of annotation. The following code illustrates how to customize background, opacity, and border of the annotation.

index.js
index.html
var node = {
    // Position of the node
    offsetX: 250,
    offsetY: 250,
    // Size of the node
    width: 100,
    height: 100,
    style: { fill: '#6BA5D7', strokeColor: 'white' },
    annotations: [{ content: 'Annotation Text',style: { color: 'black', fill: 'white', opacity: 0.7 , strokeColor: 'black', strokeWidth: 2 }}]
};

// initialize Diagram component

var diagram = new ej.diagrams.Diagram({
    width: '100%', height: '600px', nodes: [node]
    }, '#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">
    
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-buttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-popups/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-splitbuttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-diagrams/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-navigations/styles/fabric.css" rel="stylesheet">
    
<script src="https://cdn.syncfusion.com/ej2/25.1.35/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    
    <div id="container">
        <div id="element"></div>
    </div>


<script>
var ele = document.getElementById('container');
if(ele) {
  ele.style.visibility = "visible";
}   
      </script>
<script src="index.js" type="text/javascript"></script>
</body></html>

Interaction

Diagram allows annotation to be interacted by selecting, dragging, rotating, and resizing. Annotation interaction is disabled, by default. You can enable annotation interaction with the constraints property of annotation. You can also curtail the services of interaction by enabling either selecting, dragging, rotating, or resizing individually with the respective constraints property of annotation. The following code illustrates how to enable annotation interaction.

index.js
index.html
var node = {
    // Position of the node
    offsetX: 250,
    offsetY: 250,
    // Size of the node
    width: 100,
    height: 100,
    style: { fill: '#6BA5D7', strokeColor: 'white' },
    annotations: [{ content: 'Annotation Text',  constraints: ej.diagrams.AnnotationConstraints.ReadOnly}]
        };

// initialize Diagram component

var diagram = new ej.diagrams.Diagram({
    width: '100%', height: '600px', nodes: [node]
    }, '#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">
    
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-buttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-popups/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-splitbuttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-diagrams/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-navigations/styles/fabric.css" rel="stylesheet">
    
<script src="https://cdn.syncfusion.com/ej2/25.1.35/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    
    <div id="container">
        <div id="element"></div>
    </div>


<script>
var ele = document.getElementById('container');
if(ele) {
  ele.style.visibility = "visible";
}   
      </script>
<script src="index.js" type="text/javascript"></script>
</body></html>

Edit

Diagram provides support to edit an annotation at runtime, either programmatically or interactively. By default, annotation is in view mode. But it can be brought to edit mode in two ways;

Programmatically
By using startTextEdit method, edit the text through programmatically.
Interactively
1. By double-clicking the annotation.
2. By selecting the item and pressing the F2 key.

Double-clicking any annotation will enables editing and the node enables first annotation editing. When the focus of editor is lost, the annotation for the node is updated. When you double-click on the node/connector/diagram model, the doubleClick event gets triggered.

Read-only annotations

Diagram allows to create read-only annotations. You have to set the read-only property of annotation to enable/disable the read-only constraints. The following code illustrates how to enable read-only mode.

index.js
index.html
var node = {
    // Position of the node
    offsetX: 250,
    offsetY: 250,
    // Size of the node
    width: 100,
    height: 100,
    style: { fill: '#6BA5D7', strokeColor: 'white' },
    annotations: [{ content: 'Annotation Text',  constraints: ej.diagrams.AnnotationConstraints.ReadOnly}]
        };

// initialize Diagram component

var diagram = new ej.diagrams.Diagram({
    width: '100%', height: '600px', nodes: [node]
    }, '#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">
    
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-buttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-popups/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-splitbuttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-diagrams/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-navigations/styles/fabric.css" rel="stylesheet">
    
<script src="https://cdn.syncfusion.com/ej2/25.1.35/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    
    <div id="container">
        <div id="element"></div>
    </div>


<script>
var ele = document.getElementById('container');
if(ele) {
  ele.style.visibility = "visible";
}   
      </script>
<script src="index.js" type="text/javascript"></script>
</body></html>

Drag Limit

The diagram control now supports defining the dragLimit to the label while dragging from the connector and also update the position to the nearest segment offset.
You can set the value to dragLimit left, right, top, and bottom properties which allow the dragging of connector labels to a certain limit based on the user defined values.
By default, drag limit will be disabled for the connector. It can be enabled by setting connector constraints as drag.
The following code illustrates how to set a dragLimit for connector annotations.

index.js
index.html
var connector = {
     id: 'connector', type: 'Orthogonal',
        sourcePoint: { x: 200, y: 200 },
        targetPoint: { x: 300, y: 300 },
        annotations: [
            {
                content: 'connector1', offset: 0.5,
                constraints: ej.diagrams.AnnotationConstraints.Interaction | ej.diagrams.AnnotationConstraints.Drag,
                dragLimit: { left: 20, right: 20, top: 20, bottom: 20 }
            }
        ]
        };

// initialize Diagram component

var diagram = new ej.diagrams.Diagram({
    width: '100%', height: '600px', connectors: [connector]
    }, '#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">
    
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-buttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-popups/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-splitbuttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-diagrams/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-navigations/styles/fabric.css" rel="stylesheet">
    
<script src="https://cdn.syncfusion.com/ej2/25.1.35/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    
    <div id="container">
        <div id="element"></div>
    </div>


<script>
var ele = document.getElementById('container');
if(ele) {
  ele.style.visibility = "visible";
}   
      </script>
<script src="index.js" type="text/javascript"></script>
</body></html>

Multiple annotations

You can add any number of annotations to a node or connector. The following code illustrates how to add multiple annotations to a node.

index.js
index.html
var node = {
    // Position of the node
    offsetX: 250,
    offsetY: 250,
    // Size of the node
    width: 100,
    height: 100,
    style: { fill: '#6BA5D7', strokeColor: 'white' },
     annotations: [{ content: 'Left', offset: { x: 0.12, y: 0.1 }},
    { content: 'Center', offset: { x: 0.5, y: 0.5 } },
    { content: 'Right', offset: { x: 0.82, y: 0.9 } }]
};

// initialize Diagram component

var diagram = new ej.diagrams.Diagram({
    width: '100%', height: '600px', nodes: [node]
    }, '#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">
    
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-buttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-popups/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-splitbuttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-diagrams/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-navigations/styles/fabric.css" rel="stylesheet">
    
<script src="https://cdn.syncfusion.com/ej2/25.1.35/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>

<body>
    
    <div id="container">
        <div id="element"></div>
    </div>


<script>
var ele = document.getElementById('container');
if(ele) {
  ele.style.visibility = "visible";
}   
      </script>
<script src="index.js" type="text/javascript"></script>
</body></html>

Constraints

The constraints property of annotation allows you to enable/disable certain annotation behaviors. For instance, you can disable annotation editing.