Context menu in EJ2 JavaScript Diagram control

18 Apr 202324 minutes to read

In graphical user interface (GUI), a context menu is a type of menu that appears when you perform right-click operation. Nested level of context menu items can be created. Diagram provides some in-built context menu items and allows to define custom menu items through the contextMenuSettings property.

The show property helps you to enable/disable the context menu. Diagram provides some default context menu items to ease the execution of some frequently used commands. The following code illustrates how to enable the default context menu items.

index.js
index.html
var nodes = [{
        id: 'node1',
        width: 100,
        height: 100,
        offsetX: 100,
        offsetY: 100,
        style: {
            fill:   '#6BA5D7',
            strokeColor: 'white',
            strokeWidth: 1
        },
        annotations: [{
            id: 'label1',
            content: 'Rectangle1',
            offset: {
                x: 0.5,
                y: 0.5
            },
            style: {
                color: 'white'
            }
        }]
    },
    {
        id: 'node2',
        width: 100,
        height: 100,
        offsetX: 300,
        offsetY: 100,
        style: {
            fill:   '#6BA5D7',
            strokeColor: 'white',
            strokeWidth: 1
        },
        annotations: [{
            id: 'label2',
            content: 'Rectangle2',
            offset: {
                x: 0.5,
                y: 0.5
            },
            style: {
                color: 'white'
            }
        }]
    },
];
var connector = {
    id: 'connector1',
    sourceID: 'node1',
    targetID: 'node2',
    type: 'Straight',
    style: {
        strokeColor : '#6BA5D7',
        fill: '#6BA5D7',
        strokeWidth :  2,
        targetDecorator: {
            style: {
                fill : '#6BA5D7',
                strokeColor :   '#6BA5D7'
            }
        }
    }
};
var diagram = new ej.diagrams.Diagram({
    width: '100%',
    height: '350px',
    nodes: nodes,
    connectors: [connector],
    //Enables the context menu
    contextMenuSettings: {
        show: true,
    }

}, '#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/ej2/23.2.4/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-buttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-popups/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-splitbuttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-diagrams/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-navigations/styles/fabric.css" rel="stylesheet">
    
<script src="https://cdn.syncfusion.com/ej2/23.2.4/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>

Context menu can be defined for individual node with the desired context menu items.

Apart from the default context menu items, define some additional context menu items. Those additional items have to be defined and added to the items property of the context menu.
Set text and ID for context menu item using the context menu text and ID properties respectively.
Set an image for the context menu item using the context menu url property.
The iconCss property defines the class/multiple classes separated by a space for the menu item that is used to include an icon. Menu item can include font icon and sprite image.
The target property used to set the target to show the menu item.
The separator property defines the horizontal lines that are used to separate the menu items. You cannot select the separators. You can enable separators to group the menu items using the separator property.

The following code example illustrates how to add custom context menu items.

index.js
index.html
var nodes = [{
        id: 'node1',
        width: 100,
        height: 100,
        offsetX: 100,
        offsetY: 100,
        style: {
            fill:   '#6BA5D7',
            strokeColor: 'white',
            strokeWidth: 1
        },
        annotations: [{
            id: 'label1',
            content: 'Rectangle1',
            offset: {
                x: 0.5,
                y: 0.5
            },
            style: {
                color: 'white'
            }
        }]
    },
    {
        id: 'node2',
        width: 100,
        height: 100,
        offsetX: 300,
        offsetY: 100,
        style: {
            fill:   '#6BA5D7',
            strokeColor: 'white',
            strokeWidth: 1
        },
        annotations: [{
            id: 'label2',
            content: 'Rectangle2',
            offset: {
                x: 0.5,
                y: 0.5
            },
            style: {
                color: 'white'
            }
        }]
    },
];
var connector = {
    id: 'connector1',
    sourceID: 'node1',
    targetID: 'node2',
    type: 'Straight',
    style: {
        strokeColor : '#6BA5D7',
        fill: '#6BA5D7',
        strokeWidth :  2,
        targetDecorator: {
            style: {
                fill : '#6BA5D7',
                strokeColor :   '#6BA5D7'
            }
        }
    }
};
var diagram = new ej.diagrams.Diagram({
    width: '100%',
    height: '350px',
    nodes: nodes,
    connectors: [connector],
    contextMenuSettings: {
        //Enables the context menu
        show: true,
        // Defines the custom context menu items
        items: [{
                // Text to be displayed
                text: 'Save',
                id: 'save',
                target: '.e-elementcontent',
                // Sets the css icons for the item
                iconCss: 'e-save'
            },
            {
                text: 'Load',
                id: 'load',
                target: '.e-elementcontent',
                iconCss: 'e-load'
            },
            {
                text: 'Clear',
                id: 'clear',
                target: '.e-elementcontent',
                iconCss: 'e-clear'
            }
        ],
        // Hides the default context menu items
        showCustomMenuOnly: false,
    }

}, '#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/ej2/23.2.4/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-buttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-popups/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-splitbuttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-diagrams/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-navigations/styles/fabric.css" rel="stylesheet">
    
<script src="https://cdn.syncfusion.com/ej2/23.2.4/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>

To display the custom context menu items alone, set the showCustomMenuOnly property to true.

Diagram provides template support for context menu. The context menu items can be customized by using the contextMenuBeforeItemRender event. The contextMenuBeforeItemRender event triggers while rendering each menu item.
In the following sample, the menu item is rendered with key code for specified action in ContextMenu using the template. Here, the key code is specified for the cut and copy at right corner of the menu items by adding a span element in the contextMenuBeforeItemRender event.

index.js
index.html
var nodes = [{
        id: 'node1',
        width: 100,
        height: 100,
        offsetX: 100,
        offsetY: 100,
        style: {
            fill:   '#6BA5D7',
            strokeColor: 'white',
            strokeWidth: 1
        },
        annotations: [{
            id: 'label1',
            content: 'Rectangle1',
            offset: {
                x: 0.5,
                y: 0.5
            },
            style: {
                color: 'white'
            }
        }]
    },
    {
        id: 'node2',
        width: 100,
        height: 100,
        offsetX: 300,
        offsetY: 100,
        style: {
            fill:   '#6BA5D7',
            strokeColor: 'white',
            strokeWidth: 1
        },
        annotations: [{
            id: 'label2',
            content: 'Rectangle2',
            offset: {
                x: 0.5,
                y: 0.5
            },
            style: {
                color: 'white'
            }
        }]
    },
];
var connector = {
    id: 'connector1',
    sourceID: 'node1',
    targetID: 'node2',
    type: 'Straight',
    style: {
        strokeColor : '#6BA5D7',
        fill: '#6BA5D7',
        strokeWidth :  2,
        targetDecorator: {
            style: {
                fill : '#6BA5D7',
                strokeColor :   '#6BA5D7'
            }
        }
    }
};
var diagram = new ej.diagrams.Diagram({
    width: '100%',
    height: '350px',
    nodes: nodes,
    connectors: [connector],
    contextMenuSettings: {
        //Enables the context menu
        show: true,
        items: [{
            text: 'delete',
            id: 'delete'
        }],
        // Hides the default context menu items
        showCustomMenuOnly: false,
    },
    contextMenuOpen: function(args) {
        //do your custom action here.
        for (let item of args.items) {
            if (item.text === 'delete') {
                if (!diagram.selectedItems.nodes.length && !diagram.selectedItems.connectors.length) {
                    args.hiddenItems.push(item.text);
                }
            }
        }
    },
    contextMenuClick: function(args) {
        //do your custom action here.
        if (args.item.id === 'delete') {
            if ((diagram.selectedItems.nodes.length + diagram.selectedItems.connectors.length) > 0) {
                diagram.cut();
            }
        }
    }

}, '#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/ej2/23.2.4/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-buttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-popups/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-splitbuttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-diagrams/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-navigations/styles/fabric.css" rel="stylesheet">
    
<script src="https://cdn.syncfusion.com/ej2/23.2.4/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>

You would be notified with events, when you try to open the context menu items contextMenuOpen and when you click the menu items contextMenuClick.The following code example illustrates how to define those events.

index.js
index.html
var nodes = [{
        id: 'node1',
        width: 100,
        height: 100,
        offsetX: 100,
        offsetY: 100,
        style: {
            fill:   '#6BA5D7',
            strokeColor: 'white',
            strokeWidth: 1
        },
        annotations: [{
            id: 'label1',
            content: 'Rectangle1',
            offset: {
                x: 0.5,
                y: 0.5
            },
            style: {
                color: 'white'
            }
        }]
    },
    {
        id: 'node2',
        width: 100,
        height: 100,
        offsetX: 300,
        offsetY: 100,
        style: {
            fill:   '#6BA5D7',
            strokeColor: 'white',
            strokeWidth: 1
        },
        annotations: [{
            id: 'label2',
            content: 'Rectangle2',
            offset: {
                x: 0.5,
                y: 0.5
            },
            style: {
                color: 'white'
            }
        }]
    },
];
var connector = {
    id: 'connector1',
    sourceID: 'node1',
    targetID: 'node2',
    type: 'Straight',
    style: {
        strokeColor : '#6BA5D7',
        fill: '#6BA5D7',
        strokeWidth :  2,
        targetDecorator: {
            style: {
                fill : '#6BA5D7',
                strokeColor :   '#6BA5D7'
            }
        }
    }
};
var diagram = new ej.diagrams.Diagram({
    width: '100%',
    height: '350px',
    nodes: nodes,
    connectors: [connector],
    contextMenuSettings: {
        //Enables the context menu
        show: true,
        items: [{
            text: 'delete',
            id: 'delete'
        }],
        // Hides the default context menu items
        showCustomMenuOnly: false,
    },
    contextMenuOpen: function(args) {
        //do your custom action here.
        for (let item of args.items) {
            if (item.text === 'delete') {
                if (!diagram.selectedItems.nodes.length && !diagram.selectedItems.connectors.length) {
                    args.hiddenItems.push(item.text);
                }
            }
        }
    },
    contextMenuClick: function(args) {
        //do your custom action here.
        if (args.item.id === 'delete') {
            if ((diagram.selectedItems.nodes.length + diagram.selectedItems.connectors.length) > 0) {
                diagram.cut();
            }
        }
    }

}, '#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/ej2/23.2.4/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-buttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-popups/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-splitbuttons/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-diagrams/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/23.2.4/ej2-navigations/styles/fabric.css" rel="stylesheet">
    
<script src="https://cdn.syncfusion.com/ej2/23.2.4/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>

Context menu in EJ2 JavaScript Diagram control

Customize context menu

Template Support for Context menu

Context menu events