Context menu in React Diagram component

30 Jan 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.

Customize context menu

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.

import * as React from "react";
import * as ReactDOM from "react-dom";
import { DiagramComponent, DiagramContextMenu, Inject } from "@syncfusion/ej2-react-diagrams";
//Initializes the connector
let connector = [{
        id: 'connector1',
        sourceID: 'node1',
        targetID: 'node2',
        type: 'Straight',
        style: {
            strokeColor: '#6BA5D7',
            fill: '#6BA5D7',
            strokeWidth: 2,
        },
        targetDecorator: {
            style: {
                fill: '#6BA5D7',
                strokeColor: '#6BA5D7'
            }
        }
    }];
//Initializes the nodes
let node = [{
        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'
                }
            }],
    }];
//Initializes the Diagram component
ReactDOM.render(<DiagramComponent id="diagram_contextmenu" width={'650px'} height={'350px'} nodes={node} connectors={connector} 
//Enables the context menu
contextMenuSettings={{
        show: true
    }}><Inject services={[DiagramContextMenu]}/>
    </DiagramComponent>, document.getElementById("diagram"));
import * as React from "react";
import * as ReactDOM from "react-dom";
import {
    Diagram,
    DiagramComponent,
    DiagramContextMenu,
    Inject,
    ConnectorModel,
    NodeModel,
    DiagramBeforeMenuOpenEventArgs
} from "@syncfusion/ej2-react-diagrams";
import {
    MenuEventArgs
} from '@syncfusion/ej2-navigations';
//Initializes the connector
let connector: ConnectorModel[] = [{
    id: 'connector1',
    sourceID: 'node1',
    targetID: 'node2',
    type: 'Straight',
    style: {
        strokeColor : '#6BA5D7',
        fill: '#6BA5D7',
        strokeWidth :  2,
    },
     targetDecorator: {
            style: {
                fill : '#6BA5D7',
                strokeColor :   '#6BA5D7'
            }
        }
}];
//Initializes the nodes
let node: NodeModel[] = [{
    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'
        }
    }],
}];
//Initializes the Diagram component
ReactDOM.render( <DiagramComponent id = "diagram_contextmenu"
    width = {
        '650px'
    }
    height = {
        '350px'
    }
    nodes = {
        node
    }
    connectors = {
        connector
    }
    //Enables the context menu
    contextMenuSettings = {
        {
            show: true
            }
        }
    ><Inject services = {[DiagramContextMenu]}/>
    </DiagramComponent>, document.getElementById("diagram")
);

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.

import * as React from "react";
import * as ReactDOM from "react-dom";
import { DiagramComponent, DiagramContextMenu, Inject } from "@syncfusion/ej2-react-diagrams";
//Initializes the connector
let connector = [{
        id: 'connector1',
        sourceID: 'node1',
        targetID: 'node2',
        type: 'Straight',
        style: {
            strokeColor: '#6BA5D7',
            fill: '#6BA5D7',
            strokeWidth: 2,
        },
        targetDecorator: {
            style: {
                fill: '#6BA5D7',
                strokeColor: '#6BA5D7'
            }
        }
    }];
//Initializes the nodes
let node = [{
        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'
                }
            }]
    }];
//Initializes the Diagram component
function App() {
    return (<DiagramComponent id="diagram_contextmenu" width={'650px'} height={'350px'} nodes={node} connectors={connector} contextMenuSettings={{
            //Enables the context menu
            show: true,
            // Defines the custom context menu items
            items: [
                {
                    // Text to be displayed
                    text: 'Save',
                    //Sets the id for the item
                    id: 'save',
                    //ContextMenu can be visible based on the target in which you open the ContextMenu.
                    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,
        }}>
      <Inject services={[DiagramContextMenu]}/>
    </DiagramComponent>);
}
const root = ReactDOM.createRoot(document.getElementById('diagram'));
root.render(<App />);
import * as React from "react";
import * as ReactDOM from "react-dom";
import {
    Diagram,
    DiagramComponent,
    DiagramContextMenu,
    Inject,
    ConnectorModel,
    NodeModel,
    DiagramBeforeMenuOpenEventArgs
} from "@syncfusion/ej2-react-diagrams";
import {
    MenuEventArgs
} from '@syncfusion/ej2-navigations';

//Initializes the connector
let connector: ConnectorModel[] = [{
    id: 'connector1',
    sourceID: 'node1',
    targetID: 'node2',
    type: 'Straight',
    style: {
        strokeColor : '#6BA5D7',
        fill: '#6BA5D7',
        strokeWidth :  2,
    },
    targetDecorator: {
            style: {
                fill : '#6BA5D7',
                strokeColor :   '#6BA5D7'
            }
        }
}];

//Initializes the nodes
let node: NodeModel[] = [{
    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'
        }
    }]
}];
//Initializes the Diagram component
function App() {
  return (
    <DiagramComponent
      id="diagram_contextmenu"
      width={'650px'}
      height={'350px'}
      nodes={node}
      connectors={connector}
      contextMenuSettings={{
        //Enables the context menu
        show: true,
        // Defines the custom context menu items
        items: [
          {
            // Text to be displayed
            text: 'Save',
            //Sets the id for the item
            id: 'save',
            //ContextMenu can be visible based on the target in which you open the ContextMenu.
            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,
      }}
    >
      <Inject services={[DiagramContextMenu]} />
    </DiagramComponent>
  );
}
const root = ReactDOM.createRoot(document.getElementById('diagram'));
root.render(<App />);

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

Template Support for Context menu

  • 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 Context Menu 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.

import * as React from "react";
import * as ReactDOM from "react-dom";
import { DiagramComponent, Inject, DiagramContextMenu } from "@syncfusion/ej2-react-diagrams";
let diagramInstance;
//Initializes the connector
let connector = [{
        id: 'connector1',
        sourceID: 'node1',
        targetID: 'node2',
        style: {
            strokeColor: '#6BA5D7',
            fill: '#6BA5D7',
            strokeWidth: 2,
        },
        targetDecorator: {
            style: {
                fill: '#6BA5D7',
                strokeColor: '#6BA5D7'
            }
        }
    }];
//Initializes the nodes
let node = [{
        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'
                }
            }]
    }];
//Initializes the Diagram component
function App() {
    return (<DiagramComponent id="diagram_contextmenu" ref={(diagram) => (diagramInstance = diagram)} width={'650px'} height={'350px'} nodes={node} connectors={connector} contextMenuSettings={{
            //Enables the context menu
            show: true,
            items: [
                {
                    text: 'Cut',
                    id: 'Cut',
                    target: '.e-diagramcontent',
                    iconCss: 'e-Cut',
                },
                {
                    text: 'Copy',
                    id: 'Copy',
                    target: '.e-diagramcontent',
                    iconCss: 'e-Copy',
                },
            ],
            //Shows the custom context menu items
            showCustomMenuOnly: true,
            contextMenuBeforeItemRender: function (args) {
                // To render template in li.
                let shortCutSpan = createElement('span');
                let text = args.item.text;
                let shortCutText = text === 'Cut'
                    ? 'Ctrl + S'
                    : text === 'Copy'
                        ? 'Ctrl + U'
                        : 'Ctrl + Shift + I';
                shortCutSpan.textContent = shortCutText;
                args.element.appendChild(shortCutSpan);
                shortCutSpan.setAttribute('class', 'shortcut');
            },
        }}>
      <Inject services={[DiagramContextMenu]}/>
    </DiagramComponent>);
}
const root = ReactDOM.createRoot(document.getElementById('diagram'));
root.render(<App />);
import * as React from "react";
import * as ReactDOM from "react-dom";
import {
    Diagram,
    DiagramComponent,
    Inject,
    DiagramContextMenu,
    MenuEventArgs,
    ConnectorModel,
    NodeModel
} from "@syncfusion/ej2-react-diagrams";
let diagramInstance: DiagramComponent;

//Initializes the connector
let connector: ConnectorModel[] = [{
    id: 'connector1',
    sourceID: 'node1',
    targetID: 'node2',
    style: {
        strokeColor : '#6BA5D7',
        fill: '#6BA5D7',
        strokeWidth :  2,
    },
    targetDecorator: {
        style: {
            fill : '#6BA5D7',
            strokeColor :   '#6BA5D7'
        }
    }
}];

//Initializes the nodes
let node: NodeModel[] = [{
    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'
        }
    }]
}];
//Initializes the Diagram component
function App() {
  return (
    <DiagramComponent
      id="diagram_contextmenu"
      ref={(diagram) => (diagramInstance = diagram)}
      width={'650px'}
      height={'350px'}
      nodes={node}
      connectors={connector}
      contextMenuSettings={{
        //Enables the context menu
        show: true,
        items: [
          {
            text: 'Cut',
            id: 'Cut',
            target: '.e-diagramcontent',
            iconCss: 'e-Cut',
          },
          {
            text: 'Copy',
            id: 'Copy',
            target: '.e-diagramcontent',
            iconCss: 'e-Copy',
          },
        ],
        //Shows the custom context menu items
        showCustomMenuOnly: true,
        contextMenuBeforeItemRender: function (args: MenuEventArgs) {
          // To render template in li.
          let shortCutSpan: HTMLElement = createElement('span');
          let text: string = args.item.text;
          let shortCutText: string =
            text === 'Cut'
              ? 'Ctrl + S'
              : text === 'Copy'
              ? 'Ctrl + U'
              : 'Ctrl + Shift + I';
          shortCutSpan.textContent = shortCutText;
          args.element.appendChild(shortCutSpan);
          shortCutSpan.setAttribute('class', 'shortcut');
        },
      }}
    >
      <Inject services={[DiagramContextMenu]} />
    </DiagramComponent>
  );
}
const root = ReactDOM.createRoot(document.getElementById('diagram'));
root.render(<App />);

Context menu events

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.

import * as React from "react";
import * as ReactDOM from "react-dom";
import { DiagramComponent, Inject, DiagramContextMenu } from "@syncfusion/ej2-react-diagrams";
let diagramInstance;
//Initializes the connector
let connector = [{
        id: 'connector1',
        sourceID: 'node1',
        targetID: 'node2',
        style: {
            strokeColor: '#6BA5D7',
            fill: '#6BA5D7',
            strokeWidth: 2,
        },
        targetDecorator: {
            style: {
                fill: '#6BA5D7',
                strokeColor: '#6BA5D7'
            }
        }
    }];
//Initializes the nodes
let node = [{
        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'
                }
            }]
    }];
//Initializes the Diagram component
function App() {
    return (<DiagramComponent id="diagram_contextmenu" ref={(diagram) => (diagramInstance = diagram)} width={'650px'} height={'350px'} nodes={node} connectors={connector} contextMenuSettings={{
            //Enables the context menu
            show: true,
            items: [
                {
                    text: 'delete',
                    id: 'delete',
                },
            ],
            // Hides the default context menu items
            showCustomMenuOnly: false,
        }} contextMenuOpen={(args) => {
            //do your custom action here.
            for (let item of args.items) {
                if (item.text === 'delete') {
                    if (!diagramInstance.selectedItems.nodes.length &&
                        !diagramInstance.selectedItems.connectors.length) {
                        args.hiddenItems.push(item.id);
                    }
                }
            }
        }} contextMenuClick={(args) => {
            //do your custom action here.
            if (args.item.text === 'delete') {
                if (diagramInstance.selectedItems.nodes.length +
                    diagramInstance.selectedItems.connectors.length >
                    0) {
                    diagramInstance.cut();
                }
            }
        }}>
      <Inject services={[DiagramContextMenu]}/>
    </DiagramComponent>);
}
const root = ReactDOM.createRoot(document.getElementById('diagram'));
root.render(<App />);
import * as React from "react";
import * as ReactDOM from "react-dom";
import {
    Diagram,
    DiagramComponent,
    Inject,
    DiagramContextMenu,
    DiagramBeforeMenuOpenEventArgs,
    ConnectorModel,
    NodeModel
} from "@syncfusion/ej2-react-diagrams";
import { MenuEventArgs } from '@syncfusion/ej2-navigations';

let diagramInstance: DiagramComponent;

//Initializes the connector
let connector: ConnectorModel[] = [{
    id: 'connector1',
    sourceID: 'node1',
    targetID: 'node2',
    style: {
        strokeColor : '#6BA5D7',
        fill: '#6BA5D7',
        strokeWidth :  2,
    },
    targetDecorator: {
            style: {
                fill : '#6BA5D7',
                strokeColor :   '#6BA5D7'
            }
        }
}];

//Initializes the nodes
let node: NodeModel[] = [{
    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'
        }
    }]
}];
//Initializes the Diagram component
function App() {
  return (
    <DiagramComponent
      id="diagram_contextmenu"
      ref={(diagram) => (diagramInstance = diagram)}
      width={'650px'}
      height={'350px'}
      nodes={node}
      connectors={connector}
      contextMenuSettings={{
        //Enables the context menu
        show: true,
        items: [
          {
            text: 'delete',
            id: 'delete',
          },
        ],
        // Hides the default context menu items
        showCustomMenuOnly: false,
      }}
      contextMenuOpen={(args) => {
        //do your custom action here.
        for (let item of args.items) {
          if (item.text === 'delete') {
            if (
              !diagramInstance.selectedItems.nodes.length &&
              !diagramInstance.selectedItems.connectors.length
            ) {
              args.hiddenItems.push(item.id);
            }
          }
        }
      }}
      contextMenuClick={(args) => {
        //do your custom action here.
        if (args.item.text === 'delete') {
          if (
            diagramInstance.selectedItems.nodes.length +
              diagramInstance.selectedItems.connectors.length >
            0
          ) {
            diagramInstance.cut();
          }
        }
      }}
    >
      <Inject services={[DiagramContextMenu]} />
    </DiagramComponent>
  );
}
const root = ReactDOM.createRoot(document.getElementById('diagram'));
root.render(<App />);