Ports in React Diagram component

8 Dec 202324 minutes to read

Diagram provides support to define custom ports for making connections.

Port

When a connector is connected between two nodes, its end points are automatically docked to the node’s nearest boundary as shown in the following image.

Port to Port

Ports act as the connection points of the node and allows to create connections with only those specific points as shown in the following image.

Port Image

Create port

Add ports when initializing nodes

To add a connection port, define the port object and add it to node’s ports collection. The offset property of port accepts an object of fractions and used to determine the position of ports. The following code illustrates how to add ports when initializing the node.

import * as React from "react";
import * as ReactDOM from "react-dom";
import {
    Diagram,
    DiagramComponent,
    NodeModel,
    PortVisibility
} from "@syncfusion/ej2-react-diagrams";
// A node is created and stored in nodes array.
let node: NodeModel[] = [{
    // Position of the node
    offsetX: 250,
    offsetY: 250,
    // Size of the node
    width: 100,
    height: 100,
    style: {
        fill: '#6BA5D7',
        strokeColor: 'white'
    },
    // Initialize port collection
    ports: [{
        // Sets the position for the port
        offset: {
            x: 0.5,
            y: 0.5
        },
        visibility: PortVisibility.Visible
    }]
}];
// initialize Diagram component
function App() {
  return (
    <DiagramComponent
      id="container"
      width={'100%'}
      height={'600px'}
      // Add node
      nodes={node}
      // render initialized Diagram
    />
  );
}
const root = ReactDOM.createRoot(document.getElementById('diagram'));
root.render(<App />);

Add ports at runtime

Add ports at runtime by using the client-side method addPorts. The following code illustrates how to add ports to node at runtime.

The port’s ID property is used to define the unique ID for the port and its further used to find the port at runtime.
If ID is not set, then default ID is automatically set.

import * as React from "react";
import * as ReactDOM from "react-dom";
import {
    Diagram,
    DiagramComponent,
    NodeModel,
    PointPortModel,
    PortVisibility
} from "@syncfusion/ej2-react-diagrams";
let diagramInstance:DiagramComponent;
// A node is created and stored in nodes array.
let node: NodeModel[] = [{
    // Position of the node
    offsetX: 250,
    offsetY: 250,
    // Size of the node
    width: 100,
    height: 100,
    style: {
        fill: '#6BA5D7',
        strokeColor: 'white'
    },
}];
// Initialize port collection
let port: PointPortModel[] = [{
        id: 'port1',
        offset: {
            x: 0,
            y: 0.5
        },
        visibility: PortVisibility.Visible
    } {
        id: 'port2',
        offset: {
            x: 1,
            y: 0.5
        },
        visibility: PortVisibility.Visible
    },
    {
        id: 'port3',
        offset: {
            x: 0.5,
            y: 0
        },
        visibility: PortVisibility.Visible
    },
    {
        id: 'port4',
        offset: {
            x: 0.5,
            y: 1
        },
        visibility: PortVisibility.Visible
    }
];
// initialize Diagram component
function App() {
  return (
    <DiagramComponent
      id="container"
      ref={(diagram) => (diagramInstance = diagram)}
      width={'100%'}
      height={'600px'}
      created = { () => {
        // Method to add ports through run time
        diagramInstance.addPorts(diagramInstance.nodes[0], port);
      }}
      // Add node
      nodes={node}
      // render initialized Diagram
    />
  );
}
const root = ReactDOM.createRoot(document.getElementById('diagram'));
root.render(<App />);

Remove ports at runtime

Remove ports at runtime by using client-side method removePorts. Refer to the following example which shows how to remove ports at runtime.

import * as React from "react";
import * as ReactDOM from "react-dom";
import { DiagramComponent, PortVisibility } from "@syncfusion/ej2-react-diagrams";
// A node is created and stored in nodes array.
let node = [{
        // Position of the node
        offsetX: 250,
        offsetY: 250,
        // Size of the node
        width: 100,
        height: 100,
        style: {
            fill: '#6BA5D7',
            strokeColor: 'white'
        },
        // Initialize port collection
        ports: [{
                id: 'port1',
                offset: {
                    x: 0,
                    y: 0.5
                },
                visibility: PortVisibility.Visible
            },
            {
                id: 'port2',
                offset: {
                    x: 1,
                    y: 0.5
                },
                visibility: PortVisibility.Visible
            },
            {
                id: 'port3',
                offset: {
                    x: 0.5,
                    y: 0
                },
                visibility: PortVisibility.Visible
            },
            {
                id: 'port4',
                offset: {
                    x: 0.5,
                    y: 1
                },
                visibility: PortVisibility.Visible
            }
        ]
    }];
let diagramInstance;
// initialize Diagram component
let ports = [{
        id: 'port1',
    }, {
        id: 'port2',
    }, {
        id: 'port3',
    }, {
        id: 'port4',
    }];
function App() {
    return (<DiagramComponent id="container" ref={(diagram) => (diagramInstance = diagram)} width={'100%'} height={'600px'} nodes={node} created={() => {
            diagramInstance.removePorts(diagramInstance.nodes[0], ports);
        }}/>);
}
const root = ReactDOM.createRoot(document.getElementById('diagram'));
root.render(<App />);
import * as React from "react";
import * as ReactDOM from "react-dom";
import {
    Diagram,
    DiagramComponent,
    NodeModel,
    Node,
    PointPortModel,
    PortVisibility
} from "@syncfusion/ej2-react-diagrams";
// A node is created and stored in nodes array.
let node: NodeModel[] = [{
    // Position of the node
    offsetX: 250,
    offsetY: 250,
    // Size of the node
    width: 100,
    height: 100,
    style: {
        fill: '#6BA5D7',
        strokeColor: 'white'
    },
    // Initialize port collection
    ports: [{
            id: 'port1',
            offset: {
                x: 0,
                y: 0.5
            },
            visibility: PortVisibility.Visible
        },
        {
            id: 'port2',
            offset: {
                x: 1,
                y: 0.5
            },
            visibility: PortVisibility.Visible
        },
        {
            id: 'port3',
            offset: {
                x: 0.5,
                y: 0
            },
            visibility: PortVisibility.Visible
        },
        {
            id: 'port4',
            offset: {
                x: 0.5,
                y: 1
            },
            visibility: PortVisibility.Visible
        }
    ]
}];
let diagramInstance:DiagramComponent;
// initialize Diagram component
let ports: PointPortModel[] = [{
            id: 'port1',
        }, {
            id: 'port2',
        }, {
            id: 'port3',
        }, {
            id: 'port4',
        }];
function App() {
  return (
    <DiagramComponent
      id="container"
      ref={(diagram) => (diagramInstance = diagram)}
      width={'100%'}
      height={'600px'}
      nodes={node}
      created={() => {
        diagramInstance.removePorts(diagramInstance.nodes[0], ports);
      }}
    />
  );
}
const root = ReactDOM.createRoot(document.getElementById('diagram'));
root.render(<App />);

Update port at runtime

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

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

import * as React from "react";
import * as ReactDOM from "react-dom";
import {
    Diagram,
    DiagramComponent,
    NodeModel,
    PortVisibility
} from "@syncfusion/ej2-react-diagrams";
// A node is created and stored in nodes array.
let node: NodeModel[] = [{
    // Position of the node
    offsetX: 250,
    offsetY: 250,
    // Size of the node
    width: 100,
    height: 100,
    style: {
        fill: '#6BA5D7',
        strokeColor: 'white'
    },
    // Initialize port collection
    ports: [{
        offset: {
            x: 0.5,
            y: 0.5
        },
        visibility: PortVisibility.Visible
    }]
}];
let diagramInstance:DiagramComponent;

// initialize Diagram component
function App() {
  return (
    <DiagramComponent
      id="container"
      ref={(diagram) => (diagramInstance = diagram)}
      width={'100%'}
      height={'600px'}
      nodes={node}
      created={() => {
        diagramInstance.nodes[0].ports[0].offset = {
            x: 1,
            y: 1
        };
        diagramInstance.dataBind();
      }}
    />
  );
}
const root = ReactDOM.createRoot(document.getElementById('diagram'));
root.render(<App />);

Appearance

  • The shape of port can be changed by using its shape property. To explore the different types of port shapes, refer to Port Shapes. If you need to render a custom shape, then you can set shape as path and define path using path data property of port.

  • The appearance of ports can be customized by using strokeColor, strokeWidth, and fill properties of the port.

  • Customize the port size by using the width and height properties of port.

  • The ports visibility property allows you to define, when the port should be visible.

The following code illustrates how to change the appearance of port.

import * as React from "react";
import * as ReactDOM from "react-dom";
import { DiagramComponent, PortVisibility } from "@syncfusion/ej2-react-diagrams";
// A node is created and stored in nodes array.
let node = [{
        // Position of the node
        offsetX: 250,
        offsetY: 250,
        // Size of the node
        width: 100,
        height: 100,
        style: {
            fill: '#6BA5D7',
            strokeColor: 'white'
        },
        // Initialize port collection
        ports: [{
                offset: {
                    x: 1,
                    y: 0.5
                },
                visibility: PortVisibility.Visible,
                //Set the style for the port
                style: {
                    fill: 'red',
                    strokeWidth: 2,
                    strokeColor: 'black'
                },
                width: 12,
                height: 12,
                // Sets the shape of the port as Circle
                shape: 'Circle'
            }]
    }];
// initialize Diagram component
function App() {
    return (<DiagramComponent id="container" width={'100%'} height={'600px'} nodes={node}/>);
}
const root = ReactDOM.createRoot(document.getElementById('diagram'));
root.render(<App />);
import * as React from "react";
import * as ReactDOM from "react-dom";
import {
    Diagram,
    DiagramComponent,
    NodeModel,
    PortVisibility
} from "@syncfusion/ej2-react-diagrams";
// A node is created and stored in nodes array.
let node: NodeModel[] = [{
    // Position of the node
    offsetX: 250,
    offsetY: 250,
    // Size of the node
    width: 100,
    height: 100,
    style: {
        fill: '#6BA5D7',
        strokeColor: 'white'
    },
    // Initialize port collection
    ports: [{
        offset: {
            x: 1,
            y: 0.5
        },
        visibility: PortVisibility.Visible,
        //Set the style for the port
        style: {
            fill: 'red',
            strokeWidth: 2,
            strokeColor: 'black'
        },
        width: 12,
        height: 12,
        // Sets the shape of the port as Circle
        shape: 'Circle'
    }]
}];
// initialize Diagram component
function App() {
  return (
    <DiagramComponent
      id="container"
      width={'100%'}
      height={'600px'}
      nodes={node}
    />
  );
}
const root = ReactDOM.createRoot(document.getElementById('diagram'));
root.render(<App />);

Offset

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

Constraints

The constraints property allows to enable/disable certain behaviors of ports. For more information about port
constraints, refer to Port Constraints.