Nodes in React Diagram component

25 Mar 202524 minutes to read

Nodes are graphical objects used to visually represent the geometrical information, process flow, internal business procedure, entity, or any other kind of data, and it represents the functions of a complete system regarding to how it interacts with external entities.

Node

Create node

A node can be created and added to the diagram either programmatically or interactively. The id property of a node is used to define its unique identifier and can later be used to find the node at runtime for customization. Nodes are stacked on the diagram area from bottom to top in the order they are added.

NOTE

When setting a Node’s ID, ensure that it does not contain white spaces, does not start with numbers or special characters, and does not include special characters like underscores (_) or spaces.

Add node through nodes collection

To create a node, define the node object and add that to nodes collection of the diagram model. The following code example illustrates how to add a node to the diagram.

import * as React from "react";
import * as ReactDOM from "react-dom";
import { DiagramComponent } 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'
        },
        // Text(label) added to the node
    }];
// initialize Diagram component
function App() {
    return (<DiagramComponent id="container" width={'100%'} height={'600px'} 
    // Add node
    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
} 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'
    },
    // Text(label) added to the node
}];
// 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 />);

NOTE

Node id should not begin with numbers(should begin with a letter). Node Id should be unique for all the shapes and connectors.

Add/Remove node at runtime

Nodes can be added at runtime by using public method, add and can be removed at runtime by using public method, remove. On adding node at runtime, the nodes collection is changed and the collectionChange event will trigger.

The following code illustrates how to add a node.

import * as React from 'react';
import * as ReactDOM from 'react-dom';
import { DiagramComponent } from '@syncfusion/ej2-react-diagrams';
let diagramInstance;
let node = [
  {
    // Position of the node
    offsetX: 250,
    offsetY: 250,
    // Size of the node
    width: 100,
    height: 100,
  },
];
// initialize Diagram component
function App() {
  const add = () => {
    diagramInstance.add(node[0]);
  };
  const remove = () => {
    diagramInstance.remove(diagramInstance.nodes[0]);
  };
  return (
    <div>
      <button onClick={add}>Add Node</button>
      <button onClick={remove}>Remove Node</button>
      <DiagramComponent
        id="container"
        ref={(diagram) => (diagramInstance = diagram)}
        width={'100%'}
        height={'600px'}
      />
    </div>
  );
}
const root = ReactDOM.createRoot(document.getElementById('diagram'));
root.render(<App />);
import * as React from 'react';
import * as ReactDOM from 'react-dom';
import { DiagramComponent, NodeModel } from '@syncfusion/ej2-react-diagrams';
let diagramInstance: DiagramComponent;
let node: NodeModel[] = [
  {
    // Position of the node
    offsetX: 250,
    offsetY: 250,
    // Size of the node
    width: 100,
    height: 100,
  },
];
// initialize Diagram component
function App() {
  const add = () => {
    diagramInstance.add(node[0]);
  };
  const remove = () => {
    diagramInstance.remove(diagramInstance.nodes[0]);
  };
  return (
    <div>
      <button onClick={add}>Add Node</button>
      <button onClick={remove}>Remove Node</button>
      <DiagramComponent
        id="container"
        ref={(diagram) => (diagramInstance = diagram)}
        width={'100%'}
        height={'600px'}
      />
    </div>
  );
}
const root = ReactDOM.createRoot(document.getElementById('diagram'));
root.render(<App />);

Add collection of nodes at runtime

  • The collection of nodes can be dynamically added using addElements method.Each time an element is added to the diagram canvas, the collectionChange event will be triggered.

The following code illustrates how to add nodes collection at run time.

import * as React from "react";
import * as ReactDOM from "react-dom";
import {DiagramComponent }from "@syncfusion/ej2-react-diagrams";
let diagramInstance;
// initialize nodes collection
var node = [
    { id: 'node1', offsetX: 140, offsetY: 250 ,annotations: [{ content: 'node1' }]},
    { id: 'node2', offsetX: 250, offsetY: 250 ,annotations: [{ content: 'node2' }]},
    { id: 'node3', offsetX: 360, offsetY: 250 ,annotations: [{ content: 'node3' }]}
];
// initialize Diagram component
function App() {
    return (<DiagramComponent id="container" ref={(diagram) => (diagramInstance = diagram)} width={'1500px'} height={'600px'}
    getNodeDefaults={(node) => {
        node.height = 100;
        node.width = 100;
        node.style.fill = '#6BA5D7';
        node.style.strokeColor = 'white';
        return node;
      }}
    created={() => {
            // Add collection of nodes 
            diagramInstance.addElements(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} from "@syncfusion/ej2-react-diagrams";

let diagramInstance:DiagramComponent;
//initialize node collection
var node:NodeModel= [
    { id: 'node1', offsetX: 35, offsetY: 260 ,annotations: [{ content: 'node1' }]},
    { id: 'node2', offsetX: 140, offsetY: 260 ,annotations: [{ content: 'node2' }]},
    { id: 'node3', offsetX: 240, offsetY: 260 ,annotations: [{ content: 'node3' }]}
];// initialize Diagram component
function App() {
    return (
      <DiagramComponent
      id="container"
      ref={(diagram) => (diagramInstance = diagram)}
      width={'1500px'}
      height={'600px'}
      getNodeDefaults={(node: NodeModel) => {
        node.height = 100;
        node.width = 100;
        node.style.fill = '#6BA5D7';
        node.style.strokeColor = 'white';
        return node;
      }}
        created={() => {
            // Add collection of nodes 
            diagramInstance.addElements(node);
        }}
      />
    );
  }
  const root = ReactDOM.createRoot(document.getElementById('diagram'));
  root.render(<App />);

Add node from palette

Nodes can be predefined and added to the palette, and can be dropped into the diagram when needed. For more information
about adding nodes from symbol palette, refer to Symbol Palette.

import * as React from 'react';
import * as ReactDOM from 'react-dom';
import { DiagramComponent, SymbolPalette,
    SymbolPaletteComponent, } from '@syncfusion/ej2-react-diagrams';
let diagramInstance;
let node = [
  {
    // Position of the node
    offsetX: 250,
    offsetY: 250,
    // Size of the node
    width: 100,
    height: 100,
  },
];
export function getBasicShapes() {
    let basicShapes = [
        {
            id: "Rectangle",
            shape: {
                type: "Basic",
                shape: "Rectangle",
            },
            height: 100,
            width: 100
        },
    ];
    return basicShapes;
}
// initialize Diagram component
function App() {
  return (
    <div  style={{width:'100%'}}>
        <div style={{float: 'left', width:'30%'}}>
         <SymbolPaletteComponent id="palette" width={'100%'} height={"700px"}
         palettes={[
            {
                id: 'basic',
                title: 'Basic Shapes',
                symbols: getBasicShapes(),
            },
        ]} 
    //Specifies the size of the symbol
    symbolHeight={80} symbolWidth={80} 
    //Sets the space to be left around a symbol
    symbolMargin={{
            left: 15,
            right: 15,
            top: 0,
            bottom: 15,
        }} />
         </div>
         <div style={{float: 'right', width:'70%'}}>
      <DiagramComponent
        id="container"
        ref={(diagram) => (diagramInstance = diagram)}
        width={'70%'}
        height={'700px'}
        nodes={node}
      />
      </div>
    </div>
  );
}
const root = ReactDOM.createRoot(document.getElementById('diagram'));
root.render(<App />);
import * as React from 'react';
import * as ReactDOM from 'react-dom';
import { DiagramComponent,
    SymbolPaletteComponent, NodeModel } from '@syncfusion/ej2-react-diagrams';
let diagramInstance: DiagramComponent;
let node: NodeModel[] = [
  {
    // Position of the node
    offsetX: 250,
    offsetY: 250,
    // Size of the node
    width: 100,
    height: 100,
  },
];
export function getBasicShapes() {
    let basicShapes = [
        {
            id: "Rectangle",
            shape: {
                type: "Basic",
                shape: "Rectangle",
            },
            height: 100,
            width: 100
        },
    ];
    return basicShapes;
}
// initialize Diagram component
function App() {
  return (
    <div  style={{width:'100%'}}>
        <div style={{float: 'left', width:'30%'}}>
         <SymbolPaletteComponent id="palette" width={'100%'} height={"700px"}
         palettes={[
            {
                id: 'basic',
                title: 'Basic Shapes',
                symbols: getBasicShapes(),
            },
        ]} 
    //Specifies the size of the symbol
    symbolHeight={80} symbolWidth={80} 
    //Sets the space to be left around a symbol
    symbolMargin={{
            left: 15,
            right: 15,
            top: 0,
            bottom: 15,
        }} />
         </div>
         <div style={{float: 'right', width:'70%'}}>
      <DiagramComponent
        id="container"
        ref={(diagram) => (diagramInstance = diagram)}
        width={'70%'}
        height={'700px'}
        nodes={node}
      />
      </div>
    </div>
  );
}
const root = ReactDOM.createRoot(document.getElementById('diagram'));
root.render(<App />);

Create node through data source

Nodes can be generated automatically with the information provided through dataSource property. The default properties for these nodes are fetched from default settings (getNodeDefaults). For more information about data source, refer to  DataBinding.

import * as React from 'react';
import * as ReactDOM from 'react-dom';
import {
  DiagramComponent,
  Inject,
  DataBinding,
} from '@syncfusion/ej2-react-diagrams';
import { DataManager, Query } from '@syncfusion/ej2-data';
let diagramInstance;
let data = [
  {
    id: 'data1',
    parent: null,
  },
];
let items = new DataManager(data, new Query().take(7));
// initialize Diagram component
function App() {
  return (
    <DiagramComponent
      id="container"
      ref={(diagram) => (diagramInstance = diagram)}
      width={'100%'}
      height={'700px'}
      getNodeDefaults={(node) => {
        node.height = 100;
        node.width = 100;
        node.offsetX = 300;
        node.offsetY = 200;
        node.style = { fill: 'yellow', strokeColor: 'yellow' };
        return node;
      }}
      dataSourceSettings=
    >
      <Inject services={[DataBinding]} />
    </DiagramComponent>
  );
}
const root = ReactDOM.createRoot(document.getElementById('diagram'));
root.render(<App />);
import * as React from 'react';
import * as ReactDOM from 'react-dom';
import {
  DiagramComponent,
  Inject,
  DataBinding,
} from '@syncfusion/ej2-react-diagrams';
import { DataManager, Query } from '@syncfusion/ej2-data';
let diagramInstance: DiagramComponent;
let data: any = [
  {
    id: 'data1',
    parent: null,
  },
];
let items: any = new DataManager(data, new Query().take(7));
// initialize Diagram component
function App() {
  return (
    <DiagramComponent
      id="container"
      ref={(diagram) => (diagramInstance = diagram)}
      width={'100%'}
      height={'700px'}
      getNodeDefaults={(node) => {
        node.height = 100;
        node.width = 100;
        node.offsetX = 300;
        node.offsetY = 200;
        node.style = { fill: 'yellow', strokeColor: 'yellow' };
        return node;
      }}
      dataSourceSettings=
    >
      <Inject services={[DataBinding]} />
    </DiagramComponent>
  );
}
const root = ReactDOM.createRoot(document.getElementById('diagram'));
root.render(<App />);

Draw nodes

Nodes can be interactively drawn by clicking and dragging the diagram surface.

To draw a shape, you have to activate the drawing tool by setting DrawOnce or ContinuousDraw to the tool property and you need to set the node object by using the drawingObject property. The following code example illustrates how to draw a rectangle at runtime.

import * as React from 'react';
import * as ReactDOM from 'react-dom';
import { DiagramComponent, DiagramTools } from '@syncfusion/ej2-react-diagrams';
let diagramInstance;
// initialize Diagram component
function App() {
  return (
      <DiagramComponent
        id="container"
        ref={(diagram) => (diagramInstance = diagram)}
        width={'100%'}
        height={'700px'}
        created={() => {
            //JSON to create a rectangle
            let drawingshape = {
              type: 'Basic',
              shape: 'Rectangle',
            };
            let node = {
              shape: drawingshape,
            };
            diagramInstance.drawingObject = node;
            //To draw an object once, activate draw once
            diagramInstance.tool = DiagramTools.ContinuousDraw;
            diagramInstance.dataBind();
          }}
      />
  );
}
const root = ReactDOM.createRoot(document.getElementById('diagram'));
root.render(<App />);
import * as React from 'react';
import * as ReactDOM from 'react-dom';
import { DiagramComponent, DiagramTools } from '@syncfusion/ej2-react-diagrams';
let diagramInstance: DiagramComponent;
// initialize Diagram component
function App() {
  return (
      <DiagramComponent
        id="container"
        ref={(diagram) => (diagramInstance = diagram)}
        width={'100%'}
        height={'700px'}
        created={() => {
            //JSON to create a rectangle
            let drawingshape = {
              type: 'Basic',
              shape: 'Rectangle',
            };
            let node = {
              shape: drawingshape,
            };
            diagramInstance.drawingObject = node;
            //To draw an object once, activate draw once
            diagramInstance.tool = DiagramTools.ContinuousDraw;
            diagramInstance.dataBind();
          }}
      />
  );
}
const root = ReactDOM.createRoot(document.getElementById('diagram'));
root.render(<App />);

Update node at runtime

You can modify any node properties at runtime, and the changes will be instantly reflected. For example, here you can change the size and color of the node.

import * as React from 'react';
import * as ReactDOM from 'react-dom';
import { DiagramComponent } from '@syncfusion/ej2-react-diagrams';
let diagramInstance;
let node = [
  {
    // Position of the node
    offsetX: 250,
    offsetY: 250,
    // Size of the node
    width: 100,
    height: 100,
    style: { fill: '#6AA8D7',strokeWidth:1},
  },
];
// initialize Diagram component
function App() {
  const color = () => {
      if(diagramInstance.nodes[0].style.fill === '#6AA8D7'){
        diagramInstance.nodes[0].style.fill = 'orange';
      }
      else{
        diagramInstance.nodes[0].style.fill = '#6AA8D7';
      }
  };
  const size = () => {
    if(diagramInstance.nodes[0].width === 100){
        diagramInstance.nodes[0].width = 200;
      }
      else{
        diagramInstance.nodes[0].width =100;
      }
  };
  return (
    <div>
      <button onClick={color}>Change Color</button>
      <button onClick={size}>Change Size</button>
      <DiagramComponent
        id="container"
        ref={(diagram) => (diagramInstance = diagram)}
        nodes={node}
        width={'100%'}
        height={'600px'}
      />
    </div>
  );
}
const root = ReactDOM.createRoot(document.getElementById('diagram'));
root.render(<App />);
import * as React from 'react';
import * as ReactDOM from 'react-dom';
import { DiagramComponent, NodeModel } from '@syncfusion/ej2-react-diagrams';
let diagramInstance: DiagramComponent;
let node: NodeModel[] = [
  {
    // Position of the node
    offsetX: 250,
    offsetY: 250,
    // Size of the node
    width: 100,
    height: 100,
    style: { fill: '#6AA8D7',strokeWidth:1},
  },
];
// initialize Diagram component
function App() {
  const color = () => {
      if(diagramInstance.nodes[0].style.fill === '#6AA8D7'){
        diagramInstance.nodes[0].style.fill = 'orange';
      }
      else{
        diagramInstance.nodes[0].style.fill = '#6AA8D7';
      }
  };
  const size = () => {
    if(diagramInstance.nodes[0].width === 100){
        diagramInstance.nodes[0].width = 200;
      }
      else{
        diagramInstance.nodes[0].width =100;
      }
  };
  return (
    <div>
      <button onClick={color}>Change Color</button>
      <button onClick={size}>Change Size</button>
      <DiagramComponent
        id="container"
        ref={(diagram) => (diagramInstance = diagram)}
        nodes={node}
        width={'100%'}
        height={'600px'}
      />
    </div>
  );
}
const root = ReactDOM.createRoot(document.getElementById('diagram'));
root.render(<App />);

NOTE

Once the property is updated, you should call the dataBind to reflect the changes instantly.

Clone node at runtime

Cloning a node creates a new node instance with identical properties and attributes. You can clone a node using the copy and paste public methods of the diagram model.

The following code example illustrates how to clone node at runtime

import * as React from 'react';
import * as ReactDOM from 'react-dom';
import { DiagramComponent } from '@syncfusion/ej2-react-diagrams';
let diagramInstance;
let node = [
  {
    // Position of the node
    offsetX: 250,
    offsetY: 250,
    // Size of the node
    width: 100,
    height: 100,
    style: { fill: '#6AA8D7', strokeWidth: 1 },
  },
];
// initialize Diagram component
function App() {
  const clone = () => {
    let selectedNode =
      diagramInstance.selectedItems.nodes.length > 0
        ? diagramInstance.selectedItems.nodes[0]
        : diagramInstance.nodes[0];
    diagramInstance.select([selectedNode]);
    diagramInstance.copy();
    diagramInstance.paste();
  };
  return (
    <div>
      <button onClick={clone}>Clone Node</button>
      <DiagramComponent
        id="container"
        ref={(diagram) => (diagramInstance = diagram)}
        nodes={node}
        width={'100%'}
        height={'600px'}
      />
    </div>
  );
}
const root = ReactDOM.createRoot(document.getElementById('diagram'));
root.render(<App />);
import * as React from 'react';
import * as ReactDOM from 'react-dom';
import { DiagramComponent, NodeModel } from '@syncfusion/ej2-react-diagrams';
let diagramInstance: DiagramComponent;
let node: NodeModel[] = [
  {
    // Position of the node
    offsetX: 250,
    offsetY: 250,
    // Size of the node
    width: 100,
    height: 100,
    style: { fill: '#6AA8D7',strokeWidth:1},
  },
];
// initialize Diagram component
function App() {
  const clone = () => {
    let selectedNode =
      diagramInstance.selectedItems.nodes.length > 0
        ? diagramInstance.selectedItems.nodes[0]
        : diagramInstance.nodes[0];
    diagramInstance.select([selectedNode]);
    diagramInstance.copy();
    diagramInstance.paste();
  };
  return (
    <div>
      <button onClick={clone}>Clone Node</button>
      <DiagramComponent
        id="container"
        ref={(diagram) => (diagramInstance = diagram)}
        nodes={node}
        width={'100%'}
        height={'600px'}
      />
    </div>
  );
}
const root = ReactDOM.createRoot(document.getElementById('diagram'));
root.render(<App />);

Add nodes from tree view

By customizing the dragEnter functionality, you can allow elements from other components, such as the tree view, to be converted into nodes based on the data of the dragged element.

See Also